Eben van Tonder · 8 October 2026

Eight log basins sunk into the ground above Hallstatt held salted pork in the 13th and 12th centuries BCE. They are the earliest European centre known at present where pork curing appears as an organised technological system, about a thousand years before the earliest surviving European written instructions for salting ham. Their importance lies not only in their age, but in the combination of selected animals, a systematic division of the carcass, salting on a large scale and conditions for long maturation. In the same centuries, weaving techniques and crops moved across Eurasia between central Europe and western China, and many people moved from the continent to Britain.

Hallstatt in winter. The prehistoric mines lie in the high valley above the town.

Not Every People Used Salt

Many histories of food assume that all societies valued salt. This is not correct. Micah Leshem reviewed the research on salt appetite in humans and concluded that “human salt intake does not fit the biological model of a regulated sodium appetite”^[1]. Animals that lack sodium look for it. According to Leshem, people learn to like salt as a flavour through development, conditioning, habit and the food of their culture^[1]. Other physiologists report that people do crave salt when they lack sodium, so this is still debated^[2]. I wrote about the oldest source of sodium in the human diet, meat itself, in The Salt in Meat.

Several peoples did without salt. New Zealand has no rock salt. James Cook saw Polynesians make salt in Hawaii in the 1770s, but the Māori of New Zealand never made it^[3]. I wrote about this in Searching for Salt in New Zealand. In southern Africa, Dr Xander Antonites of the Department of Anthropology and Archaeology at the University of Pretoria told me that indigenous peoples did not use salt widely as a preservative or as a seasoning. His own excavations at the Baleni spring in the Lowveld add detail. Farmers made salt there over 2,000 years, but only from time to time^[4], and Antonites describes the work of the Early Iron Age as small in scale, part time or seasonal^[5]. In West Africa I found that people preserved meat by drying it in the sun, by cooking it and by deep frying it. I describe this in three earlier articles (deep frying, suya and African meat curing).

In Europe and Asia, however, salt was known very early. People used the salt spring of Poiana Slatinei in Romania between 6050 and 5500 BCE^[6]. At Zhongba in central China, archaeology and chemistry confirm salt making in the first millennium BCE, and the oldest phase of the site dates to about 2000 BCE^[7]. Europeans therefore knew salt for thousands of years before Hallstatt. Salting pork in large quantities is a separate development, and it needs its own explanation.

How I Came to Hallstatt

Christa van Tonder-Berger studies Austrian history and local culture. Early in 2024 she wrote to me about Hallstatt and its possible connection with the Turpan region of western China. I had worked on Turpan for years and had written two chapters about it in Bacon & the Art of Living (From Sea to Deserts and Ammonia from Urine and Horse Sweat). Her emails made Hallstatt the centre of my search for the origin of salted meat in Europe. They also led me to the excavation reports of the Natural History Museum in Vienna and of the Austrian Academy of Sciences, and this article is based on those reports. The question of the article is how a recognisable system of pig selection, carcass division, salting, maturation and use of secondary products became established across central and western Europe, and why related methods lasted into the modern period.

The Curing Basins of Hallstatt

Hallstatt is in the Salzkammergut in Upper Austria. The prehistoric mines are in a narrow high valley, the Salzbergtal (Salt Mountain Valley), about 1,000 m above sea level^[8]. According to Hans Reschreiter of the Natural History Museum in Vienna, a tool of stag antler found there in 1838 dates from about 5000 BCE^[9]. Underground mining began by about 1500 BCE and reached depths of up to 170 m^[8]. The meat industry dates from this Bronze Age period of mining.

Date	13th to 12th century BCE
Basins known	8, of which 2 investigated
Capacity	150 to 200 carcasses per basin
Throughput	several hundred pigs per year
Slaughter age	1.5 to 2 years
Time in salt	7 to 10 days
Mine climate	6 to 8 °C, 60% humidity
Weight loss	one third in six months

The Hallstatt meat industry in figures. The date, the number of basins, the capacity, the yearly throughput and the age at slaughter come from the excavation and bone reports^{[8, 10, 11, 12]}. The time in salt, the climate of the mine and the loss of weight come from the reconstruction and experiments of Barth and Lobisser^[13].

Discovery and Dating

Since the 19th century, excavators have found several log structures sunk into pits on the mountain. One was recorded in 1877, and Friedrich Morton excavated a second in 1939^{[10, 14]}. Morton’s structure had double walls sealed with clay. Because it contained many everyday objects, scholars first thought that these structures were Celtic houses of the Late Iron Age. Later they thought they were basins for collecting natural brine^[10]. Radiocarbon dates from the 1990s showed that both ideas were wrong. The basins date from the 13th and 12th centuries BCE, which is the Late Bronze Age^[10]. A thick layer of animal bones near them has the same radiocarbon date^{[8, 11]}. Eight basins are now known, and archaeologists have investigated and recorded two of them^[10].

The basins must be placed beside the history of the mine. The oldest evidence of salt mining at Hallstatt dates from the 15th century BCE^[15]. Bronze Age mining ended around 1245 BCE, when a debris flow buried the workings, and tree ring dating of the timber in the Christian von Tuschwerk gives 1245 BCE as the end year^{[15, 16]}. A study of more than 2,000 wood samples dated 763 of them. Its tree ring chronologies run from 1393 to 1286 BCE for larch, from 1232 to 1063 BCE for fir and from 1182 to 1062 BCE for beech^[17]. Wood was therefore still being cut and used in the Hallstatt sites after the debris flow. The radiocarbon dates of the basins, in the 13th and 12th centuries BCE, cannot show whether they were used before or after 1245 BCE^[10]. If salting continued after the mine was buried, the salt must have come from other workings or from stores. This question is still open. Iron Age mining began in the 9th century BCE in another part of the mountain^[15].

DATE	EVENT AT HALLSTATT
About 5000 BCE	Stag antler tool, found in 1838[9]
15th century BCE	Oldest evidence of salt mining[15]
1393 to 1286 BCE	Larch tree ring chronology from the Hallstatt sites[17]
1344 and 1343 BCE	Timber of the oldest preserved wooden staircase in Europe[16]
13th and 12th centuries BCE	Curing basins, dated by radiocarbon[10]
About 1245 BCE	Debris flow ends Bronze Age mining[15, 16]
1232 to 1062 BCE	Fir and beech tree ring chronologies from the Hallstatt sites[17]
9th century BCE	Iron Age mining begins in another part of the mountain[15]
About the middle of the 4th century BCE	Iron Age mining ends[18, 19]

The mine and the basins in time. The basins are dated by radiocarbon, the mine by tree rings and finds.

Did the Meat Industry Outlive the Bronze Age Mine?

The dating leaves a question that could test the whole argument. Did pork processing continue after the debris flow of 1245 BCE? If it did, curing had become an economic activity with some independence from the workings that first made it possible. The sequence would then run from a salt mine that created an opportunity, to meat processing that developed around it, to meat processing established firmly enough to survive the loss of the mine. Precise dating of the basins, for example by tree rings from their timbers, could answer this.

A log basin in the Salzbergtal. Basins of this kind were first thought to be houses.

The Bones

Erich Pucher studied the animal bones. Most of them are pig bones, whereas cattle bones are the most common in most prehistoric settlements of central Europe^[11]. The pigs were killed when they were one and a half to two years old, and there are almost no younger or older animals. A Hallstatt pig measured about 110 cm from the snout to the base of the tail^[11]. The narrow age range is consistent with slaughter mainly in winter, as Pucher reconstructs it from the age of the animals and the probable birth season of early domestic pigs^[11].

The sex of the animals gives the clearest evidence of selection. Pucher counted 102 male jaws and only nine female jaws, which he calls an extreme imbalance compared with what is found on rural settlements of the Bronze Age. He considers the males to have been castrated, presumably for better tasting meat, and the cattle, sheep and goats also show a predominance of castrated animals in their prime^[11]. The ten teeth that were later used for DNA analysis also came mostly from castrated males^[8]. Hallstatt therefore did not receive an ordinary cross section of the pig population. It received animals selected by sex, age and probably castration, which points to a specialised supply of meat.

The repeated arrival of mainly castrated males within a narrow age range from more than one supply area is unlikely to represent an ordinary cross section of the surrounding pig population. It points to deliberate selection somewhere in the supply chain. Selection means choosing animals from whatever arrives. Specification means that the supply chain repeatedly delivers a desired type, and the Hallstatt pattern comes closer to the second. The selection may have happened at Hallstatt, at the supplying farms, through traders or through an established convention of the market, and the evidence does not yet show which. The basins show processing, while the animals show a specification.

Castration deserves attention for its own sake. Pucher explains it by the taste of the meat^[11], but castration also changes growth, behaviour and fat. A modern review finds that castrated males carry more backfat and less lean meat than entire boars, and that entire males are more aggressive^[20]. In a curing economy the composition of the carcass is important, because fat protects the meat and affects how it dries. If the pigs were castrated, raised towards a certain fatness and killed at a narrow age, the production system reached back from the curing basin into husbandry. The chain then ran from breeding and castration through feeding, slaughter age, carcass preparation and transport to salting, maturation and distribution. How castration, age and feeding on mast shaped the Hallstatt carcass is a question that the bones alone cannot yet answer.

The high valley was a poor place to keep animals. No settlement or cemetery of the Bronze Age has yet been found there, although Late Bronze Age settlement pottery and the need to maintain the mine day and night suggest that people lived near the workings^[21]. Whether the salters were miners, seasonal workers or specialists is not known. The Vienna team therefore concludes that cuts of meat, mostly pork, were carried up into the valley^{[11, 12]}. The shape of the bones points to two supply areas. One was to the north along the Traun river, and the other to the southeast towards the Styrian Salzkammergut^[8]. A pilot study of mitochondrial DNA obtained complete sequences from seven of the ten teeth. The genetic variety was almost as high as in pigs and wild boar today, which suggests that the pigs came from large herds or from several farms. The authors point out that the study is based on few animals and on one genetic marker, and that it cannot show where the pigs came from^[8].

The butchers cut the pigs in a fixed way. Thousands of pig bones show the same technique^[8], which Fritz Eckart Barth describes as an old method of cutting up pigs^[14]. Most bones of the trunk are missing from the finds. Pucher therefore concludes that the trunk was removed together with the entrails, and that the pigs reached the high valley as carcasses from which the spine and ribs had already been taken out^[11]. The museum describes the method. The pig was laid on its belly, opened from the back and gutted, and all the bones from the tail to the skull were removed together with the ribs and the entrails^[12]. The long bones carry no cut marks^[11], and they were mostly removed only on the mountain, where leg bones and lower jaws are found in large numbers^[12]. The meat therefore entered the valley as partly deboned carcasses and not as whole animals. The museum suggests that the carcasses were hung from a pole and carried on the shoulders, and that the lower jaws may have served as handles, although it presents this only as a possible explanation^{[11, 12]}.

How the Basins Worked

Barth and Wolfgang Lobisser proposed how the basins were used, and Christa van Tonder-Berger translated their German text for my study of the Hallstatt method^{[13, 22]}. Up to twelve rows of beams were sunk into the ground, and the outside was sealed with clay. The basins were filled with a dense blue clay. Barth and Lobisser identify it as dissolved Haselgebirge, the clay rock of the mountain that contains salt. The clay held many animal bones, mostly pig jaws and long bones, and broken pieces of thick pots made of graphite clay^[13].

From these finds they concluded that the structures were brine basins sunk into the ground. The pork was buried in small pieces of rock salt or in salty Haselgebirge for seven to ten days^[13]. Experiments reported by the museum agree with this, because enough salt had entered the meat after ten days^[12]. A narrow gap on the north side of the basin found in 1877 probably collected the brine that came out of the meat^[13]. After salting, the meat had to be dried and aged, and the mine was suitable for this. Barth and Lobisser report a steady temperature of 6 to 8 °C and a humidity of 60 per cent. The air moved strongly through the galleries, and it was salty and smoky from the open lights. Pieces of meat hung in the present mine lost one third of their weight in six months and did not dry out^[13].

Both publications state the limits of this reconstruction. Barth and Lobisser write that their experiments do not prove that fine raw ham was made at Hallstatt in the Bronze Age, although the conditions for it existed^[13]. The Academy volume states its conclusion in one sentence. „Im Zusammenhang betrachtet kann von einem Pökelverfahren in Surbecken ausgegangen werden.“ (Taken together, a curing process in brine basins can be assumed.)^[14] Reschreiter and Kowarik also note that the miners hanging salted meat on drying racks in their illustration of the mine are not supported by specific finds^[23]. The basins, the bones and the cutting marks are archaeological evidence. The length of salting, the hanging and the loss of weight come from reconstruction and experiment.

Nothing from the slaughter was wasted, as the cooking pots of graphite clay show. The bones were boiled until the liquid set to a jelly, and the jelly could be dried^[14]. Barth and Lobisser suggest that the brine from the basins was boiled down in the same pots^[13]. The German summary of the Academy volume therefore speaks of salted meat and meat extracts^[14]. The metal finds show a further chemical trace. Copper and bronze objects from the basins have a coating of covellite, a copper sulfide, which Seemann and Brandstätter explain by the sulfur in the meat and by storage in the clay rich Haselgebirge^[14].

The Basin as Equipment

The narrow gap beside the basin found in 1877 probably collected the brine that came out of the meat^[13]. If it was built for this purpose, the basin was more than a container. Its construction took account of a physical consequence of salting, namely that salt draws liquid out of the meat, and the builders needed no theory of osmosis to know this. A pot of salted meat shows preservation. A purpose built structure that holds meat and salt and drains the brine shows process engineering. Barth and Lobisser describe brine that was used again until it spoiled, and they suggest that brine was boiled down in the pots of graphite clay^[13]. The gap may therefore have served two purposes, the reuse of brine and the making of extract.

Reused brine has a long later history. In my review of the history of bacon curing I show that the industrial bacon plants of Denmark and the tank cure of Wiltshire were based on old brine that was kept and used again^[24]. The old Wiltshire brine contained nitrate from saltpetre, and bacteria in the brine changed the nitrate into nitrite, so that an old brine cured faster and gave a better red colour than a fresh one^[24]. The enzyme responsible is the nitrate reductase of staphylococci^[25]. Wiltshire curers learned this by practice long before Polenske found nitrite in curing brine in 1891^[26].

Was the reason for collecting brine at Hallstatt the same? Part of it may have been. A reused brine already contains a substantial concentration of salt and of material dissolved from the meat, although its salt content depends on how it was first made, how much liquid the meat added and whether salt was added later. Reuse could have reduced the need for fresh salt, depending on the concentration of the recovered brine and how it was used, and Bronze Age salters could have noticed, as Wiltshire curers did, that such a brine behaved differently from a fresh one. However, the Wiltshire effect on colour and speed depends on nitrate, and no source reports nitrate in the Hallstatt salt, the Haselgebirge or the basins^{[13, 14]}. Without nitrate, a reused brine at Hallstatt could have saved salt, but it could not have produced the nitrite cure of Wiltshire. Mineral analysis of the clay fill of the basins for nitrate, nitrite, chloride, sulphate and other ions would test this. Microbial traces would be far harder to interpret, because ancient DNA and biomarkers are easily confused with later contamination and with organisms from the surrounding soil.

1. Supply. Cuts from pigs aged one and a half to two years are carried up into the valley, probably after slaughter in winter.
2. Salting in the basin. The meat lies on the bone in rock salt or Haselgebirge for seven to ten days.
3. Brine. Liquid from the meat collects in a gap beside the basin, where it can be scooped out.
4. Drying and ageing in the mine. The pieces hang in the mine at 6 to 8 °C in salty and smoky air that moves through the galleries. Test pieces lost one third of their weight in six months.
5. Extract. Bones and brine are boiled in pots of graphite clay until the liquid sets, and the jelly is dried.

The Hallstatt process as Barth and Lobisser reconstruct it^[13], with the findings of the Natural History Museum in Vienna on supply and butchery^{[11, 12]}.

Scale

The basins measured about 4 by 4 m^[23]. The museum estimates that 150 to 200 pigs went into one basin in one batch^[12]. Because the pigs arrived as partly deboned carcasses, this figure counts animals and not intact carcasses. Hammer and his colleagues estimate that the meat of several hundred pigs was processed each year^[8]. Archaeologists conclude from the size of the basins and the quantity of bones that the valley produced more than its own people needed^[10]. Where the rest of the meat went is still an open research question, and it is one of the central questions of this article. Three economic models are possible. Hallstatt may have made food mainly for the miners and the communities around them. It may have exported preserved pork as a commodity. Or part of the pork may have fed the mining economy while the surplus entered the same exchange through which Hallstatt salt travelled. The third seems the most likely to me, but the evidence cannot yet decide between them. If much cured pork left Hallstatt, the mine was not only a place where a technology was practised, but a possible centre from which both the product and the knowledge spread. Pucher, Barth and their colleagues therefore speak of large scale production of salted meat, ham and bacon^[14], and the DNA team called its paper “Bronze Age meat industry”^[8]. Industry is used in this article in the archaeological sense of organised, specialised production beyond ordinary household processing, and not in the modern sense of mechanised factory production. I know of no older installation of this kind in Europe.

Were the eight basins used at the same time, by season, one after another or as replacements for one another? How they were used changes the estimate of annual capacity, and the dating, wear, repairs, stratigraphy and position of the basins could test it. If slaughter was concentrated in winter, Hallstatt also had to absorb a large wave of carcasses in a short time. Supply, slaughter, transport, salt, space in the basins, labour and space for maturation all had to be coordinated. The throughput itself implies organisation, even without kings, administrators or written accounts.

A rough estimate shows the scale of the salt needed. It does not reconstruct the Bronze Age recipe. Frost calculates that a pig of eight months can yield up to fifty kilograms of meat, fat and other products^[27]. If a Hallstatt carcass section entering the basin weighed between 30 and 50 kg, one batch of 150 to 200 pigs held between about 4.5 and 10 tonnes of meat. Finished dry cured hams today contain about 3 to more than 7 per cent salt^[28]. On these assumptions the meat of one batch took up between about 140 and 700 kg of salt, while the salt or Haselgebirge packed around the meat must have weighed much more. Each batch therefore consumed salt in the order of hundreds of kilograms to tonnes, which supports the view that meat processing gave a use to a large amount of lower grade material. This calculation estimates only the order of magnitude. The final salt content after drying cannot be converted directly into the salt taken up at the start, because the loss of water concentrates the salt already present. No estimate of the Bronze Age output of the mine is available to me for comparison. How many people were needed to receive the carcasses, finish the deboning, handle the salt, load and empty a basin, hang the meat and process the bones and brine is also unknown. Experimental archaeology could measure it, and a process that needs coordinated teams differs in kind from curing in a household.

Hallstatt Seen by a Meat Processor

A modern producer of raw ham or Speck makes the same decisions that the Hallstatt evidence shows. These comparisons are my own.

The raw material was uniform. The pigs were all of about the same age^[11], and the teeth that were tested came mostly from castrated males^[8]. Today we would call this a raw material specification.

The season and the place kept the meat cold. The pigs were probably killed in winter^[11], the valley is about 1,000 m above sea level^[8], and the mine stayed at 6 to 8 °C^[13]. A study of dry cured ham tested salting at 0, 2 and 6 °C, and within that range the temperature had no significant effect on the loss of water^[29]. The Hallstatt salters probably worked in natural cold. However, no source shows that they chose winter for this reason.

Drying was slow. The meat lost one third of its weight in six months at a steady temperature and in moving air^[13]. The smoke in the mine came from the lights, so the meat was exposed to smoke without being smoked on purpose. Smoke phenols act as antioxidants, and smoke carbonyl compounds slow the growth of microbes^[30], but the contribution of the smoke at Hallstatt has not been measured. The jelly made from bones and brine shows that the salters also used the bones and the brine^{[13, 14]}.

The experiments show that maturation was possible under these conditions. The microbiological stability of the prehistoric products cannot be judged without knowing their final salt and moisture contents.

One limit applies to the word curing. All sources describe rock salt or Haselgebirge^{[13, 14]}, and none of the sources I consulted reports nitrate or nitrite in the basins. In this article, curing at Hallstatt therefore means salting and drying. These are different operations. Salting brings salt into the meat, drying removes water, and smoke adds chemical compounds to the surface. Curing in the narrow sense adds nitrate or nitrite. Stability against microbes is the result of all these operations together and not of one of them alone. We do not know whether the meat turned red as cured meat does, or by which reactions. I describe possible reactions as hypotheses in The Hallstatt Curing Method.

The Hallstatt Production System

Hallstatt shows more than the salting of pork. It shows a set of operations that worked together as one production system. Archaeologists found the evidence for some operations directly, and the experiments of Barth and Lobisser support others. Together they formed a production system.

The Operations

Pigs were raised outside the processing centre and brought in^{[8, 11]}. They were selected within a narrow age range of one and a half to two years^[11], and they were probably killed in winter^[11]. The carcasses were divided in a standard way, and the meat was processed on the bone^{[8, 11, 14]}. The meat was salted in basins of rock salt or salty clay, and the brine that came out of it was collected^[13]. The salted meat was aged in the cold mine, in moving air that carried salt and smoke^[13]. Bones and brine were boiled to make jelly^{[13, 14]}, and the basins held more meat than the valley needed^{[10, 12]}. The selection of animals and the division of the carcass are shown directly by the bones. The details of salting and ageing come from reconstruction^{[13, 23]}.

Each of these operations can arise independently. Salting meat, smoking meat and killing pigs in winter are obvious solutions, and many peoples found them. What Hallstatt shows is the stable combination of all of them in one repeatable system, and it is the earliest place known at present where this combination can be seen in operation.

Three Levels of Standardisation

Hallstatt shows standardisation at three levels. The animals were unusually uniform in sex, age and probably castration^[11]. The carcasses were divided by a repeated anatomical procedure, opened from the back with the spine and ribs removed^{[11, 12]}. The meat then entered a repeated preservation process of basin salting, management of the brine and maturation in the mine^[13]. Any one of these could occur by chance or independently. Together they are much harder to dismiss as ordinary household preservation, and they are one of the strongest reasons to treat Hallstatt as an organised production system.

Standardisation does not require written specifications. Repeated selection of similar animals, repeated division of the carcass and repeated treatment can produce consistent output through learned judgement. The cues were the age, sex and fatness of the animal, the size of the piece, the number of days, the feel and appearance of the meat, the weather, the season and the place. Hallstatt therefore suggests quality control by practice long before quality was expressed in numbers, as the section on practice before theory describes for later periods.

Supply and Processing Were Separate

The pigs came from at least two supply areas, while the people in the valley processed them^{[8, 11]}. Farms produced the pigs, and Hallstatt concentrated the processing. The salt mine supplied the means of preservation, and its galleries supplied a cold place for ageing^[13]. The scale of production points to an outlet beyond the valley^[10]. This division between primary production and processing is the outline of a supply chain in a meat industry, more than 3,000 years ago, and it is the reason the Vienna team speaks of a Bronze Age meat industry^[8].

Why Bring the Meat to Hallstatt?

Reschreiter and Kowarik give two reasons why meat processing became important in the Salzbergtal. It was probably simpler to bring the pigs to Hallstatt than to bring the salt to the pigs, and the mine was the perfect place to smoke and cure meat^[23]. A third reason concerns the salt itself. According to the museum, the meat was not cured with the pure rock salt of high quality, but with Haselgebirge, a lower grade waste product that is a mixture of salt, clay and anhydrite^[12]. The Bronze Age mining technique also yielded salt mainly in small chips, and larger tablets could be removed only where natural rock movements had opened clefts and fissures^[15]. Small chips and Haselgebirge are awkward to trade as blocks, but they can be packed around meat. Curing meat therefore made use of material that was less suitable for sale as salt. This is my interpretation of the museum’s statements, and it would make the processing of meat at the mine economically sensible. In the Bronze Age, Hallstatt was probably the only big supplier of rock salt in the Eastern Alps^[31].

The economic logic goes further. Pigs are bulky and fresh pork spoils. Salt in small chips or mixed with clay has less value in transport than clean salt. Combined at the mine, the two became preserved pork. Good salt could leave Hallstatt as salt, while poorer salt could leave it inside the meat. This would be value added at the source, and it would make Hallstatt a specialised processing economy and not only a place where miners preserved their food. The system may in fact have used three streams of material. Good salt could be sold, poorer salt preserved meat, and bones and brine became jelly and extract^{[13, 14]}. To draw the highest value from each material is the principle of a modern integrated meat plant, although the technology was not modern. This remains a hypothesis. Whether Hallstatt salt was graded, and whether better salt was sent away while poorer salt stayed at the mine, has still to be investigated.

Preservation also made the meat transportable. A live pig can walk, but it needs feed, water and herding. Fresh pork spoils within days, and salt is heavy. The salted and dried pork of the reconstruction lost about one third of its weight in six months^[13]. It became lighter and could be kept for months. Preservation therefore turned the pig into a carcass, the carcass into salted pork and the salted pork into goods that could travel. This second change helps to explain the later trade in Gaulish pork that Roman writers describe^{[32, 33]}.

The mine also offered a place for maturation that needed no building. The museum gives an average temperature of 7 °C and a humidity of 60 per cent, with air that moved strongly and carried salt and smoke^[12]. Modern specifications for Alpine Speck give comparable conditions. Gailtaler Speck matures in a well ventilated room at 8 to 16 °C and 60 to 80 per cent relative humidity^[34], and Tiroler Speck is dried in air below 17 °C at 60 to 90 per cent^[35]. The mine therefore provided, throughout the year, conditions at the cool and dry end of what Alpine producers use today.

Hammer and colleagues ask which farms supplied pigs to Hallstatt and whether a natural pig breeding monopoly existed during the Hallstatt period^[8]. They raise this as a question for future research, and I treat it as an economic hypothesis. The bones show that Hallstatt obtained pigs from more than one district. That it also influenced how those pigs were bred is a separate hypothesis. A processing centre supplied by several farming districts could have set procurement requirements for its animals. The strong preference for castrated males of one age suggests that it did^[11]. Large buyers create uniformity, because they need predictable animals, cuts and quality. If the needs of Hallstatt shaped the way surrounding farms raised and prepared their pigs, the centre itself would have spread a standard method across a wider farming region.

Did the Processor Shape the Pig?

The animals came from different areas, yet they matched a narrow specification of sex, age and probably castration^{[8, 11]}. A food industry becomes a system when the needs of processing begin to influence the animals supplied to it. At Hallstatt the chain may have run from the demand of the processor to a preferred carcass, to castration and husbandry, to the age of slaughter, to selection by farmers or traders, to the preparation of the carcass and finally to the basins. This hypothesis can be tested. If Hallstatt exerted such pressure, contemporary settlements in its supply areas should show pig husbandry directed towards castrated males killed at the Hallstatt age.

Castration may also have served the supply chain. Entire boars are more aggressive than castrated males^[20], and Hallstatt needed animals or carcasses to move from several districts to one centre. Castration could therefore have improved temperament, meat quality, fat cover and management at the same time. A specialised supply chain prefers an animal that is predictable both alive and dead. No source shows that transport was the reason for castration, but the combination should be studied.

Anatomy and Learned Procedure

The anatomy of the pig limits the number of sensible ways to use it. Every pig has legs, shoulders, a neck, a back with fat, a belly, a head, offal, blood and intestines, and some similarity between European traditions follows from this alone. A leg becomes a ham partly because of its shape and size. However, the choice of a slaughter age, a way of dividing the carcass, the order and length of salting, the place of ageing and the season of production carries much more information. People learn these choices and pass them on. At Hallstatt, thousands of pig bones show the same cutting technique^[8], which Barth describes as an old method of cutting up pigs^[14]. A cutting method of this kind is learned procedure, and it can be taught from one generation to the next.

Hallstatt and Gailtaler Speck

The Hallstatt cutting method has a modern parallel in Carinthia. The museum writes that the prehistoric technique was very different from the methods commonly used today, but that it is still employed in a few regions of the Eastern Alps. In the production of Gailtaler Speck the pig is also deboned from the back with the ribs and the entrails, from the tail to the skull, and the two boneless halves are then salted and smoked^[12]. A caption by Barth on the same page names Kaning near Radenthein in Carinthia as a place where the method reconstructed for Bronze Age Hallstatt is used today^[12].

The protected geographical indication describes the modern product. Gailtaler Speck is a raw cured product of unpressed, boneless pork. It can be made from whole sides or from belly, loin, ham and shoulder^{[34, 36]}. The pieces are dry cured unpressed at no more than 10 °C for one to four weeks, depending on their thickness. They are cold smoked at 8 to 24 °C over beech wood with juniper, and they mature for at least four to twelve weeks, a whole side for at least twelve weeks^{[34, 36]}. The ministry records Speck production in the Gailtal from the 15th century onwards, for example in the travel diaries of Paolo Santonino from 1485 to 1487^[36]. The specification itself refers to half carcasses that the producer cuts and debones, and it does not describe the opening from the back^[34]. The parallel in butchery therefore rests on the statement of the museum.

The two systems can be compared step by step. At Hallstatt, selected pigs arrived as partly deboned sections, were salted in Haselgebirge, according to the reconstruction for seven to ten days, and matured in the cold moving air of the mine^{[11, 12, 13]}. In the Gailtal, boneless sides or cuts are dry salted for one to four weeks, cold smoked on purpose and matured in a ventilated room^[34]. The resemblance extends to the procedure of carcass division and not only to the finished product. No source proves an unbroken tradition over 3,000 years, and the comparison does not need one. Salted pork is easy to reinvent, but the same unusual way of opening the carcass, in the same Alpine region, is much less likely to have been reinvented independently. Cultural retention over a very long period is therefore a serious hypothesis. It shows that a specific method seen in the Bronze Age bones is still a working method in the same mountains.

The method may also have technical advantages. Removing the spine and ribs changes the shape of the carcass. It exposes more muscle surface to salt, reduces the weight that has to be carried and may shorten the distance over which salt must travel into the meat. These advantages are plausible but untested. An experiment that salts and dries whole carcasses, carcasses opened from the back as in the Gailtal and fully deboned sides or muscles would show whether the method gives measurable advantages. It should measure the carrying mass, the shape of the load, the number of carriers, the distance, the depth of salt penetration, the exposed surface, the loss of liquid, the rate of drying, the stability of the pieces when hung and the yield after maturation. The result would show whether the Hallstatt method was a cultural tradition, a technical optimum, or both.

Hallstatt and the Celts

Archaeologists use the name Hallstatt culture for the culture of central and western Europe in the Late Bronze Age and the Early Iron Age^[37]. The famous cemetery at Hallstatt belongs to the Early Iron Age^[9]. So does the second period of mining, which lasted from the 9th century BCE until about the middle of the 4th century BCE^{[18, 19]}. Scholars of the 19th century already regarded Hallstatt as a Celtic site^[38], and the basins were once dated to a Celtic period^[10]. Radiocarbon dating placed them in the Bronze Age, several centuries before Herodotus wrote about the Keltoi in the 5th century BCE^{[10, 38]}. Nobody called the salters of the basins Celts. They worked, however, in the same mountains and the same salt as the later people whom Greek and Roman writers called Celts, and their knowledge could have passed to them.

1. About 1500 BCE. Underground salt mining is attested at Hallstatt^[8].
2. 5th century BCE. Herodotus writes of the Keltoi^[38].
3. About 160 BCE. Cato records the salting of hams^{[27, 32]}.
4. 1st century BCE. Varro praises the flitches and hams of Gaul^[32].
5. Early 1st century CE. Strabo reports Gaulish salt pork at Rome^[33].

The evidence on one time scale. The basins and the Iron Age mine are shown as bars^{[10, 18, 19]}, and the numbers mark the events listed above.

What Roman Writers Say

Written evidence for salted pork begins late. Cato described how to salt hams in De Agri Cultura (On Farming), which he wrote about 160 BCE. The hams were packed in salt in a jar, restacked after five days and taken out after twelve. Then they were brushed, hung, oiled and smoked^{[27, 32]}. The seven to ten days of the Hallstatt reconstruction are close to Cato’s figure^[13], although Hallstatt is about a thousand years older. Equal days do not mean equal salt content, however. Salt uptake depends on the weight of the piece, its fat cover, the temperature and the time. Ham makers today still salt for about one day per kilogram of green ham, and lean hams take up salt faster than fat ones^{[28, 39]}. The similarity in days therefore shows a similar practice, but not necessarily the same final salt concentration.

Roman writers say that the Gauls made the best salted pork. Varro wrote in the 1st century BCE that “the Gauls usually make the best and largest flitches”, and that Comacine and Cavarine hams and shoulders were still imported every year from Gaul to Rome^[32]. He also quotes Cato, who wrote that “the Insubrians in Italy salt down three and four thousand flitches”^[32], so Varro uses the Insubrians of Italy as his example of Gallic flitches^[32]. Strabo wrote in the early 1st century CE that the Gauls ate pork “both fresh and salted”. Their herds supplied salted meat to Rome and to most of Italy, and the country of the Sequani sent the best salted pork to Rome^[33]. A review of the ancient and Byzantine sources shows that bacon was important in the diet of Gaul^[40]. In Roman times, therefore, salted pork was a known speciality of Gaul and of the Gaulish north of Italy.

From the Hallstatt Salters to the Celts

The linguist Wolfgang Meid wrote that the Celts “had perhaps some share in the Urnfield and Hillfort culture of the second millennium BC” and a larger share in the Hallstatt culture of about 800 to 400 BCE, especially in its western part. He regarded the La Tène civilisation, from 400 BCE onwards, as “definitely Celtic in character”^[41]. On this view the Bronze Age salters of Hallstatt belong to the background of the Celts, and the Iron Age miners of Hallstatt to their early history. Patrick Sims-Williams warns that “Celtic” is “rightly regarded as a misleading label for the central European Hallstatt and La Tène material ‘cultures’ of the Late Bronze Age and Iron Age”, and he places the origin of the Celtic languages further west, in the region of Gaul^[38]. The name is disputed. The region, however, remained a centre of salt and of livestock from the Bronze Age to the Roman period. Iron Age mining at Hallstatt lasted until about the middle of the 4th century BCE^[18], the Celtic salt mine of the Dürrnberg near Hallein was worked in the Iron Age^[42], and mining at Hallstatt began again in the 2nd century BCE^[43].

The mine itself shows a break. The Bronze Age mine closed in the 13th century BCE, and mining started again 300 to 400 years later, in the 9th century BCE, in another part of the mountain and with new methods^{[18, 19]}. This gap shows that salt was not mined at this place for three to four centuries. It does not show that the people of the region stopped salting meat. The animal bones of the Iron Age mine show none of the peculiarities of the Bronze Age assemblage and are interpreted as ordinary food waste^[44]. At the mining sites of the Eastern Alps pigs supplied most of the meat in the Late Bronze Age, while cattle, sheep and goats supplied most of it in the Iron Age^[45]. Basins full of selected castrated pigs therefore did not continue at the Alpine mines, as far as the published bones show.

A break in one installation is not a break in knowledge, and several findings point to continuity of skill. Saliari and colleagues found butchery marks at the Bronze Age mining sites that “evidence a standardized slaughtering process carried out by professional butchers”. Their butchery experiments showed that “similar butchery techniques are employed in the Austrian Alps until today”^[45]. The Hallstatt pigs were opened from the back, as the pigs for Gailtaler Speck are opened in Carinthia today^[12]. Pork also remained part of the diet in the salt mountains. A study of human faeces from the Hallstatt mine found “consumption of cattle (Bos taurus) and swine meats (Sus scrofa) throughout all investigated time periods”, from the Bronze Age to the Baroque^[46]. The Iron Age faeces contained feet and tails of pigs, which Barth reads as the use of inferior parts that were not suitable for ham and bacon^[47]. At the Dürrnberg the faeces of the miners contained pig bristles, skin and rind^[48]. The Natural History Museum in Vienna suggests that cattle were processed at the Dürrnberg for the export of cured meat^[49], while Pucher reads the bones as meat supplied to the miners by nearby settlements^[50].

The pig kept its place in Celtic Europe. Erich Pucher notes that high proportions of pig bones were found again and again at the oppidum of Manching in Bavaria and at the Heuneburg on the upper Danube, a princely seat of the Hallstatt period, and that they count as characteristic of Celtic settlements^[51]. In Gaul pork became a product for trade. At Levroux Les Arènes, a Celtic village of the 2nd century BCE, some of the ham bearing bones are underrepresented, and the excavators suggest that the meat was made into cured pork of high value, which then circulated in the existing trade networks^[52]. Roman writers of the 1st century BCE and the early 1st century CE then name the Gauls, the Sequani and the Gauls of northern Italy as the best producers of salted pork^{[32, 33]}. Athenaeus wrote about 200 CE that the best hams came from Cisalpine Gaul^[53].

The evidence therefore shows a break at the mine and continuity in the region. The basins were abandoned, but the people of the Eastern Alps and of the wider Hallstatt and La Tène world kept pigs, kept professional butchers and kept making salt, and by the 2nd century BCE Celtic villages in Gaul produced pork for trade. Knowledge of this kind is learned by doing and passed from master to apprentice. In my experience such knowledge, once a society has used it on a large scale, is taken up by smaller operations and does not disappear. I therefore consider it likely that the knowledge of the Hallstatt salters survived on farms, at salt works and in households, and that the Celtic salted pork praised in Rome descends in part from it. No excavation has yet traced this line from site to site. The bones of Iron Age farms and settlements in the Alps and in Gaul will either show it or refute it.

Hallstatt Was Not Isolated

Hallstatt was a salt centre, and a salt centre depends on exchange. A mine produces far more salt than its own workers use, and the miners of the Salzbergtal could not raise their own animals. Their pork came from at least two supply areas, and the DNA of the pigs points to large herds or several farms^{[8, 11]}. Hallstatt therefore belonged to regional networks of salt and livestock. Evidence from textiles, crops, bone skates and ancient DNA shows that it also belonged to a much larger system of exchange across Eurasia.

Textiles at Both Ends of Eurasia

The clearest evidence for this larger system comes from textiles and crops, not from meat. At Qizilchoqa near Hami, in the east of the Tarim region of western China, Victor Mair reports plaids in diagonal twill. He dates the site to about 1200 BCE in one publication and the plaids to about 1000 BCE in another, and he compares them with what he calls plaids from Celtic sites in Europe^{[54, 55]}. Elizabeth Barber compares a plaid twill from the Hallstatt salt mine, from the first half of the first millennium BCE, with the twills of the Tarim burials^[56]. Mair also writes that most traffic across the continent in the 2nd and 1st millennia BCE moved from west to east^[54].

Millet from China to the Alps

Movement also went the other way. Broomcorn millet (Panicum miliaceum) was domesticated in northeast China by 6000 BCE. Radiocarbon dates of millet grains from 75 European sites show that people in Europe began to grow it in the 16th century BCE at the earliest, and that it spread quickly in the 15th and 14th centuries BCE^[57]. The miners of Hallstatt ate it. A sample of human faeces from the mine, dated to the Late Bronze Age, consisted almost entirely of cereal remains, and proso millet, which is the same plant as broomcorn millet, was among them^[58]. A weaving technique therefore appears at both ends of Eurasia, and a crop from East Asia reached the Hallstatt miners in the same period.

Bone Skates from Hungary to Xinjiang

Another find comes from the Ili valley in northwestern Xinjiang. At the Gaotai site in Nilka County, archaeologists found ice skates made of cattle and horse bone at a site dated to the 16th and 15th centuries BCE. The Xinjiang archaeologists reported that the form of the skates is almost identical to early bone skates from Europe, and that the find gives new evidence for early exchange across Eurasia^[59]. Ruan Qiurong of the Xinjiang Institute of Cultural Relics and Archaeology described them as “almost exactly the same as ice skates from prehistoric Europe”^[60]. So far the skates have been reported only in the press, and I have not found a full scientific publication.

Hungary has one of the longest series of bone runners in Europe. Alice Choyke and László Bartosiewicz studied runners made from horse bones in prehistoric Hungary^[61]. A summary of their work reports that the oldest runners in Hungary date from the Bell Beaker period, and that one was found at the Middle Bronze Age tell of Százhalombatta-Földvár near Budapest. Makers used the radius of the horse in the Early and Middle Bronze Age and the metapodials of horses and cattle later^[62]. Some archaeologists no longer regard the runners made from the radius as skates, and some of them may have served as runners for sledges^[61]. The town of Százhalombatta takes its name from tumuli of the Hallstatt period, which date from the second half of the 7th century BCE^[63].

In both regions people made runners from the bones of horses and cattle. Gaotai, however, is in the Ili valley and not in Turpan. The skates therefore show the same kind of exchange as the textiles and the millet. They do not show a direct link between Hungary, Hallstatt and Turpan.

Iran Between the Two

The salt mine of Douzlākh at Chehrābād in northwestern Iran is located between the Alps and the Tarim region. Its salt mummies date from about 400 BCE to 600 CE^[64]. They are much later than the Hallstatt basins, so they cannot show a Bronze Age link. However, they show that salt preserved people and their clothing in three regions, namely the Alps, Iran and the Tarim region^{[55, 64, 65]}. Research also connects the sites. Karina Grömer of the Natural History Museum in Vienna is an author of the standard study of the textiles from the Hallstatt salt mines^[66], and she is also an author of a study of the garments of Salt Man 4 from Chehrābād^[67]. The Vienna museum lists this Iranian work among its own textile research^[64].

What Else Moved, and What Did Not

Many other goods and techniques crossed Eurasia in the Bronze Age. Wheat reached the lower Yellow River around 2600 BCE and Gansu and Xinjiang around 1900 BCE, probably through contact with the peoples of the steppe^[68]. Contacts between the Qijia culture of northwestern China and the Seima-Turbino bronze tradition date from 2200 to 2000 BCE, and they are linked with the beginning of metallurgy in China^[69]. The domestic horse spread from the lower Volga and Don region across Eurasia from about 2000 BCE, together with chariots with spoked wheels^[70]. The chicken moved in the opposite direction. The oldest certain bones of domestic chickens come from Ban Non Wat in Thailand, about 1650 to 1250 BCE, and chickens reached Mediterranean Europe by about 800 BCE^[71]. In Europe they were at first exotic birds and were eaten only centuries later^[72].

Food technology moved as well. The people buried at Xiaohe in the Tarim Basin, around 1900 to 1700 BCE, made cheese with a kefir culture of bacteria and yeast and not with rennet^{[73, 74]}. A study of this cheese in 2024 found that the kefir bacteria spread from Xinjiang into inland East Asia^[75]. At Yanghai near Turpan, people of the late 2nd millennium BCE wore trousers^[76], woven largely in an elastic twill^[77].

Silk is a different case. Silk threads were once reported from princely graves of the Hallstatt period in southwestern Germany and from the Kerameikos in Athens. Irene Good pointed out that a silk fibre need not come from China, and her amino acid analyses indicated wild silk^[78]. Lise Bender Jørgensen concluded in 2013 that “none of the claimed Iron Age silks can be confirmed” and that silk traffic to Europe before the Roman period “cannot be substantiated”^[79]. Exchange was therefore selective. Crops, animals, metals, dairy cultures and weaving methods moved, while no Chinese silk of this period has been confirmed in Europe.

Techniques Moved Without Whole Populations

The genetic evidence from the Tarim region shows how such exchange worked. The earliest Tarim mummies, dated to about 2100 to 1700 BCE, belonged to a genetically isolated local population. Yet these people adopted the farming and herding practices of their neighbours^[73]. Techniques and crops crossed Eurasia in both directions, even where whole populations did not move. I make the same point in Pressed Meat: A Chinese Technology Set. People at salt centres and on the routes between them had good reason to look for useful goods and methods from far away, much as traders and entrepreneurs do today. This answers an objection to a Hallstatt origin. A technique from Hallstatt did not need people from Hallstatt to carry it to Gaul or Britain, because it could pass from one community to the next, as weaving methods and crops did.

The Same Centuries

These events belong to the same few centuries of the Late Bronze Age. The Hallstatt basins date from the 13th and 12th centuries BCE^[10]. Millet spread through Europe in the 15th and 14th centuries BCE, and the Bronze Age miners ate it^{[57, 58]}. The bone skates of Gaotai date from the 16th and 15th centuries BCE^[59], and the twill plaids of Qizilchoqa from about 1200 to 1000 BCE^{[54, 55]}. Many people moved from the continent to Britain between 1300 and 800 BCE^[80]. These dates are not separated by thousands of years, and the meat industry of Hallstatt operated while crops, weaving methods and people were moving over long distances.

Hallstatt obtained pigs from surrounding farming districts and produced salt and preserved meat within a regional trading economy. Salt production, pigs brought from outside, a standard way of cutting and preservation on a large scale came together there^{[8, 10, 11, 13]}. The archaeological and genetic evidence shows wide interaction across Bronze Age Eurasia, and Hallstatt took part in regional exchange within this connected world. The evidence does not show direct trade between Hallstatt and every region named here, and it does not show that pork curing travelled between Hallstatt and western China.

Older Than the Silk Road

The name Silk Road is modern. Ferdinand von Richthofen coined the word Seidenstraße in 1877^[81]. The Han emperor Wudi sent Zhang Qian to the west in 138 BCE, and his mission opened the official Han routes to Central Asia^[82]. The routes themselves are much older. Michael Frachetti and colleagues found that herders used the mountain routes of Inner Asia as early as 2500 BCE, and they conclude that “the foundational circuitry of vast trans-Asian networks likely emerged millennia before” the written sources on trade^[83]. The contacts between the Alps and the Tarim region described above belong to this older network, about a thousand years before Zhang Qian. In the Iron Age, Hallstatt was rich enough to draw goods from far away. Its graves contain ivory that probably came from Africa, glass from the head of the Adriatic, amber inlays and Greek vessels for wine^[84]. Silk, however, has not been confirmed in the graves of the Hallstatt period^[79].

What the Corridor Teaches

Millet, textiles and bone skates do not prove that ham technology moved. They show that Bronze Age Eurasia could carry specific crops, animals, materials and practices across very great distances in the centuries when the Hallstatt basins were in use. Practical techniques crossed Eurasia from one community to the next, without whole populations moving^[73]. The exchange was selective, because crops, horses, chickens, metals and dairy cultures moved while silk did not^{[68, 70, 71, 79]}. The pigs at each end were of local descent, as a later section shows^{[8, 85]}. Salt, water and muscle protein behave the same way everywhere, so people at both ends faced the same physical problems. Knowledge of the solutions could move along the same routes as weaving and cheese making. Millet, horses and chickens moved as living things, and they show that the regions were connected. Twill weaving is different, because it is a learned manufacturing procedure, and the textiles show that a skilled procedure was transmitted. Pigs largely reproduced locally. Curing knowledge, if it moved, belongs with weaving and not with millet, so the textiles are the closest analogy for the history of curing.

Where It Began, How It Spread, Why It Lasted

The history has three parts. The first is where the system first took shape. The second is how knowledge of it moved between communities. The third is how institutions repeated the practice until it became normal in a culture.

Hallstatt is the earliest documented mature form of the organised pork curing system examined here. Its scale and organisation make it a credible centre from which established practices could have spread^{[8, 10, 14]}. The documented movement of crops, techniques and people in the Late Bronze Age provides a credible means of diffusion^{[57, 58, 80, 86]}. A method spreads when it gives results that people want, is useful to the economy, can be shown to others and can be repeated with the resources available. Salting pork met all four conditions. Institutions then repeated and fixed the practice in a chain. Gaul shows regional specialisation^{[32, 33]}, although Gaul need not have learned its methods directly from Hallstatt. Its development is better seen as regional growth within connected European societies. Rome turned regional specialities into goods traded between regions, with named hams, fixed prices and army rations^{[87, 88]}. Rome did not invent the technology, but its roads, armies, towns, markets, taxes and trade increased the speed at which products and practices moved between regions, and Rome provides the strongest documented institutional mechanism by which continental curing practices could be amplified and reproduced in Britain. Rome did not need to make every region identical. It increased the pressure towards products that could be moved, measured and traded, and this is why the written record becomes much clearer in Roman times. The Carolingian estates made the practice part of administration^[89]. Guilds and apprenticeship preserved and refined professional knowledge^[90]. Industry and meat science standardised it further in the 19th and 20th centuries^{[24, 26, 91]}. Hallstatt does not have to explain why an Austrian butcher and an English butcher did related work 2,000 years later. It may explain the early system, while the later institutions explain why it lasted and became more uniform. The precise routes of diffusion cannot be shown with the evidence available today. The next sections therefore concentrate on the positive evidence for how the practice spread and why it lasted.

The movement of technology did not require the movement of specialist butchers alone. The product could carry information about the process. A cured side or ham showed how the carcass had been divided, which bones had been removed, how much fat had been left, whether the surface had dried or been exposed to smoke, and how the piece had been prepared for hanging. A butcher who received it could copy it. Technology can therefore spread in four ways. People move, craftsmen teach, products move and are copied, and producing and consuming regions trade with each other again and again. The commodity was also a demonstration of the method.

Hallstatt did not need a separate network for cured meat. Salt had to leave the mountain and reach farming communities, while pigs and other provisions moved towards it^{[8, 11, 31]}. If preserved pork entered exchange, it could move through this existing traffic. The same traders, routes, pack animals, river valleys and markets that distributed Hallstatt salt could also carry preserved meat and knowledge of how it was made. The directions of movement are revealing. Farming regions sent living animals inward, the mine added preservation, and stable goods moved outward. Hallstatt stood at the point of conversion, and knowledge of curing could travel with the commodity.

The whole history can be summarised in six linked stages. The ecology and husbandry of the pig created a seasonal surplus. At Hallstatt older practices combined into specialised production. Exchange across Europe carried procedures and products. Regional climate and ecology differentiated local styles. Rome and later institutions spread and standardised the practice. Modern science finally explained and tightened processes that craftsmen already understood by practice.

Invention and Combination

The historical importance of Hallstatt does not depend on whether someone there was the first person in Europe to put salt on pork. Technologies often arise by combining older practices. Salt, pigs, winter slaughter and drying all existed before. At Hallstatt they had combined by the 13th and 12th centuries BCE into a specialised system with selected animals, standard butchery, purpose built salting installations, large batches, cold maturation, the use of secondary products and probable surplus^{[8, 10, 11, 12, 13, 14]}. Hallstatt is therefore at present the earliest archaeological demonstration in Europe not of pork salting itself, but of a pork curing industry.

Three meanings of origin must be kept apart. The first is the origin of the principle, when someone discovered that salt preserves pork. The second is the origin of the technological system, when selection, standard butchery, salt, specialised installations, maturation, the use of secondary products and organised supply were integrated. The third is the origin of particular products such as Parma ham, Bayonne ham, Wiltshire bacon, Gailtaler Speck or the Krainer, which appeared much later. Hallstatt is not shown to be the first. It is at present the earliest demonstrated system of the second kind. Whether it was also an ancestral system of later European curing is a historical hypothesis. It is not the origin of the third. The map shows the places discussed in this article.

1. Hallstatt. Curing basins of the 13th and 12th centuries BCE and salt mining^{[8, 10, 12]}
2. Dürrnberg near Hallein. Salt mining from the 6th century BCE^[92]
3. Seille valley, Lorraine. Salt works from the 8th to 6th century BCE onwards^[93]
4. Acy-Romance. Pork prepared for salting, 2nd and 1st centuries BCE^[94]
5. Kerobestin and Douarnenez, Brittany. Roman salting vats used for beef and mutton^[95]
6. Iulia Traducta (Algeciras). Vats used for salting meat in the early 6th century CE^[95]
7. Villafáfila salt lakes. Salt extraction with Beaker pottery, second half of the 3rd millennium BCE^[96]
8. Street House, Loftus. Salt making, 3800 to 3700 BCE^[97]
9. Droitwich. Salt production from the Iron Age to the 19th century^[98]
10. West Mersea, Essex. Late Iron Age and Roman salterns^[99]
11. Durrington Walls. Pigs brought from across Britain and killed mainly in winter^{[100, 101]}
12. Vindolanda. Bacon in the fort accounts, 104 to 120 CE^[87]
13. Insubres, Po plain. Flitches salted by the thousand, according to Cato as quoted by Varro^[32]
14. Sequani, region of Besançon. The best salted pork sent to Rome, according to Strabo^[33]
15. Százhalombatta-Földvár. Bone runners of the Middle Bronze Age^{[61, 62]}
16. Poiana Slatinei. Salt spring used from 6050 to 5500 BCE^[6]
17. Kaning near Radenthein, Carinthia. The Hallstatt cutting method still in use^[12]

Salt, pork processing and contact in Europe. Positions are approximate, and the dates of the sites differ widely, as the key shows. The arrow marks the migration from the continent to Britain between 1300 and 800 BCE shown by ancient DNA^[80]. The Tarim region and Gaotai lie far to the east and are not shown.

How Salted Pork Spread in Europe

The exchange across Eurasia shows how knowledge could move. Within Europe, four main influences spread salt making and salted pork, and the time scale below shows them together.

1. 6050 to 5500 BCE. Salt spring of Poiana Slatinei, Romania^[6].
2. 3800 to 3700 BCE. Saltern at Street House, England^[97].
3. 2500 to 2000 BCE. Beaker salt works of Molino Sanchón II, Spain^[96].
4. 8th to 6th century BCE. Oldest dated salt works of the Seille valley, France^[93].
5. 13th to 12th century BCE. Curing basins of Hallstatt^[10].
6. About 160 BCE. Cato records the salting of hams^{[27, 32]}.
7. 104 to 120 CE. Bacon in the accounts of Vindolanda, Britain^[87].
8. 2750 to 1800 BCE. Bell Beaker pottery across western and central Europe^[102].
9. 1300 to 800 BCE. Migration from the continent into Britain^[80], in the centuries of the Urnfield culture^[86].

Salt making, salted pork and contact between regions, by date. Hallstatt (5) is the only site where curing installations for meat have been excavated.

Neolithic Salt Making

Salt making spread through Europe in the Neolithic. Poiana Slatinei in Romania dates to 6050 to 5500 BCE^[6], and Harding lists further Neolithic briquetage from Cacica in Romania, the Wieliczka area in Poland and Provadia in Bulgaria^[103]. The technique reached Britain early. At Street House near Loftus in north east England, Stephen Sherlock excavated a pit for storing brine and a saltern with at least three hearths, dated to 3800 to 3700 BCE^[97]. Ethnographic studies show that salt is very often used to preserve meat and cheese^[103]. However, no find connects the Neolithic salt of these sites with meat. This period shows that people could make salt, but not that they salted meat.

Bell Beakers, Pigs and the Word for Salt

Between about 2750 and 2500 BCE, Bell Beaker pottery spread across western and central Europe. In Britain its arrival coincided with the replacement of about 90 per cent of the gene pool within a few hundred years^[102]. Iberia, central Europe and Britain now shared one pottery style, and salt making was part of this culture. At Molino Sanchón II on the salt lakes of Villafáfila in north west Spain, people extracted salt in the second half of the third millennium BCE and left large amounts of decorated Beaker pottery there^[96].

In Britain, pigs were already moved over long distances at this time. Isotope analysis of 131 pigs from four henge sites in southern Britain, dated to about 2800 to 2400 BCE, showed that the pigs came from all over Britain and that few were raised locally^[100]. Hallstatt also obtained its pigs from outside, and Britain had a similar supply system more than a thousand years earlier. However, nothing shows that the pork at the henges was salted.

Language provides further evidence. The word for salt, reconstructed as *sal-, is shared by the Celtic, Italic, Germanic, Baltic, Slavic, Greek, Armenian and Tocharian languages, but not by the Indo-Iranian languages^{[104, 105]}. Old Irish, Welsh, Latin and Gothic therefore inherited the same word, which is older than Celtic as a separate language.

The Late Bronze Age

At the time of the Hallstatt basins, one culture spread across much of Europe. Urn cemeteries first appeared in east central Europe and northern Italy, and from the 12th century BCE they spread to Ukraine, Sicily and Scandinavia, and through France to the Iberian peninsula^[86]. Archaeologists call this the Urnfield culture, and it strongly influenced the Early Iron Age^[86]. At the mines of the Eastern Alps, pigs supplied most of the meat in this period^[45].

Britain was connected to this world. Ancient DNA shows that many people moved from the continent to Britain between 1300 and 800 BCE. They were most similar to ancient people from France, and they provided about half the ancestry of the Iron Age people of England and Wales^[80]. The authors call this migration “a plausible vector for the spread of early Celtic languages into Britain”^[80].

The Late Bronze Age therefore had a meat industry at Hallstatt^{[8, 10, 14]}, a culture that spread across the continent^[86] and a proven movement of people to Britain^[80]. It is consequently the strongest candidate for the period in which an established technology of salted pork began to circulate widely in Europe. This does not mean that people invented salting everywhere at once.

The Celtic question also appears in a different light. Sims-Williams argues that early Celtic spread from the region of Gaul^[38], and Patterson and colleagues suggest that it reached Britain in the Late Bronze Age^[80]. If both are right, the first speakers of Celtic lived at the same time as the Hallstatt salters.

Between Hallstatt and Acy-Romance

The published animal bones from the thousand years between the two sites do not yet show a continuous trail, and in the Alps they point the other way. Pucher finds no evidence at present for a concentration on the pig in the Iron Age^[14]. At the Alpine mining sites pigs supplied most of the meat in the Late Bronze Age, but cattle, sheep and goats replaced them in the Iron Age^[45]. At the Dürrnberg, cattle make up 78 per cent of the identified bones. Pigs are weakly represented, and the meat poor lower limbs are largely missing, which suggests to Pucher that only pork and not live pigs reached the Dürrnberg^[14]. Among these pigs, however, females outnumbered males, the opposite of Hallstatt^[14]. The salting of meat for trade at the Dürrnberg has been argued for cattle, whose best parts are underrepresented in the bones^[42].

Hallstatt itself gives one hint of continuity. Human faeces from the Early Iron Age eastern mine contained feet and tails of pig and of sheep or goat, and Barth reads this as the use of inferior parts that were not suitable for ham and bacon^[47]. In Gaul, specialised pig production appears later. At Levroux, isotope and size studies point to selection for size and weight in a specialised production of pork, with changes from the late 3rd century BCE^{[52, 106]}. At Entremont in Provence, in the 2nd century BCE, the hind limbs of pigs are more frequent than the fore limbs, which raises the possibility that hams were brought in^[107]. The Bronze Age concentration on castrated male pigs therefore did not continue at the Alpine salt mines in the Iron Age, as far as the published bones show. If knowledge of curing passed from the Bronze Age to Iron Age Gaul, it passed through farms and households that have not yet been studied for this purpose. Several key reports on the Iron Age bones of Hallstatt and the Dürrnberg have still to be checked.

Pork Salting in Iron Age Gaul. Acy-Romance

The Gaulish village of Acy-Romance near Reims, in the Ardennes, was occupied in the 2nd and 1st centuries BCE^[108]. It was excavated over many seasons under Bernard Lambot^[109], and Patrice Méniel studied more than 200,000 animal bones from the site^{[108, 110]}. Some pigs were roasted on the spit, while others were cut up and their meat was salted. The rubbish pits show that the trotters and backbones were always thrown away before the heads and limbs, which were probably kept for a while for curing^[94]. In the graves, the offerings of food were generally quarters of pork, arranged in such a way as to suggest an entire animal^[111]. The graves show that the division of the pig into quarters also had a social and ritual meaning, but they do not show that these offerings were salted. The village was occupied in the century in which Varro praised the flitches and hams of Gaul^[32].

Acy-Romance and Hallstatt were different kinds of place. Hallstatt was a processing centre with curing basins, supplied with pigs from outside. Acy-Romance was a village that raised, ate and preserved its own pigs. At Hallstatt the spine and ribs were removed at slaughter, so the bones of the trunk are largely missing from the finds^[11]. At Acy-Romance the trotters and backbones were discarded first and the heads and limbs were kept^[94]. The operations are not identical, and no direct line connects the two sites. Both, however, show that people selected particular parts of the carcass for preservation, about a thousand years apart.

Reading Missing Bones

Preserved meat rarely survives in the ground. The decisions of the butcher may survive instead as missing bones. If the same parts of the skeleton repeatedly disappear from an assemblage, while other parts accumulate, the absence itself records how the carcass was divided. Hallstatt is the best example. The missing bones of the trunk show that the carcass had already been opened and partly deboned before it reached the Salzbergtal^[11]. At Acy-Romance the pattern is different, but the order in which bones entered the rubbish pits again records the selection of portions for curing^[94]. The product that the butcher wanted to make determined which bones were left behind.

Hallstatt also shows two stages of processing. Slaughter and the first dressing took place outside the Salzbergtal, and preservation took place at Hallstatt, so that Hallstatt received an intermediate product^{[11, 12]}. The removal was selective. The spine, ribs and entrails were taken out before the climb, while the long bones mostly stayed in until the meat reached the mountain^{[11, 12]}. The butchers may have balanced the weight to be carried against the stability of the carcass, the ease of carrying, the protection of the muscle and the needs of later processing. An experiment on carcass preparation should therefore also measure the effort of transport. The missing trunk bones must have gone somewhere. If the supplying settlements are found, their assemblages should contain an excess of exactly the bones that are missing at Hallstatt. The two assemblages should fit together, and such complementary assemblages would allow the supply chain to be reconstructed on the map.

If the only aim had been to reduce weight, all the bones would have been removed. They were not, so the pattern suggests a balance and not the greatest possible deboning. Keeping the long bones may have helped with carrying or hanging, held the muscles together, prevented deformation or protected the meat, and the evidence does not show which. The partly deboned carcass was therefore not merely an animal from which unwanted bones had been taken out. Its consistent form suggests an intermediate product designed for the next stages of transport, salting and maturation. Primary slaughter and dressing took place elsewhere, while secondary butchery, salting and maturation took place at Hallstatt. The supply chain was divided not merely between farming and processing, but between successive processing operations at different places. Hallstatt received neither live pigs nor finished meat. The chain had separate stages. Slaughter, gutting and the removal of the spine and ribs came first. Salting followed in the basins, then maturation and drying in the mine. Bones and brine went to jelly and extract, and the product went to local consumption and probably to exchange^{[11, 12, 13, 14]}.

A candidate supply settlement should therefore not merely contain pigs of the right date and type. Its animal bones should be enriched in exactly the parts that are systematically missing at Hallstatt. This prediction could fail. It becomes stronger when several methods are combined. Radiocarbon dating, strontium and oxygen isotopes, ancient DNA, the age and sex profile, butchery marks and the complementary representation of the skeleton could together identify an actual supply district. Ancient DNA shows biological relationships, while isotopes can point to geographical origin and husbandry. Only the combination of these methods can turn the two probable supply directions into a geography of procurement^[8].

The search for curing therefore need not begin only with basins, salt and smokehouses. It can also begin with the question of what carcass the butcher was trying to make. A curing tradition can survive archaeologically as a systematic subtraction from the skeleton, even when the wooden tubs, the salt and the meat have vanished. The history of European pork curing may be recoverable in part from repeated patterns of skeletal absence in bones that have already been excavated.

Iron Age Salt Works, Gaul and Rome

In the Iron Age, salt was produced on an industrial scale. In the Seille valley in Lorraine, people made salt for more than 500 years. The oldest remains date from the 8th to the 6th century BCE. The waste of fired clay covers more than 10 km, and some heaps are still 12 m high^[93]. Harding notes that briquetage is especially common in France, eastern Britain and the coastal Low Countries^[103]. The Gaulish flitches that Varro praises needed salt on this scale, but no excavation has yet connected a salt works with a store of pork.

Salted pork was not only a Celtic product. Strabo praises the hams of the Carretanians of the Pyrenees, whom he counts among “the Iberian stock”, and he says that their hams rival those of Cantabria^[112]. Rome then supplied its army with the product. A wooden writing tablet from the fort of Vindolanda in northern Britain, written between 104 and 120 CE, records 45 pounds of bacon and 15½ pounds of bacon lard^[87].

Ireland was outside the Roman Empire, but the Irish also salted meat. In early medieval Ireland (c. 400 to 1100 CE), flitches of bacon were a common form of rent paid in food. A law text required a prosperous farmer to keep a sack of sea ash for salting joints of beef^[113]. No salt works of that period has yet been found in Ireland^[113].

Testing the Explanation

Hallstatt remains exceptional, because its wooden installations and animal bones allow the reconstruction of a specialised pork curing operation. Evidence from Iron Age Gaul, including Acy-Romance, also shows the preparation of selected pork portions for salting, although the installations and the curing procedure are less well preserved there^[94]. For many other places I combine the evidence of salt, pigs and contact, and from it I infer the practice. Three kinds of evidence can test this. Bone assemblages from the salt works of Lorraine and eastern Britain should contain pork from animals of the same age that were cut in the same way. Basins like those at Hallstatt should be found at other salt sites of the Late Bronze Age. The Dürrnberg near Hallein is useful for comparison, because Pucher has already compared its meat supply with that of Hallstatt^[8]. However, organised salt mining there began only in the first half of the 6th century BCE, so the Dürrnberg shows the later development of Alpine salt economies and not a contemporary of the Bronze Age basins^[92]. Nuclear DNA from the Hallstatt pigs, which Hammer and colleagues name as the next step^[8], can be compared with DNA from pigs of France and Britain. Pig DNA can show the movement of animals and the history of husbandry, but it cannot show the movement of curing knowledge. Butchery marks, the distribution of carcass parts and processing installations are more direct evidence for that. Bone assemblages should therefore be searched for the same division from the back that the Hallstatt bones show, beginning with Acy-Romance, where the published excavation reports on the animal bones should give the age, sex and anatomical distribution of the pigs^[108]. British assemblages should then be compared with those of Gaul for repeated removal of vertebrae and keeping of limbs. If these tests find nothing, the explanation is weakened.

The period between Hallstatt and Acy-Romance, from about 1200 to 200 BCE, is the largest gap. Published reports on animal bones from Austria, Bavaria, Bohemia, Switzerland, Lorraine, Alsace, Burgundy, northern Italy, the upper Danube and the valleys of the Rhône and Saône should be searched, especially at settlements linked with salt production, mining, exchange routes or an unusually high consumption of pork. They should be searched for the unusual absence or overrepresentation of vertebrae, ribs, mandibles, lower limbs, hams and shoulders, for narrow slaughter ages and for castrated males. The evidence for the spread of curing may already lie in boxes of excavated animal bones. Several further questions follow from the evidence. What share of the Hallstatt meat fed the miners, and what share entered regional trade? Can isotope analysis and more ancient DNA locate the farms that supplied the pigs? Are there comparable curing installations at other Alpine salt centres? Can detailed anatomical comparison document the similarities between Bronze Age butchery and traditional Alpine methods? Where was Hallstatt salt distributed in the Late Bronze Age? Did processing meat at the mine create more value than selling the salt alone, once transport costs, meat yield and losses are counted? How did slaughter age, castration and feeding on mast affect the fatness of the carcass, and therefore the curing method?

Britain

The British evidence forms a sequence of its own. What needs explaining is not whether Hallstatt taught Britain to preserve pork, but when British preservation came to follow the same common method as the continent. This may have happened through Bronze Age contact, may have been reinforced by the later migration and was reinforced again under Rome. Britain had several conditions for salted pork long before Hallstatt. Three questions follow. What knowledge of preservation existed before the Roman occupation? What did continental contact introduce or reinforce? What did Roman institutions later standardise? Salt production alone does not show an established commercial bacon industry before Rome.

Salt making began early. At Street House in north east England, salt was produced between 3800 and 3700 BCE^[97]. Pigs were moved over long distances. Isotope analysis shows that pigs eaten at the henges of southern Britain between about 2800 and 2400 BCE came from all over Britain^[100]. Pigs were slaughtered by season. At Durrington Walls, with a modelled date of 2515 to 2470 cal BCE, younger pigs were brought to the site for feasts held mainly in winter, and older pigs, mainly in their second year, were also killed mostly in winter^[101]. Salt production continued. Briquetage salt production in Britain is firmly dated to the Middle Bronze Age, in the coastal regions of Essex, along the south coast and at the salt springs of Droitwich, with salt also distributed from Cheshire^[114].

Britain therefore already had salt, pigs moved over long distances and winter slaughter. Between 1300 and 800 BCE, during and after the time of the Hallstatt basins, substantial continental ancestry entered Britain^[80]. What the networks of the Late Bronze Age could have introduced or reinforced was an organised procedure for turning these resources into standardised salted pork. This includes how to divide the carcass, which pieces to keep, how much salt to use, how long to leave the meat in salt and how to age it in the cold. This remains a hypothesis, because no excavation in Britain has yet shown it.

Droitwich is the closest British comparison with Hallstatt. Historic England records salt production there from the Iron Age until the 19th century, with wells, timber lined brine tanks, hearths for boiling brine, drying kilns and wooden structures. The town bought the production monopoly from King John, and production reached 1,500 tons by 1400^[98]. Both places had concentrated salt resources and supplied wider regions. However, Hallstatt has direct evidence for the curing of pork, while the evidence at Droitwich concerns the production of salt.

Coastal salt making grew in the Late Iron Age. Historic England notes that the number of salterns rose at that time, which is thought to indicate a rise in population and the development of trade. Some techniques of the Late Iron Age and Roman periods continued earlier methods, and some native innovations appeared in the 1st century BCE. Society in the early Roman period would have demanded more salted meat and fish, which were traded widely^[99]. Rome therefore did not bring a foreign preservation technology to an empty country. It enlarged the market for an established British salt industry. The army then brought bacon to Vindolanda^[87], the Domesday survey measured English woodland by the pigs it could feed^[115], and the bacon curing industry of Wiltshire later grew from this base, as I describe in my review of the history of bacon curing^[24].

How Salted Pork Became Established in Europe

Written sources allow us to follow salted pork from Rome to the modern factory. The techniques are old and were used without a break, while most of the named products are recent.

DATE	WRITTEN RECORD
c. 160 BCE	Cato describes the salting of hams[27, 32]
1st century BCE	Varro praises the flitches and hams of Gaul[32]
104 to 120 CE	Bacon in the accounts of Vindolanda, Britain[87]
301 CE	Diocletian’s price edict lists Menapian and Cerritane ham and smoked Lucanian sausage[88]
c. 792 to 800 CE	The Capitulare de villis orders bacon, smoked meat, sausage and partially salted meat[89]
1086	Domesday Book records woodland by the pigs it feeds[115]
Early 14th century	Nuremberg council rule that pork loin is to be chopped into sausages[116, 117]
1404	Casings for bratwurst in an account of the Walpurgis convent, Arnstadt[118]
c. 1700	Saltpetre replaces vegetable dyes for colouring cured meat[24]
1805	Lahner’s Frankfurter, Vienna[119]
c. 1854	Morgan introduces arterial injection of brine[24]
1891	Polenske finds nitrite in nitrate curing brine[26]
1896	The Krainer sausage first named in print[120]
1901	Haldane explains the red colour of salted meat[91]
1912	The oldest printed Krainer recipe[120]
2015	The Krainer protected as a geographical indication[120]

Written records of salted pork in Europe. The techniques appear early, while the named products, the chemistry and the legal protection belong mainly to the 19th and 20th centuries.

What Had to Be in Place

Salted pork became a staple only where several conditions were met. The Iron Age salt works supplied salt in large quantities^{[93, 103]}. Pigs needed forest. Polybius describes the acorn woods of the Po plain^[121], and in 1086 the Domesday survey of England measured woodland by the number of pigs it could feed. A manor such as Mortlake is listed with 55 pigs liable for tax^[115]. The farming year needed a fixed order, and medieval calendars show November as the month for gathering acorns for the pigs and December as the month for killing them^[122]. Some calendars place the killing in November, after the acorns had fattened the pigs^[123]. Institutions such as the army, the large estate and the town needed stores of meat. Finally, the knowledge had to be taught and sometimes written down, and the written record begins with Cato^{[27, 32]}.

These conditions formed an annual cycle. Early domestic pigs were born in a fixed season^[11]. They grew through the summer, fattened on acorns in the autumn, were killed in winter, were salted in the cold season and matured into the spring. The killing age of one and a half to two years at Hallstatt fits this cycle^[11]. Forests produced acorns in autumn, and the pigs fattened on them. Polybius describes the acorn woods that fed the swine of Italy^[121], and medieval calendars show acorns gathered for the pigs in November and the pigs killed in December^[122]. Winter then supplied the cold, salt stabilised the carcass, and air and smoke completed the preservation^[13]. European ham and bacon are in this sense products of the farming year in the temperate forest. Iberia, France, Italy and central Europe shared not only salt, but the pig, temperate woodland and the same agricultural calendar, and this may be one reason why similar traditions appear across them. The technology was synchronised with the agricultural year. The pig reached its finishing condition, the cold season began, the pig was killed, a surplus of fresh meat appeared, salt preserved it and the product matured through winter and spring. Once the practice was built into the calendar in this way, it lasted for a stronger reason than habit alone. Seasonal slaughter creates a concentrated supply of meat at one time of year. Salt and cold separate the time of slaughter from the time of eating and trade, and this separation is the central economic change that curing made possible.

Rome

Rome turned regional skills into a market across the whole empire. In 301 CE Diocletian issued an edict that set maximum prices throughout the empire. It sets the price of salted pork of the best quality at 16 denarii a pound and of Menapian or Cerritane ham of the best quality at 20 denarii a pound. It also lists pork sausage, and smoked Lucanian pork sausage at 16 denarii a pound^[88]. The Menapii lived in northern Gaul and the Cerretani in the Pyrenees^[112], so both hams named in the edict came from the northwestern provinces. The army took bacon to the frontier of Britain^[87].

Roman Meat Salting Beyond the Written Record

Archaeology shows that Roman salting establishments did not salt only fish. Andrew Wilson writes that not every batch salted in such establishments was fish. In Brittany, cow bones in the bottom of salting vats at Kerobestin suggest the salting of quarters of beef, and there is evidence for salted beef and mutton at Douarnenez^[95]. At Iulia Traducta (Algeciras) in southern Spain, some vats were used for salting joints of horse meat, beef and mutton when the factory was abandoned in the early 6th century CE^[95]. Salted meat was exported in some Punic amphorae and may also have been carried in Roman amphorae. Because the salting technology for meat and fish was very similar, and salt was available mainly on the coast, it made sense to use the same installations for both and to salt meat outside the fishing season^[95].

Salt was supplied mostly by private owners. Annalisa Marzano argues that in the late Republic and the first two centuries of the Empire, state ownership of marine salt works was the exception and not the norm. Fish salting workshops occur almost everywhere, which shows that salt could be bought freely in the quantities needed, presumably at a fair price^[124]. The Roman contribution therefore included commercial production, specialised salting installations, the distribution of salt, organised markets and military demand. Commerce and private producers could spread related techniques without central direction of meat processing.

Charlemagne and the Early Medieval Estate

After the fall of Rome, the large estates of the early Middle Ages continued the practice. Charlemagne was king of the Franks from 768, king of the Lombards from 774 and emperor from 800 until his death in 814^[125]. He therefore ruled both the Frankish lands north of the Alps and Lombard Italy. The Capitulare de villis, an ordinance for his royal estates, is usually dated between about 792 and 800 CE, although some editors place it as late as 812, and its only manuscript was written between 825 and 850^{[126, 127, 128]}. It required each steward to report every year at Christmas on the pigs and on the fat, tallow and soap. It orders the greatest care in making “bacon, smoked meat, sausage, partially salted meat”^[89], in Latin lardum, siccamen, sulcia, niusaltus (chapter 34)^[129]. Charlemagne did not invent these products, because Rome had already set prices for them^[88]. The ordinance shows what the king expected on his estates, in most of the region where the products are now most alike. It does not prove that every estate in his realm worked in the same way. Bacon was also used to pay rent, and in early medieval Ireland flitches of bacon were a common food rent^[113]. Britain was not part of his realm, but after the Norman conquest the Domesday survey of 1086 measured English woodland by the number of pigs it could feed^[115].

Towns and Named Products

The towns gave the products their names. In Nuremberg, a council regulation of the early 14th century ordered that “alle sweinen lentpraten sol man in die wurste hacken” (all pork loin is to be chopped into the sausages). The document carries no year, and the director of the Staatsarchiv Nürnberg dates it between 1306 and 1315. The usual date of 1313 comes from the association of producers^{[116, 117]}. In Thuringia, an account of 1404 from the Walpurgis convent at Arnstadt, kept in the State Archives at Rudolstadt, lists casings for bratwurst, “darme czu bratwurstin”^[118].

In the 19th century many of the products that Austrians and Slovenians still eat today appeared. Johann Georg Lahner, a butcher from Upper Franconia, opened a shop in Vienna in 1804, and in 1805 he made the first Viennese Frankfurter there. He used finely chopped pork and beef with bacon, filled the mixture into sheep casings, smoked the sausages lightly and scalded them^[119]. The Krainer sausage (Kranjska klobasa) is first mentioned in German in Katharina Prato’s cookbook Süddeutsche Küche in 1896. The oldest recipe appears in 1912 in Felicita Kalinšek’s Slovenska kuharica, and in 2015 the European Union registered the Krainer as a protected geographical indication^[120].

Science explained curing in the same period. Polenske reported in 1891 that nitrite forms in curing brines made with nitrate^[26], and in 1901 Haldane showed that the red colour of salted meat comes from nitric oxide bound to the meat pigment^[91]. The Krainer of today is made with sodium nitrite^[120].

Old Techniques and New Products

The chronology separates the ancient craft from the modern product names. Dry salting of hams, smoking, pork sausages, regional hams for distant markets, killing pigs in winter and keeping accounts of stores are all recorded between Cato, about 160 BCE, and the Carolingian estates, about 800 CE^{[27, 32, 88, 89]}. Hallstatt is a thousand years older than Cato. The named products, the chemistry and the legal protection, on the other hand, are new. Lahner’s Frankfurter dates from 1805, arterial injection of brine from about 1854, the Krainer from the late 19th century, and the explanation of the cured colour from 1891 to 1901^{[24, 26, 91, 119, 120]}. The many new products of the 19th century were based on a craft that people had written about for about 2,000 years and that archaeology traces back about 3,000 years.

There are gaps in the sources. Between Diocletian and the Carolingian estates there are few written sources, and before the towns of the late Middle Ages people rarely wrote down the names of local products. A product missing from early sources may still be old.

The Celts and Iron

None of the sources I consulted connects iron technology with the salting of meat. The Celtic speaking peoples of Gaul increased the scale. The salt works of the Seille valley produced salt for more than 500 years^[93], and Strabo describes Gaulish herds large enough to supply Rome and most of Italy^[33]. At the Alpine mines, however, pork became less important in the Iron Age^[45].

A Recipe Without Writing

A traditional meat process consists of information. It specifies which animal, of what age, which part of the carcass, how it is cut, how much salt, for how long, in what season, where the meat hangs and when it is ready. None of this requires writing. The repeated cutting pattern on thousands of Hallstatt bones shows that information of this kind was reproduced about a thousand years before Cato wrote down his instructions for salting ham^{[8, 27]}. Medieval apprenticeship shows one way in which such information was passed on^[90]. Continuity of the craft therefore does not depend on a written recipe.

Writing, Oral Tradition and Apprenticeship

Written sources from Cato to the Capitulare de villis record the main features of the craft^{[27, 32, 89]}. However, most knowledge passed directly from person to person. The method of cutting pigs that Barth reconstructed for Bronze Age Hallstatt is still used in Kaning near Radenthein in Carinthia^[12], although no source proves an unbroken tradition between the two. In medieval guilds, training apprentices was the first aim, and an apprentice butcher usually served seven years before he was granted his freedom to trade^[90]. Calendar pictures taught the farming year and the killing of pigs to people who could not read^[122]. Songs and customs of the pig killing also belong to this tradition, but the sources I consulted do not document them. A master can show a cutting method, and an apprentice can repeat it. The same applies to judging when meat has taken enough salt, has dried enough and has matured. This is how practical knowledge survives without written recipes, and it is important here because the oldest written recipe, Cato’s, is about a thousand years younger than the Hallstatt evidence^[27]. People passed the craft on mainly through practice, apprenticeship and pictures, and only occasionally in writing.

Why It Lasted

Once established, the system solved several problems at once. It preserved a large seasonal surplus and made a fat animal storable. It allowed the meat to be transported, and it turned slaughter in winter into food for the rest of the year^{[27, 87, 121]}. It needed simple equipment and used salt and the cold of winter^[13]. It used almost the whole carcass, from the legs and sides to the bones, blood and intestines^{[14, 27, 89]}. A technology that fitted the pig, the climate and the farming year so well did not need constant central control to survive.

Once established, the system became part of husbandry, seasonal slaughter, food preparation and trade. Its practical advantages encouraged people to keep it, while regional producers adapted single operations to new circumstances. Established husbandry, the season of slaughter, the salt supply, smokehouses, cutting methods and apprenticeship all made it easier to continue familiar practice than to replace it. This explains how a system from the Bronze Age or the Iron Age could last while names, states and finally the chemistry of curing changed. It also explains why European products are both very similar and strongly regional. The common technology is old, and the regional differences are younger^{[27, 32, 118, 119, 120]}.

From Industry to Art

At Hallstatt the work was an industry with selected animals, a standard method of cutting and maturation under favourable natural conditions^{[8, 11, 13]}. Rome made the product a commodity, named by its origin and graded by its quality^[88]. The medieval towns regulated the trade through guilds and gave sausages their local names^{[90, 118]}. In the 18th and 19th centuries curing became an art and a science. Cities created large markets for ready products, as Vienna did for Lahner^[119]. Regions and master butchers competed, and their differences became local identities. Frankfurt allowed only pork in its sausage, while Vienna allowed more than one kind of meat, and in 1884 a Frankfurter won a gold medal at an international culinary exhibition^[119]. Saltpetre came into use for colour around 1700, injection of brine around 1854, and chemistry gave producers control over colour, speed and safety^{[24, 26, 91]}. I think the new products grew out of a craft that all these regions shared, because a common standard made it possible for a new product to stand out.

Why Salted Pork and Not Only Salt

Many societies valued salt, traded it and grew rich from it, yet they made no hams, no bacon and no sausages. Something other than salt must therefore explain the European tradition. I set out the explanation below as a hypothesis.

Salt Without Ham in Africa

Africa shows that salt alone does not lead to cured meat. Baleni produced salt for 2,000 years^[4]. Harding describes a method from Niger that resembles briquetage, the European method of boiling down brine in coarse clay vessels. Of this method he writes, “Something very similar occurs in other parts of the world, for instance the Basin of Mexico”^[103]. In 1352 Ibn Battuta reached Taghaza in the Sahara. Salt was dug there in thick slabs, and the houses and mosques were built of salt blocks. Camels carried the slabs south to Walata and Mali, where salt was used, in his words, “as a medium of exchange, just as gold and silver is used”^[130]. Yet the traditional preserved meats described by the FAO for these regions are dried products made from lean beef, goat and lamb^[131].

Africa is not one tradition, however. In West Africa smoked pork is a common product today. It is made from the shoulders, feet, head or offal, hot smoked at about 100 to 120 °C, and slightly salted or unsalted^[132]. The comparison in this article therefore concerns particular societies, mainly the peoples of southern Africa and the salt trade of the Sahara, and not the whole continent.

The Khoikhoi of the Cape are the plainest example. Their usual food was milk. They killed an ox for a feast, and they ate meat “without salt, spices or bread”^[133]. Mentzel wrote in the 1780s that they “may never eat salt, unless they are among the Christians”^[134]. A people can know salt and still not use it the way Europeans did.

Salt, Ash and Smoke in Southern Africa

The sources on the Khoikhoi contradict each other. Sparrman travelled at the Cape in 1775. He wrote that “the Hottentots absolutely detest salt” and that they ate their meat “either fresh, or else dried in the sun”^[135]. Schapera wrote the opposite in 1930. Among the Khoikhoi, he wrote, “the meat is cut into thin strips, which are salted and dried in the air”, and “in this condition, it will last for a considerable time, and can also be eaten raw”^[136]. He added that “the Boer method of making ‘biltong’ is probably derived from this old Hottentot practice”^[136].

Sparrman’s account is 155 years older than Schapera’s. By 1930 the Khoikhoi had lived beside Dutch colonists and their salt for more than 250 years. I therefore think that the salted strips that Schapera describes may have developed after contact with the Dutch, and that Sparrman describes the older practice. This is my interpretation, because Schapera does not date the practice. The other early uses of salt that Schapera reports were ritual. He quotes a report of 1712 that at a burial “a small amount of salt is placed on its chest, to prevent it from decomposing”^[134].

The Bantu speaking peoples of the region show the same pattern. Lichtenstein travelled in southern Africa between 1803 and 1806, and he wrote of the Tswana that “salt properly, they have none; instead of it they make use of natron, or the ash of a certain salt succulent plant”^[134]. Theal records that in 1687 “a thousand pounds of salted and smoked meat” were bought from the people of Natal, the region that later became the Zulu kingdom^[134]. The record does not say who salted the meat or what salt was used. People I interviewed told me about dried meat among the Venda, and about a dried meat that the Ndebele of Zimbabwe call ewomileyo or umhwabha and the Zulu call umqayiba. They also told me that peoples of the northeast rolled meat in ash before they hung it in the sun and wind^[135]. I recorded these oral accounts myself, and they still need to be checked against published ethnography.

One of these accounts describes dried meat that is cooked again and mixed with peanuts^[135]. The peanut comes from South America, and historians of African farming list it among the crops brought from the Americas^[137]. The first reliable record of it in Africa dates from the 1650s, in the region of Congo and Angola^[138]. The dish in its present form is therefore younger than the middle of the 17th century. Africa has its own groundnut, the Bambara groundnut, which is native and probably came from the region of Timbuktu in Mali^[139]. We do not know whether an older form of the dish used it.

In southern Africa people dried meat, smoked it or treated it with ash, and salt was rare, ritual or recent. None of these accounts describes a ham, a side of bacon or a sausage. The herds were cattle, sheep and goats, and their lean meat can be cut thin and dried^[131].

The Pig

Ham and bacon come from the pig. A ham is the leg of a pig, and a flitch is its side. The Greek sausage, the allas, was a pig intestine filled with meat and fat^[27]. Salted pork therefore depends on the pig.

The pig differs from other farm animals in one important way. Cattle, sheep and goats give milk, wool and work while they are alive. At the Bronze Age mines of the Alps, people kept them mainly for these products, and the pig was the main source of meat^{[45, 140]}. Pigs were raised mainly for meat and fat. A breeding sow gives piglets and pigs eat waste, but a pig gives no milk, wool or work, and most of its value comes at once when it is killed. Frank Frost calculates that a pig of eight months can yield up to fifty kilos of meat, fat and other products. He notes that the first person who killed a pig had to “wonder how to save the remainder for another day”, and that hams became “a form of storable wealth”^[27]. A herder who lives on milk can keep his wealth alive, as the Khoikhoi did^[133]. A pig keeper, by contrast, has to kill the animal and then preserve the meat.

In most African regions that had salt, pigs were rare or absent. The history of the domestic pig in Africa is still debated, because there are few archaeological and genetic data^[141]. Herodotus wrote in the 5th century BCE that swine “are held by the Egyptians to be unclean beasts”^[142]. Islam forbids pork (Qur’an 2:173), and in 1352 there were mosques at the salt mine of Taghaza^[130]. On the Nile and on the salt routes of the Sahara, people did not eat pork.

Fat, Winter and Cold

Meat technologists at the Food and Agriculture Organization describe the conditions for drying meat. Warm, dry air with low humidity is best, and in wet weather or a humid climate the meat should be smoked^[131]. They add that “only lean meat is suitable for drying”, because in fat “rancidity quickly develops”^[131]. Their list of suitable meats names beef, camel, sheep, goat and venison, but not pork^[131]. The African products they describe follow this rule. Kilishi in West Africa, odka in Somalia and qwanta in Ethiopia are dried products made of lean beef, goat or lamb^[131].

The European pig is the opposite case. Cato’s Insubrian sows became so fat in spring that they could not stand^[32]. Polybius wrote in the 2nd century BCE that the acorns of the Po plain fed almost all the swine slaughtered in Italy, both for households and for the army^[121]. At Hallstatt the pigs were probably killed in winter^[11]. Fat does not stop water from leaving the lean muscle, but it changes how a piece dries and it turns rancid in warm air^[131]. The larger difference is geometry. Whole legs and sides are thick, and salt and water must travel a long way through them, while thin strips of lean meat dry quickly in warm air. A thick, fat piece cannot be dried in the sun at the beginning of a cold, wet season. For preserving large, fatty pieces without cooking, salt, cool air and smoke offer advantages that rapid drying of thin lean meat in the sun does not, and the Hallstatt reconstruction includes all three^[13].

Cold completes the argument. The Hallstatt meat aged at 6 to 8 °C^[13], and the study of ham salting mentioned above worked at 0 to 6 °C^[29]. The dried meats of Africa are cut into slices or thin strips, as in kilishi and in the Khoikhoi practice that Schapera describes^{[131, 136]}. Whole legs and sides favour a long period of cool processing, because salt penetrates them slowly and the thick muscle loses water much more slowly than thin strips. Before artificial refrigeration, the European winter supplied these conditions naturally.

People Who Could Not Keep the Animal Alive

Salted meat is food for people who cannot keep the animal alive until they need the meat. The Hallstatt miners worked in a valley where animals were hard to keep, and the basins produced more meat than the valley needed^{[10, 11]}. Polybius names the army as a buyer of the pigs of the Po valley^[121], and the Vindolanda accounts show bacon at a frontier fort^[87]. Frost adds the household, because salting allowed a family to eat the meat over the whole year^[27]. The Khoikhoi were the opposite case, because they lived on the milk of their herds and ate the ox at the feast^[133].

China as a Test

A pig keeping culture with cold winters and salt should develop ham without help from Europe, and China did. Zhou and Zhao attribute the earliest record of 金华火腿 (Jīnhuá huǒtuǐ, Jinhua ham) to the Tang dynasty (618 to 907 CE), on the basis of a secondary source, and they state that the name huotui was given by the first emperor of the Southern Song, who reigned from 1127 to 1162. A long tradition does not show that every modern step already existed in the Tang dynasty. Its salting “is only carried out in the winter”, and the best conditions are 5 to 10 °C and 75 to 85 per cent relative humidity^[143]. These figures are close to the 6 to 8 °C of the Hallstatt mine^[13].

Europe and China shared an unusual combination of conditions, and the salt regions of Africa did not have it. The pig gives its value only at death, its carcass is fat and cannot be dried, a cold season allows slow salting, and many people lived apart from the herds. Salt was needed as well, but salt alone produces no ham.

Minced Meat and Sausage. Did China Come First?

The written sources show that China was the first to press meat, as I explain in Pressed Meat: A Chinese Technology Set. For minced meat and sausage the result is different.

Greek sources mention filled casings early. The Odyssey, probably composed in the 8th or 7th century BCE, mentions goat stomachs filled with blood and fat. The poet Hipponax, in the 6th century BCE, compares a gesture to stroking a sausage. In the 5th century BCE Aristophanes made a sausage seller one of the main characters of his play the Knights. This sausage seller carried tripe and casings and sold his goods beside the sellers of salt fish. The Greek allas was a pig intestine filled with meat and fat^[27].

Chinese sources describe a different kind of minced meat. The 周禮 (Zhōulǐ, Rites of Zhou) describes the court of the Zhou dynasty (1046 to 256 BCE) and names 醢 (hǎi, preserved minced meat) among the foods of the court. 鄭玄 (Zhèng Xuán, 127 to 200 CE) explained in his commentary how it was made. The meat was dried and then chopped, mixed with a millet ferment and salt, soaked in good wine and sealed in a jar, and after a hundred days it was ready^[144]. The dictionary 釋名 (Shìmíng, Explaining Names), from about 200 CE, describes finely minced meat that was seasoned with ginger, Sichuan pepper and salt and then roasted^[144].

According to the written sources, the filled casing appears first in Greece. China, on the other hand, recorded a minced, salted and fermented meat that was kept in a sealed jar. These are different techniques. The 齊民要術 (Qímín yàoshù, Essential Techniques for the Welfare of the People, about 544 CE) does describe a filled sheep intestine, but this is more than a thousand years later than the Greek sources^[145]. I see no evidence that China came first with the sausage, as it did with pressing.

Pounding meat on stone is older and more widespread than either technique. Clark Wissler recorded in 1910 that the Blackfoot pounded dried meat “on a stone until fine” and mixed it with heated marrow and other fats to make pemmican^[146]. At Kutoyis in Montana, a bison camp of about 500 years ago, Brandi Bethke and María Nieves Zedeño found stone tools, broken bison bones and a wide pit of the kind used to boil fat out of bones^[147]. Many peoples pounded meat and mixed it with fat. The sausage in a salted casing, like ham and bacon, is a product of pig keepers.

The Carcass as the Unit of Analysis

The history of cured pork is better reconstructed from the fate of the carcass than from the names of finished products. Ham, bacon, Speck and sausage are destinations of different anatomical and compositional parts of the same animal. When a pig is slaughtered, the processor receives the whole edible output at once. Whole muscles can be salted and dried, small pieces of meat and fat can be minced and filled into the animal’s own intestines, fat can be rendered, and bones and connective tissue can be boiled. A mature pork tradition is therefore not simply a method for making ham. It is a system for stabilising and using the carcass.

A Surplus That Arrives All at Once

The slaughter of a pig releases its entire edible output at once. Months of feeding turn into tens of kilograms of perishable tissue in a single event^[27]. Milk, eggs, grain and living animals release food or value step by step, but the pig creates a problem of simultaneity. A cold slaughter season makes this problem easier to manage, and salt then extends the time for eating or exchange. Before slaughter there is one living pig. Immediately afterwards there are many tens of kilograms of meat, fat, blood and organs that spoil quickly, and the whole problem of preservation arrives at the same moment. Cold buys time for processing, salt extends that time, drying reduces the water available to microbes, smoke adds protection, and mincing turns awkward pieces of meat and fat into another stable product. This may be why the European system became a coordinated seasonal activity and not merely a collection of recipes.

Ham and Sausage from One Carcass

The same problem may explain the sausage as well as the ham. A slaughtered pig delivers at the same moment legs, sides, shoulders, head meat, trimmings, fat, blood, intestines and offal. Whole muscles lend themselves to salted cuts. Small pieces of meat and fat need another form of preservation, and the intestine is already there as a casing. Whole muscle curing and sausage making are therefore not separate habits that happened to coexist in Europe. They are complementary solutions to the use of one carcass. Legs become ham, sides become bacon or Speck, shoulder and neck become cured cuts, trimmings and fat become sausage, blood becomes blood sausage, intestines become casings, bones become stock and jelly, and fat becomes lard. Hallstatt already shows several parts of this, namely selected carcasses, a standard division, salting and the use of bones and brine^{[8, 11, 13, 14]}. Whole muscle curing and sausage making solve different parts of the same carcass problem. Their histories need not be identical, and sausage does not arise wherever pigs are killed, but their repeated association in the European pig killing is technologically intelligible. This is why the traditional killing produces a family of products and not one product.

Following the Bones

The appropriate archaeological unit is not the named product but the carcass. Ham, bacon and sausage are later names for different destinations of parts of the same animal. Where the meat has disappeared, the distribution of bones, the age and sex of the animals, butchery marks and processing structures may still reveal the system. The history of cured pork is better reconstructed from the fate of the carcass than from the names of finished products, which were recorded only much later.

Did Pigs Move Between China and Europe?

Pigs were domesticated independently in the Near East and in East Asia^{[148, 149]}. Millet travelled from China to Europe in the Bronze Age, but pigs did not. The genetic studies cited here give no evidence that pigs were exchanged between China and Europe in antiquity, and Chinese pigs are documented in Europe from the 18th century.

European Pigs Came from the Near East and Local Wild Boar

Farmers brought domestic pigs of Near Eastern origin into Europe in the Neolithic, and these pigs reached the Paris Basin by at least the early 4th millennium BCE^[150]. The European pigs then changed. Pigs from 7,100 to 6,000 years ago had both Near Eastern and European ancestry, while later pigs had no more than 4 per cent Near Eastern ancestry. Interbreeding with local wild boar removed almost all the Near Eastern ancestry within about 3,000 years^[85]. Almost all the Hallstatt pigs that were tested belong to the European group of lineages^[8]. The Hallstatt salters therefore cured European pigs. I found no genetic evidence for East Asian pigs in prehistoric or ancient Europe, and none for European pigs in ancient China. A Chinese review of 1994 states that small eared pigs of south China were taken to the Roman Empire during the Han dynasty (206 BCE to 220 CE) and gave rise to the Roman or Neapolitan pig^[151]. The ancient pig genomes studied by Frantz and colleagues do not support this claim^[85].

Chinese Pigs in England

Chinese pigs did reach Europe, but about 3,000 years after Hallstatt. I have written about their role in the English breeds in Kolbroek. Chinese, New Zealand and English Connections and in The English Pig^{[152, 153]}. Writers noted a small black variety in England in the 1720s, and the decisive improved crossbreeds appeared in the last years of the 18th century^[153]. Historical records show that Asian pigs were brought into Europe in the 18th and early 19th centuries^[154]. The genomes of modern pigs date the mixture to about 265 to 270 years ago. Pigs from east China were introduced between 1685 and 1757, and from 1757 to 1841 foreign trade with China was allowed only through Guangzhou in south China^[155]. Breeders used these pigs to improve local pigs, first in England and then in America^[156].

The effect on modern pigs is large. Across European breeds, the average frequency of Asian mitochondrial DNA is 29 per cent, with a range of 0 to 100 per cent within breeds^[157]. About 20 per cent of the genome of commercial European pigs is of Asian origin^[158]. Breeders selected for some of these Asian genes, among them variants of the AHR gene that are associated with larger litters^[159].

Continental Breeds

My own work has dealt mainly with the English breeds, and the genetic studies show that the continental picture differs. The international breeds that came from Britain or were crossed with British pigs carry Asian ancestry. Asian haplotypes occur in Large White, Landrace and in German and Belgian Piétrain at frequencies of 15 to 56 per cent^[160]. In one study the European share of ancestry ranged from 69.6 per cent in Large White to 87.3 per cent in Mangalica^[161]. The old local breeds of the south carry little or no Asian ancestry. Iberian pigs and the Majorcan Black pig have only European mitochondrial haplotypes, because their geographical isolation spared them from the introgression^[160]. Iberian pigs, Cinta Senese and Nera Siciliana of Italy and Mangalica of Hungary show little influence from Asian pigs^[162]. Mangalica carries no East Asian mitochondrial signature^[163], although one region of Asian origin was found in Mangalica, Gloucestershire Old Spots and Large Black^[161]. In Germany, a history written for the breed association states that King Wilhelm I of Württemberg had Chinese pigs brought to his estates near Stuttgart around 1820 and 1821, where they were crossed with local pigs^[164]. This account still needs confirmation from archives.

The old local breeds of southern Europe therefore have little Chinese ancestry^{[160, 162]}. The Chinese pig changed the commercial pig of the 19th and 20th centuries, but the European curing tradition is about 3,000 years older than this influence. No evidence shows pigs travelling from China to Europe with millet, and the curing techniques at both ends of Eurasia developed on local pigs.

Why Central Europe, Italy, Spain and Britain

People made salt on every continent, and across the ancient world they dried, pounded, smoked and embalmed meat. Ham, bacon and sausage became staples, however, in central Europe, Italy, Iberia and Britain, and separately in China.

Europe and China at Opposite Ends of Eurasia

Europe and China developed distinct documented traditions at opposite ends of a much older system of exchange across Eurasia. Textiles and millet show that this system moved techniques and crops in both directions^{[55, 56, 57, 58]}. Whether knowledge of meat curing also crossed it remains unresolved. The pigs were local at each end. Genetic studies have found several centres of pig domestication in Eurasia^[148], among them East Asia^[149], and almost all the Hallstatt pigs that were tested belong to the European group of lineages^[8]. Europe has the older excavated curing industry, at Hallstatt in the Late Bronze Age^[10], while Chinese ham is first recorded at Jinhua in the Tang dynasty^[143]. China was first with pressing meat, and Chinese texts describe the danger of uneven drying, which meat technologists call case hardening^[165]. In pressing and even drying Chinese practice led, and the technique may later have spread west^[165].

The First Records of Ham in Europe and China

Europe has the older record of salted pork. The Hallstatt basins of the 13th and 12th centuries BCE are archaeological evidence of pork curing on a large scale^{[10, 13]}. The oldest European text that names hams is the Captivi of the Roman playwright Plautus, who died in 184 BCE, in which hams hang in a store^[166]. Cato gave the first recipe for salting hams about 160 BCE^{[27, 32]}.

China has early texts on dried meat. The 周易 (Zhōuyì, Book of Changes), whose core text is conventionally dated to the Western Zhou (about 1046 to 771 BCE), speaks of biting 臘肉 (làròu, dried meat)^[167]. Confucius (551 to 479 BCE) accepted 束脩 (shùxiū, a bundle of dried meat strips) as a fee from his pupils^[168]. The 周禮 (Zhōulǐ, Rites of Zhou), compiled in the Warring States period (475 to 221 BCE), names an officer, the 腊人 (xīrén, keeper of dried meat), who was in charge of the dried meat of hunted animals^[169]. The first Chinese recipe that names domestic pork is in the 齊民要術 (Qímín yàoshù, Essential Techniques for the Welfare of the People, about 544 CE). Its five flavour dried meat could be made from beef, mutton, deer, wild pig or domestic pig, and salt was added only to taste, with the instruction 勿使過鹹 (wù shǐ guò xián, do not make it too salty)^[145]. Tradition places the name 火腿 (huǒtuǐ, ham, literally fire leg) in the Song dynasty, and Zhou and Zhao, the historians of Jinhua ham, write that the history of its processing technology “is impossible to trace exactly”^[143].

The evidence for an independent Chinese development is strong for the pig and for dried meat, and weaker for ham. Pigs were domesticated independently in China^{[149, 170]}. The Chinese words for dried and minced meat belong to a native vocabulary that appears in the earliest texts. The Qimin yaoshu dries meat with light salt, while Cato packs hams in heavy salt, although this contrast is my own reading of the two texts. For ham itself, however, the Chinese record begins more than a thousand years after Cato and about two thousand years after Hallstatt. The dates therefore do not exclude a western origin of the Chinese salted pork leg.

My hypothesis is that Hallstatt methods could have moved east through the Tarim region and Turpan, while Europe described them in writing only much later. No find or text supports this transfer at present, and it remains speculative. Other foods and techniques did move east along this route. Wheat reached Gansu and Xinjiang around 1900 BCE^[68], and kefir cheese from the Tarim Basin spread into inland East Asia^[75]. The hypothesis could be tested by a Chinese text or find of salted pork legs older than the Han dynasty, or by a Chinese curing method that repeats arbitrary features of the Hallstatt or Cato procedures, such as opening the carcass from the back.

Why the Products Are So Similar

The similarity lies in the operations rather than in the product names, most of which are recent^{[119, 120]}. Across Europe the same processing sequence appears. A whole pig is divided into cuts that can be recognised by their anatomy. The leg and the side are preserved with salt, time and the cold season, then hung and dried, and smoked where the climate requires it. The remaining meat and fat are minced, salted and filled into the intestines, and almost the whole carcass is used^{[13, 27, 32, 88, 89]}. The continuity is a continuity of unit operations, which is how a meat scientist describes a process, and the regional specialities of Europe are variations on this common base. These operations form what may be called a processing grammar. The regions changed the vocabulary of products and recipes, while they kept much of the underlying grammar of animal selection, seasonal slaughter, anatomical division, salting, drying, smoking, maturation and use of the remaining carcass.

Protein chemistry explains why the base works so well. Salt lowers the water activity of whole muscles and keeps them safe in the cold^[171], and in minced meat salt dissolves the myofibrillar protein myosin, which binds the sausage when it is heated^[172]. Three kinds of similarity must therefore be distinguished. Anatomical similarity follows from the pig, which has the same structure everywhere. Technological similarity follows from salt, drying, temperature and smoke, which work by the same physical and chemical rules everywhere. Cultural similarity follows from people who learn particular ways of cutting, salting, handling and preparing meat from other people. The first two can explain independent development in different places. The third is where historical transmission becomes important, and the Hallstatt bones and the Gailtal method are evidence of this third kind^{[8, 11, 12]}. It is no accident that this base stayed so stable.

The common method and the recipe must also be distinguished. The common method consists of pig selection, seasonal slaughter, division of the carcass, salt, time, temperature, removal of water, smoke where it is needed and the use of the remaining meat and fat. A recipe specifies the exact cut, the amount of salt, the number of days, the smoke, the spices, the shape and the maturation. Independent invention can easily reproduce parts of the common method, because anatomy and physics limit the possibilities. Repeated agreement in several arbitrary choices points more strongly to transmission. The names change from ham to Speck, bacon and prosciutto, and recipes, spices, smoke and salt levels change too. The sequence stays the same. The animal is selected, killed in season and divided by anatomy, the cuts are assigned by function, salted and dried, smoked where it helps and matured, and the trimmings, fat and secondary products are used. This is why regional traditions can differ widely and still belong to one technological family.

A Test for Technological Relationship

The evidential value of a similarity grows with the number of reasonable alternatives. If physics almost forces everyone to do something, it says little about cultural transmission. If there are many reasonable ways of doing something and two populations choose the same unusual one, it says much more.

Similarities can therefore be weighed. What counts is not whether two peoples both salted pork, but how improbable a particular similarity would be if they had invented it independently.

SIMILARITY BETWEEN TWO TRADITIONS	WEIGHT AS EVIDENCE OF TRANSMISSION
Both salt pork	Weak, because salt works the same way everywhere
Both cure the leg	Weak, because anatomy explains it
Both slaughter in winter	Moderate, because climate explains much of it
Both use the same unusual division of the carcass	Strong
The same unusual division and a similar process	Stronger
The same unusual process with a connection in place and time	Very strong

Weighing evidence for technological transmission.

In detail, that two peoples salt pork is weak evidence of a connection. That both preserve the leg is also weak, because anatomy explains it. That both slaughter in winter is moderate evidence, because climate explains much of it. That both open the carcass from the back and remove the spine and ribs is much stronger. Comparable specialised structures and the same retained portions are stronger still, and the same unusual sequence combined with a connection in place and time is the strongest evidence of all.

This answers an obvious objection, namely that ham traditions look alike simply because everyone had pigs and salt. The anatomy of the pig explains why people preserve legs, and the chemistry of salt explains why salting works. Neither explains why a society selects castrated males of a narrow age, divides thousands of carcasses in the same way, concentrates processing at a salt centre, follows repeated procedures of salting and maturation, and later reproduces comparable procedures across large regions^{[8, 11, 12, 94]}.

Within the common base, regions differ. Some traditions rely mainly on drying in air, and others make more use of smoke. Some preserve whole legs, and others concentrate on sides and smaller cuts. These differences show how a common technology adapted to local climate, raw material and markets. Climate decides the finishing step. Drier regions can rely more on drying in air, while cooler or wetter regions gain more from smoke. Colder regions have longer natural curing seasons, and warmer regions need different timing, salt loads, sizes of piece or altitude. I suggest that Parma ham, Iberian ham, Alpine Speck and British bacon need not be unrelated inventions. They can be regional variants of one common method. The history of whole muscle products also need not follow the same route as the history of sausages and fermented products, although they share salt, cold and the chemistry of muscle protein.

Central Europe, Italy, Iberia and Britain had the conditions described above in common, and they also had forests for pigs, large supplies of salt and large herds^{[32, 33, 93, 103, 115, 121]}. Several influences then made their practices more alike. Neolithic farmers spread salt making, and most languages of Europe share one word for salt^{[6, 97, 104]}. In the Late Bronze Age one culture spread across the continent, and people moved from France to Britain^{[80, 86]}. These lands later became the western provinces of Rome, which created markets, price grades and army rations from the Pyrenees to the frontier in northern Britain^{[87, 88]}. The Carolingian estates received a single written list of products^[89]. Medieval calendars all over Europe showed the same farming year, with acorns in November and the killing of pigs in December^[122], and butchers’ guilds set standards for how meat was cut^[90]. Each of these influences made the practices more similar. Rome was the strongest documented institutional bridge between the continent and Britain, because Britain was later outside the realm of Charlemagne^{[87, 88, 125]}. Continental contact, however, had reached Britain long before Rome^[80].

Africa

Africa had plenty of salt and even used it as money^[130], but it lacked the other conditions. Pigs were rare or absent in most of its salt regions, the herds gave lean meat that dried well in warm air, and herders such as the Khoikhoi lived on milk and did not need stores of meat^{[131, 133, 141]}.

Preserved Meat in Ancient Records

Ancient writers and later ethnographers described how many peoples preserved meat. Their reports show two main methods. Some peoples dried lean meat in warm, dry air, and others salted fat pork in the cold. The table lists the records cited in this article by date.

REGION OR PEOPLE	DATE OF RECORD	METHOD RECORDED
Alps, Hallstatt	13th to 12th century BCE	Pork salted in log basins and aged in the mine[8, 10, 13, 14]
Egypt	18th Dynasty, 1386 to 1349 BCE	Meat and poultry for the tomb dried, bandaged and treated with resin balms[173]
Greece	8th to 5th century BCE	Stomachs and pig intestines filled with blood, fat and meat[27]
Egypt	5th century BCE	Fish dried in the sun or cured in brine, small birds cured and eaten raw[174]
Po plain, Italy	2nd century BCE	Swine fattened on acorns for households and the army[121]
Gaul	1st century BCE to early 1st century CE	Pork eaten fresh and salted, flitches and hams sent to Rome[32, 33]
Pyrenees, Carretanians	Early 1st century CE	Hams that rival those of Cantabria[112]
China, Zhou court	Commentary of the 2nd century CE	Dried meat chopped, salted, fermented with wine and sealed in a jar for 100 days[144]
China, Jinhua	Tang dynasty, 618 to 907 CE, onward	Ham salted only in winter, at 5 to 10 °C[143]
Sahara, Taghaza	1352	Salt mined in slabs and used as money[130]
Khoikhoi, Cape	1775	Meat eaten fresh or dried in the sun, salt refused[135]
Tswana	1803 to 1806	Natron or plant ash used in place of salt[134]
Blackfoot, Plains	1910	Dried meat pounded on a stone and mixed with fat[146]
Khoikhoi, Cape	1930	Thin strips salted and dried in the air[136]
West, East and southern Africa	1990, traditional products	Lean beef, goat or lamb dried as kilishi, odka, qwanta and biltong[131]

Preserved meat in ancient texts, archaeology and ethnography, from the oldest record to the most recent.

Drying is used where the air is warm and dry and the animals are lean. The products are thin, and salt is either not used or used only on thin strips. Salting is used where pigs, oak forest and a cold season occur together. The products are whole legs, sides and filled casings. Egypt falls between the two. Egyptians cured fish and birds in brine and embalmed their dead with natron, but according to Herodotus they considered the pig unclean^{[142, 174]}.

Egypt. Embalming and Preserved Meat

Egypt has the best ancient evidence that people used the same substances on meat and on human bodies. On EarthwormExpress I have argued that people preserved meat first and that embalmers later used the same methods^{[175, 176]}.

Herodotus visited Egypt in the 5th century BCE. He wrote that the Egyptians dried some of their fish in the sun and ate others “cured in brine”. They also ate quails, ducks and small birds without cooking, “after first curing them”^[174]. Salima Ikram lists drying, dry and wet salting, smoking, combinations of these methods, and curing with fat, beer or honey as Egyptian ways of preserving meat^[177]. Meat for the tombs was treated like human bodies. Clark, Ikram and Evershed analysed offerings of meat and poultry that “were mummified to ensure their preservation”. A beef rib from the tomb of Yuya and Tjuia, from the 18th Dynasty (1386 to 1349 BCE), was coated with a balm rich in Pistacia resin, which the authors consider more sophisticated than the balms on many human mummies of the same period^[173].

Embalmers used natron to dry the body. Herodotus wrote that in the most expensive method the body was kept in natron for seventy days^[174]. Embalming recipes are older than the pharaohs, because linen wrappings from graves at Mostagedda in the Badari region, from the 5th and 4th millennia BCE, contain resins, plant extracts and oils^[178]. Nerlich, Falter and Zink placed one pig heart in natron and another in sea salt at 37 °C for up to 69 days. The heart in natron lost water faster and its tissue was better preserved, and the authors conclude that the Egyptians learned by experience that natron worked better than sea salt^[179]. Salt also preserved bodies without any embalmer. In 1734 miners at Hallstatt found the body of a man “mummified by salt”, who was buried in the churchyard^[65], and at the Dürrnberg near Hallein records from 1573 and 1616 describe well preserved bodies of Iron Age miners^[180]. On the Atacama coast, the Chinchorro, who lived there from about 5450 to 890 BCE, made the oldest known artificial mummies^[181].

Valerie Wohl, whom I cite in the same chapter, wrote that “methods common at the time for preserving meat, fowl or fish probably suggested a clue for early techniques” of embalming^[175]. Honey shows the same overlap. Alexander the Great died in Babylon in 323 BCE, and he is reported to have been placed in a coffin filled with white honey^[176], while Ikram lists honey among the substances that Egyptians used to cure meat^[177]. Meat and bodies were preserved with the same methods, but not which came first. The oldest dated embalming recipes are from the 5th and 4th millennia BCE^[178], and I have found no equally old dated evidence for salted meat in Egypt. Embalming records are therefore among the few sources that date the use of particular salts on flesh. Binkerd and Kolari proposed in 1975 that curing meat with salts containing nitrate began in the salt deserts of western Asia^[175].

Egypt and the Celts

Celts did serve a dynasty of pharaohs. The Ptolemies, the Macedonian kings who ruled Egypt from 305 to 30 BCE, hired Celtic mercenaries. Pausanias, who wrote in the 2nd century CE, records that Ptolemy II engaged “some four thousand Gauls”. When they plotted to seize Egypt, he left them on a deserted island in the Nile, where they died^[182]. Painted grave slabs from a soldiers’ tomb in Alexandria, from the second half of the 3rd century BCE, name at least three Galatian soldiers, who were Celts from Asia Minor^[183]. Other links are legend. The Irish story of Scota, daughter of a pharaoh, belongs to the Lebor Gabála Érenn (Book of the Taking of Ireland), a medieval history built on a biblical framework^[184]. A study of the royal family of Tutankhamun reported the Y chromosome haplogroup R1b, but its authors place the origin of this lineage in the Near East and not among the Celts^[185].

Hallstatt could not have taught the Egyptians to embalm, because Egyptian embalming recipes date from the 5th and 4th millennia BCE^[178], and the balmed beef rib of Yuya and Tjuia is older than the Hallstatt basins^[173]. Contact between Egypt and Europe in the centuries of the basins is, however, proven. Glass beads of Egyptian origin from the 14th century BCE reached Denmark, and Varberg, Gratuze and Kaul describe contact between Egypt, Mesopotamia and Denmark in the 14th to 12th centuries BCE^[186]. Knowledge of preserving flesh could therefore have travelled from Egypt towards Europe along the same chains of exchange. No source yet shows that it did.

What People Knew Before Chemistry Explained It

Chemistry and biochemistry explain results that people achieved for thousands of years without knowing why. People learned these results through long experience of salting, pounding, cooking and drying meat.

Salt Preserves Meat Without Heat

Meat kept when it was buried in salt. At Hallstatt pork stayed in salt for seven to ten days^[13], Cato kept his hams in salt for twelve days^{[27, 32]}, and Egyptian embalmers kept bodies in natron for seventy days^[174]. Salt on the surface stops microbes from growing, and the salt crystals absorb some of the water that comes out of the meat^[131]. Science explained this with the concept of water activity, the ratio between the vapour pressure of a food and that of pure water^[171]. W.J. Scott developed this concept for food spoilage in the 1950s^[187]. According to the FDA, Clostridium botulinum needs a water activity of at least about 0.93 to grow^[171]. Preservation depends on the salt dissolved in the water of the meat. In dry cured ham the water activity depends mainly on the salt content expressed per kilogram of water^[188], so a piece with more water needs more salt to reach the same effect. Salt therefore protects meat while most of its water is still in it.

Salted Minced Meat Binds

Minced meat that is mixed with salt and worked holds together. The Greek sausage, the minced and salted meat of the Shiming (釋名, Shìmíng, Explaining Names, about 200 CE) and Lahner’s Frankfurter all depend on this^{[27, 119, 144]}. Salt at 2 to 3 per cent breaks up the myosin filaments of the muscle, so that myosin dissolves. When the meat is heated, the dissolved myosin forms a gel that holds the product together, and the more myosin is extracted, the better the product binds^[172]. Every sausage maker who felt salted mince become sticky saw the extraction of myosin. This conclusion is mine, but it follows from the mechanism.

Old Brine Cures Faster

The Hallstatt reconstruction already describes brine that came out of the meat and was used again until it spoiled^[13]. In my review of the history of bacon curing I showed that reused brines became the basis of the industrial bacon plants of Denmark and of tank curing, also called the Wiltshire cure^[24]. The old brine contained nitrate that bacteria had changed into nitrite^[24]. Polenske found nitrite in curing brines in 1891^[26], and Haldane explained the red colour of cured meat in 1901^[91]. Nitrate reductase, an enzyme of staphylococci, changes nitrate into nitrite in meat^[25]. For centuries a red colour and a fast cure from old brine were the visible signs of this bacterial chemistry.

Fermented Meat Keeps

In the 2nd century CE, Zheng Xuan described dried minced meat that was mixed with a millet ferment and salt, soaked in wine and sealed for a hundred days^[144]. Much later, curers found that sugar made the cure faster and the colour better^[24]. Lactic acid bacteria change sugars into lactic acid and lower the pH of the meat^[25]. The sealed jar and the added sugar fed the bacteria that made the meat safe, although the cooks knew only the result.

Fat Spoils and Fat Protects

The FAO manual states that only lean meat is suitable for drying, because fat quickly becomes rancid^[131]. Yet fat also protected meat. Frost notes that the fat in sausages helped to protect the meat from bacteria^[27], Ikram lists curing with fat among the Egyptian methods^[177], and the Blackfoot mixed pounded dried meat with fat to make pemmican^[146]. Fat spoiled when it lay in thin layers in warm air, but it preserved meat when it surrounded it. I think the difference is the supply of oxygen, because rancidity is a form of oxidation. The sources cited here describe only the practice.

Boiled Bones Give Jelly

At Hallstatt, bones were boiled until the liquid set to a jelly that could be dried^[14]. The Qimin Yaoshu (齊民要術, Qímín yàoshù, Essential Techniques for the Welfare of the People, c. 533 to 544 CE) describes how hides were boiled into glue, which was then set and dried in thin cakes^[165]. Collagen is a triple helix that begins to unwind at about 57 to 62 °C and turns into gelatin at 70 to 80 °C. The gelatin dissolves in the hot liquid and sets again when it cools^{[189, 190]}. The people of Hallstatt made dried jelly about 3,000 years before anyone knew the structure of collagen.

Pressing and Pounding Remove Water

Columella instructed that boned pork be pressed between weighted boards for three days before it was salted again^[27]. In China, meat and fish were pressed while they dried^[165], and the Blackfoot pounded dried meat on a stone until it was fine^[146]. Our study of pressed meat explains pressing as a way to stop the surface from drying faster than the inside, a fault called case hardening^[165]. Pressing pushes water out of the inside of the meat and spreads it evenly between thick and thin parts. Pounding is done on meat that is already dry. I think it breaks the dry fibres into a powder that absorbs fat, and this powder is the basis of pemmican.

Protein Technology in China

Chinese sources show a long practical command of protein, salt and water. The 齊民要術 (Qímín yàoshù, Essential Techniques for the Welfare of the People), written by 賈思勰 (Jiǎ Sīxié) about 544 CE, gives the season as well as the method. Five flavour dried meat (五味脯, wǔwèi fǔ) was best made in the 1st, 2nd, 9th and 10th months, which are the cool months of the Chinese year^[145]. Fermented fish packed in cooked rice (魚鮓, yú zhǎ) was made in spring and autumn, and not in winter or summer^[145]. Glue (膠, jiāo) was boiled from hides only in the 2nd, 3rd, 9th and 10th months, because in other months it would not set, and fatty or salted hides were unsuitable^[145]. The same book describes a filled intestine (灌腸, guàncháng). Sheep intestine was filled with minced mutton seasoned with salt, the juice of fermented beans, ginger and pepper, and then roasted^[145]. Other Chinese texts describe squeezing meat by hand until it was firm and compact, salting and pressing it three times, and avoiding uneven drying^[165].

Each of these rules works through proteins. Salt dissolves myosin and makes minced meat bind^[172]. Collagen in hides turns into gelatin when it is boiled and sets when it cools^{[189, 190]}. Pressing moves water evenly through the muscle, so that the surface does not harden before the inside dries^[165]. Chinese cooks also set proteins with salts outside meat. Tofu is soy milk coagulated with nigari, a salt that consists mainly of magnesium chloride, or with gypsum. Its earliest known mention is in the 清異錄 (Qīng yì lù, Records of the Pure and the Strange) of 陶穀 (Táo Gǔ), written about 950 CE, and the legend that tofu was invented in the 2nd century BCE has no support in the texts of that time^[191]. None of these writers knew the mechanism. They knew the results and recorded them as rules of season, salt and pressure.

Practice Before Theory

People followed each of these rules for centuries or millennia before science explained it. Water activity was defined in the 1950s^[187], the role of nitrite in curing was explained between 1891 and 1901^{[26, 91]}, and the role of myosin in binding in the 20th century^[172]. Meat curing was a practical science of protein, salt and water long before chemistry could explain it.

Turpan and the Nitrate Question

My work on this subject began with a question about Turpan. The Turpan-Hami region of northwestern China holds a very large nitrate deposit that formed from the atmosphere. Its resources are comparable to those of the Atacama Desert, and the nitrate is concentrated near the surface and not at depth^[192]. In 2017 I argued that crushed soil from this region, rubbed on meat, would preserve it, and that curing with nitrate began in this region^[193]. I later wrote that nitrate curing developed into an art there^[194]. Saltpetre is potassium nitrate and sal ammoniac is ammonium chloride. They are different substances, and the history of each needs its own sources. I have also noted that Turpan itself has no known great tradition of meat curing^[195].

The trade in sal ammoniac from this region is documented. At Astana, the cemetery of Turpan, people made shoes, belts, hats and clothing for the dead from old paper, and they “recycled government documents, contracts, and other texts to make these funeral vestments”. Nearly two thousand documents have been recovered from 205 tombs^[196]. Among them are 37 receipts for a fee on trade, probably from about 600 CE. Of the 49 traders named in them, 41 have Sogdian names, and ammonium chloride appears six times among the goods. Valerie Hansen notes that ammonium chloride was used as a medicine and as a flux in the melting of metals and in dyes^[196]. The 隋書 (Suí shū, Book of Sui, compiled in 636 CE) lists 鐃沙 (náoshā, sal ammoniac) among the products of Kucha in the Tarim Basin and of 康國 (Kāngguó, the Kang kingdom, Samarkand)^[197]. Sal ammoniac therefore moved between the Tarim Basin, Turpan and Samarkand by about 600 CE, and Chinese authors agree that it came into China from the west^[194].

Knowledge of saltpetre on this part of the Silk Road went beyond trade. A medical manuscript from Dunhuang, the oasis east of Turpan, is attributed to 陶弘景 (Táo Hóngjǐng, 456 to 536 CE), and it probably dates from the early Tang dynasty, perhaps the 7th century. For acute pain of the heart it tells the healer to lift the patient’s tongue and sprinkle saltpetre under it. Butler and Moffett, who studied the text, describe it as a medieval Chinese treatment for angina^[198]. People in this region therefore knew in the first millennium CE that saltpetre acts on the body, long before chemistry explained the effect of nitrate.

Turpan itself has no known tradition of curing pork, and one possible reason is that it had few or no pigs. Ancient DNA from leather objects in the Bronze Age cemeteries of Yanghai near Turpan and Wupu near Hami identified goat, sheep and cattle^[199]. In the eastern Tianshan in the first millennium BCE, sheep and goats made up 86.3 per cent of the identified animal bones, followed by cattle, dogs and horses^[200]. I have found no published pig bones from the Turpan basin. The region remained Buddhist until the Ming dynasty (1368 to 1644), when Islam became dominant^[201]. My hypothesis that a curing tradition died out with the pigs is therefore possible, but the published bones give little sign that pigs were ever common there.

Could salts from Turpan have reached Hallstatt? The documents are about 1,800 years younger than the basins, and no text or find yet shows nitrate or sal ammoniac moving west in the 2nd millennium BCE. The rock salt of Hallstatt, the Haselgebirge, consists of halite, anhydrite, polyhalite and mudrock, and no nitrate minerals are reported in it^[202]. No published study has analysed the basins for nitrate, nitrite or ammonium. This remains open, and it can be tested. Mineral analysis of the clay fill and the timbers of the basins for these ions would show whether salts other than the local rock salt were used.

Nitrate curing is a second technological history. The Hallstatt evidence concerns preservation by salt, the removal of water, cold and possibly smoke. The Turpan question concerns the curing salts and the red colour of cured meat. European pork preservation and nitrate curing therefore need not have the same geographical origin, although they may have met. Long distance interaction across Bronze Age Eurasia is shown by the movement of crops, technologies and populations^{[55, 56, 57, 58, 73]}. These movements show that practical knowledge could pass through chains of connected communities, and they place Hallstatt and the Tarim region within one world of exchange. They do not yet establish a direct route between Hallstatt and Turpan.

The region is also linked with removing water from food. The kefir cheese of Xiaohe in the Tarim Basin, from about 1900 to 1700 BCE, is an exceptionally early preserved example of a complex dairy tradition in the region, more than a thousand years older than the first Chinese texts on dried meat. The sources do not show whether the Xiaohe curd was pressed^{[74, 165]}. The texts on pressing meat come from China proper and not from Turpan^{[145, 165]}. The two technologies therefore belong to the same wider region of Xinjiang and northern China, but not to the same place.

Weaving techniques, crops, dairy cultures and bone skates moved through this corridor, and knowledge of curing salts could have moved in the same way. The hypothesis that nitrate curing became an art in or near Turpan cannot be dismissed, but it is not yet proven. It needs chemical analysis of meat residues or salts from early sites in Xinjiang, or a dated text that describes the use of saltpetre or sal ammoniac on meat.

How Curing Salts Could Have Reached Hallstatt

My hypothesis is that salts containing nitrate or ammonium were known at Hallstatt. Two routes are possible. The first is trade. Hallstatt was wealthy, and it lay within the networks that carried millet from East Asia to the Alps and twill weaving across Eurasia^{[55, 56, 57, 58, 73]}. A salt as valuable as sal ammoniac, which Sogdian merchants later traded at Turpan^[196], could have travelled along the same chains of communities. Nothing in the evidence rules this out. The gap is that no find or text yet places these salts in the west before about 600 CE.

The second route is local. Urea in urine breaks down to ammonia, and bacteria in the soil turn ammonium into nitrate wherever urine and dung soak into earth, in stables, latrines and manure heaps. The saltpetre makers of early modern Europe produced nitrate in this way, from the earth of stables, dovecotes and privies^[203]. Every community that kept livestock therefore had a source of ammonia and nitrate close at hand. In my trials in Cape Town, meat that I treated to reproduce the Hallstatt process repeatedly putrefied before it produced ammonia in significant quantities^[204]. For this reason I think that an outside source of ammonia, such as urine, may have been added. Curing could have begun with urine and with salts that formed from it, and the same effect could later have been recognised in sal ammoniac and saltpetre. I have also argued that the two salts were easily confused, so that nitrate could have been traded as sal ammoniac^{[193, 194]}.

Both routes can be tested at Hallstatt. Mineral analysis of the clay fill and the timbers of the basins for nitrate, nitrite and ammonium would show whether such salts were present, if traces have survived three thousand years in the damp salt. Where nitrate is found, its oxygen isotopes could separate the two routes, because the nitrate of Turpan carries the isotopic signature of nitrate formed in the atmosphere^[192], while nitrate formed by bacteria from urine and dung does not. One analysis could therefore show whether curing salts were used at Hallstatt and also where they came from.

Conclusion

Hallstatt does not tell us when Europeans first discovered that salt preserves pork. It shows something historically more consequential. By the 13th and 12th centuries BCE, pork preservation in the Eastern Alps had become an organised production system. Animals were supplied according to an unusually narrow biological profile, carcasses were prepared by a repeated anatomical procedure, preservation took place in specialised installations, the natural environment of the mine supplied conditions for maturation, secondary materials were recovered, and production exceeded immediate local needs^{[8, 10, 11, 12, 13, 14]}. Hallstatt is therefore the earliest pork curing industry demonstrated in Europe at present. Six changes can be seen there together. Husbandry became procurement, butchery became standardised production, salt mining became food processing, the carcass became a set of products, preservation turned perishable meat into goods that could travel, and repeated practical knowledge became a technological tradition.

Hallstatt is therefore important not because it proves where Europeans first salted pork, but because it is the earliest place known at present where the elements of the later European pork curing system can be seen operating together on an industrial scale. The evidence does not yet prove that the later traditions of Gaul, Italy, Britain and central Europe descend from Hallstatt. It does show that such a system existed in the Eastern Alps by the Late Bronze Age, that Europe had the networks through which it could spread, and that later European curing traditions repeatedly combined the same underlying operations. Among the strongest signs that Hallstatt was an industry and not a large communal act of preservation is the specification of its animals. A processor can select suitable carcasses after slaughter, but a supply system that repeatedly delivers animals of the required sex, age and condition is something more^[11].

Whether this system originated at Hallstatt cannot yet be shown. What can be shown is that by the 13th and 12th centuries BCE it was already mature there. The later European record does not require every region to have rediscovered the complete sequence independently. Late Bronze Age Europe had the networks through which practical knowledge could circulate^{[55, 57, 58, 80]}. Iron Age Acy-Romance shows the deliberate selection of pork portions for salting^[94]. Cato records a defined salting procedure^{[27, 32]}. Varro and Strabo describe regional industries that supplied salted pork far beyond their own communities^{[32, 33]}. There is no evidence that the Hallstatt pork industry depended on pigs from China, or that Chinese ham depended on European pigs^{[8, 85]}. The question that follows is therefore whether the system first visible at Hallstatt belongs among the ancestral traditions from which the closely similar pork curing traditions of western and central Europe developed. The table sets out what each kind of evidence shows.

OBSERVATION	INTERPRETATION	KIND OF EVIDENCE
Salt at Hallstatt, the Seille valley, Droitwich and in the Sahara[10, 93, 98, 130]	Preservation was possible	Direct evidence
102 male and 9 female jaws at Hallstatt[11]	Animals supplied to a specification	Direct archaeological pattern
Slaughter age of one and a half to two years[11]	Controlled supply	Direct pattern, with the cause interpreted
Same cutting technique on thousands of bones[8, 14]	A learned procedure	Direct pattern
Missing trunk bones[11]	Carcass prepared elsewhere	Zooarchaeological inference
Log structures with salty clay fill and bones[10, 13]	Specialised curing installation	Archaeological interpretation
Narrow gap beside one basin[13]	Collection of liquid released during salting	Reconstruction
Seven to ten days in salt, one third weight loss in six months[13]	Salting and drying regime	Experimental reconstruction
Size of the basins and quantity of bones[10, 23]	Production beyond local need	Archaeological interpretation
Trotters and backbones discarded before heads and limbs at Acy-Romance[94]	Portions kept for curing	Archaeological interpretation
Back opening of the carcass in the Gailtal and at Kaning today[12]	Possible cultural retention	Modern analogy
Roman texts and the price edict[32, 33, 88]	A commodity system	Textual evidence

Kinds of evidence for organised pork curing, how each is interpreted and what kind of evidence it is.

Two research questions now have the highest priority. The first is whether the meat industry outlived the Bronze Age mine after the debris flow of 1245 BCE, because that would show that meat processing had become an activity in its own right^{[15, 17]}. The second is whether Hallstatt and the settlements that supplied it produce anatomically complementary bone assemblages, tested together with age and sex profiles, radiocarbon dates, strontium isotopes and ancient DNA. The decisive work lies in the animal bones of Europe between Hallstatt and Acy-Romance.

About a thousand years later the Gauls and their Iberian and Italian neighbours were known as the best producers. Rome turned their products into goods traded between regions, used its salting installations for meat as well as fish and carried salted pork to its frontier in Britain^[95], and it is the strongest documented institutional bridge between the continent and Britain^{[32, 33, 87, 88, 112]}. The Carolingian estates, the farming calendar and the guilds then reinforced and reproduced a tradition that was already widespread, and in the cities of the 19th century it became an art^{[89, 90, 119]}. The Hallstatt bones and the Gailtaler Speck of today show the same division of the carcass from the back, in the same mountains, about 3,000 years apart^{[11, 12]}. The common technology is old, and the regional differences are younger. China preserves a separate documented curing tradition at the other end of Eurasia^[143]. Across much of the ancient world two contrasting ways of preserving meat can be recognised, alongside cooking, fermentation and their combinations. Lean meat could be dried rapidly in warm, dry air. Fat pork, by contrast, could be salted and stabilised through the cold season. For most of its history people learned the second way from one another by doing it.

References

1. Leshem, M. (2009). Biobehavior of the human love of salt. Neuroscience and Biobehavioral Reviews 33(1), 1 to 17. cris.haifa.ac.il
2. Hurley, S.W. and Johnson, A.K. (2015). The biopsychology of salt hunger and sodium deficiency. Pflügers Archiv 467(3), 445 to 456. doi.org/10.1007/s00424-014-1676-y
3. Te Ara, the Encyclopedia of New Zealand. Salt. Page 1, Sea salt. teara.govt.nz/en/salt/page-1
4. Antonites, A. (2013). Archaeological salt production at the Baleni Spring, Northeastern South Africa. South African Archaeological Bulletin 68(168), 105 to 118. hdl.handle.net/2263/40530
5. Antonites, A. (2005). The Salt of Baleni. An archaeological investigation into the organization of production during the Early Iron Age of South Africa. MA dissertation, University of Pretoria. hdl.handle.net/2263/30986
6. Weller, O. and Dumitroaia, G. (2005). The earliest salt production in the world: an early Neolithic exploitation in Poiana Slatinei-Lunca, Romania. Antiquity 79(306), Project Gallery. antiquity.ac.uk/projgall/weller306
7. Flad, R., Zhu, J., Wang, C., Chen, P., von Falkenhausen, L., Sun, Z. and Li, S. (2005). Archaeological and chemical evidence for early salt production in China. Proceedings of the National Academy of Sciences 102(35), 12618 to 12622. doi.org/10.1073/pnas.0502985102
8. Hammer, S.E., Tautscher, B., Pucher, E., Kowarik, K., Reschreiter, H., Kern, A. and Haring, E. (2018). Bronze Age meat industry: ancient mitochondrial DNA analyses of pig bones from the prehistoric salt mines of Hallstatt (Austria). BMC Research Notes 11, 243. doi.org/10.1186/s13104-018-3340-7
9. Agence France-Presse (August 2018). Salt of the Alps: ancient Austrian mine holds Bronze Age secrets. Interview with Hans Reschreiter, Natural History Museum Vienna. phys.org
10. Naturhistorisches Museum Wien. Bronze Age meat curing vats. nhm.at/hallstatt
11. Naturhistorisches Museum Wien. Results of animal bone analyses from the Salzbergtal valley. Text by E. Pucher. nhm.at/hallstatt
12. Naturhistorisches Museum Wien. Bronze Age meat processing around the mine in Hallstatt. nhm.at/hallstatt
13. Barth, F.E. and Lobisser, W. (2002). Das EU-Projekt Archaeolive und das archäologische Erbe von Hallstatt (The EU Project Archaeolive and the Archaeological Heritage of Hallstatt). Vienna: Naturhistorisches Museum. Cited from the English translation by Christa van Tonder-Berger in reference 15.
14. Pucher, E., Barth, F.E., Seemann, R. and Brandstätter, F. (2013). Bronzezeitliche Fleischverarbeitung im Salzbergtal bei Hallstatt (Bronze Age Meat Processing in the Salzbergtal near Hallstatt). Mitteilungen der Prähistorischen Kommission 80. Vienna: Verlag der Österreichischen Akademie der Wissenschaften. library.oapen.org
15. Naturhistorisches Museum Wien. Bronze Age (salt mine). Text by H. Reschreiter, K. Kowarik and C. Loew. nhm.at
16. Naturhistorisches Museum Wien. Wood research. Text by M. Grabner. nhm.at
17. Grabner, M., Wächter, E., Nicolussi, K., Bolka, M., Sormaz, T., Steier, P., Wild, E.M., Barth, F.E., Kern, A., Rudorfer, J., Kowarik, K., Stöllner, T. and Reschreiter, H. (2021). Prehistoric salt mining in Hallstatt, Austria. New chronologies out of small wooden fragments. Dendrochronologia 66, 125814. doi.org/10.1016/j.dendro.2021.125814
18. Naturhistorisches Museum Wien. Mining in the Hallstatt Period. Text by H. Reschreiter and K. Kowarik. nhm.at/hallstatt
19. Naturhistorisches Museum Wien. Bronze Age mining. Text by H. Reschreiter and K. Kowarik. nhm.at/hallstatt
20. Xue, J.L., Dial, G.D. and Pettigrew, J.E. (1997). Performance, carcass, and meat quality advantages of boars over barrows. A literature review. Swine Health and Production 5(1), 21 to 28. aasv.org
21. Naturhistorisches Museum Wien. Bronze Age (site). Text by H. Reschreiter, K. Kowarik and C. Loew. nhm.at
22. van Tonder, E. (2024). The Hallstatt Curing Method. EarthwormExpress. earthwormexpress.com
23. Reschreiter, H. and Kowarik, K. (2019). Bronze Age Mining in Hallstatt. A New Picture of Everyday Life in the Salt Mines and Beyond. German summary: Der bronzezeitliche Bergbau in Hallstatt. Neue Lebensbilder zum Salzbergwerk. Archaeologia Austriaca 103, 99 to 136. doi.org/10.1553/archaeologia103s99
24. van Tonder, E. (2016). Bacon Curing. A historical review. EarthwormExpress. With citations of Lauer (1991) on saltpetre and colour, of Hoagland on nitrite and nitric oxide, and of Morgan on arterial injection. earthwormexpress.com
25. Laranjo, M., Potes, M.E. and Elias, M. (2019). Role of Starter Cultures on the Safety of Fermented Meat Products. Frontiers in Microbiology 10, 853. doi.org/10.3389/fmicb.2019.00853
26. Polenske, E. (1891). Über den Verlust, welchen das Rindfleisch an Nährwerth durch das Pökeln erleidet, sowie über die Veränderungen salpeterhaltiger Pökellaken. Arbeiten aus dem Kaiserlichen Gesundheitsamte 7. Discussed in van Tonder, E. Polenski. First Science Paper on Meat Curing. EarthwormExpress. earthwormexpress.com
27. Frost, F. (1999). Sausage and Meat Preservation in Antiquity. Greek, Roman, and Byzantine Studies 40(3), 241 to 252. grbs.library.duke.edu
28. Espuña, X., Acosta, L. and Sánchez-Espigares, J.A. (2026). Predicting salt uptake in dry-cured ham using longitudinal modeling and X-ray technology. Meat Science 232, 109979. doi.org/10.1016/j.meatsci.2025.109979
29. Petrova, I., Tolstorebrov, I., Eikevik, T.M. et al. (2015). The influence of temperature modes during salting and resting stages on the mass transfer in dry-cured ham. Proceedings of the 24th IIR International Congress of Refrigeration, Yokohama, paper 335. doi.org/10.18462/iir.icr.2015.0335
30. Sikorski, Z.E. and Sinkiewicz, I. (2015). Principles of smoking. In Toldrá, F. (ed.), Handbook of Fermented Meat and Poultry, 2nd edition. Chichester: Wiley, pp. 39 to 45.
31. Naturhistorisches Museum Wien. Centres of salt production. Text by H. Reschreiter and K. Kowarik. nhm.at
32. Cato, De Agri Cultura 162, and Varro, De Re Rustica 2.4.10 to 2.4.11. Translated by W.D. Hooper and H.B. Ash (1934). Loeb Classical Library. Cambridge, Massachusetts: Harvard University Press. penelope.uchicago.edu
33. Strabo, Geography 4.3.2 and 4.4.3. Translated by H.L. Jones (1923). Loeb Classical Library, volume II. Cambridge, Massachusetts: Harvard University Press. Book 4, chapter 3 and chapter 4
34. Gailtaler Speck g.g.A. Single Document PGI-AT-0192-AM01 (2017) and specification. Registered by Regulation (EC) No 1241/2002, amended by Regulation (EU) 2018/1721. Austrian Patent Office. patentamt.at
35. Tiroler Speck g.g.A. Specification, Austrian file HA 9/2007. Austrian Patent Office. patentamt.at
36. Bundesministerium für Land und Forstwirtschaft, Klima und Umweltschutz, Regionen und Wasserwirtschaft. Gailtaler Speck g.g.A. Register of traditional foods. bmluk.gv.at
37. Encyclopaedia Britannica. Hallstatt culture. britannica.com/topic/Hallstatt-culture
38. Sims-Williams, P. (2020). An Alternative to ‘Celtic from the East’ and ‘Celtic from the West’. Cambridge Archaeological Journal 30(3), 511 to 529. cambridge.org
39. Savić, B., Čandek-Potokar, M. and Škrlep, M. (2024). Dry-Cured Ham, Kraški Pršut, from Heavy Pig Production. A Pilot Study Focusing on the Effect of Ham Weight and Salting. Foods 13(22), 3620. doi.org/10.3390/foods13223620
40. Rzeźnicka, Z., Kokoszko, M. and Jagusiak, K. (2014). Cured Meats in Ancient and Byzantine Sources: Ham, Bacon and Tuccetum. Studia Ceranea 4, 245 to 259. doi.org/10.18778/2084-140X.04.16
41. Meid, W. (2008). Celtic Origins, the Western and the Eastern Celts. Proceedings of the British Academy 154, 177 to 199. thebritishacademy.ac.uk
42. Aspöck, H., Boenke, N., Kofler, W., Oeggl, K., Picher, O. and Stöllner, T. (2007). The Dürrnberg Miners during the Iron Age. New Results by Interdisciplinary Research. In Die unteren Zehntausend. Bochum: Deutsches Bergbau-Museum, pp. 109 to 126. bergbaumuseum.de
43. Naturhistorisches Museum Wien. The La Tène period. nhm.at/hallstatt
44. Kowarik, K., Reschreiter, H., Klammer, J., Grabner, M. and Winner, G. (2015). Umfeld und Versorgung des Hallstätter Salzbergbaus von der Mittelbronzezeit in die Ältere Eisenzeit. In Stöllner, T. and Oeggl, K. (eds), Bergauf Bergab. 10.000 Jahre Bergbau in den Ostalpen. Bochum: Deutsches Bergbau-Museum, pp. 309 to 318.
45. Saliari, K., Pucher, E., Staudt, M. and Goldenberg, G. (2020). Continuities and changes of animal exploitation across the Bronze Age – Iron Age boundary at mining sites in the Eastern Alps. Archaeofauna 29, 77 to 106. doi.org/10.15366/archaeofauna2020.29.005
46. Maixner, F., Sarhan, M.S., Huang, K.D., Tett, A., Schoenafinger, A., Zingale, S. et al. (2021). Hallstatt miners consumed blue cheese and beer during the Iron Age and retained a non-Westernized gut microbiome until the Baroque period. Current Biology 31, 5149 to 5162. doi.org/10.1016/j.cub.2021.09.031
47. Barth, F.E. (2001). Bronzezeitliche Fleischverarbeitung in Hallstatt. Arheološki vestnik 52, 139 to 142. ojs.zrc-sazu.si
48. Boenke, N. (2005). Ernährung in der Eisenzeit. Ein Blick über den Tellerrand. In Karl, R. and Leskovar, J. (eds), Interpretierte Eisenzeiten. Studien zur Kulturgeschichte von Oberösterreich 18. Linz, pp. 241 to 256.
49. Naturhistorisches Museum Wien. Dürrnberg. nhm.at/hallstatt
50. Abd El Karem, M. (2009). Die spätlatènezeitlichen Tierknochenfunde des Simonbauerfeldes auf dem Dürrnberg, Salzburg. Annalen des Naturhistorischen Museums in Wien A 110, 133 to 154, summarising Pucher, E. (1999), Archäozoologische Untersuchungen am Tierknochenmaterial der keltischen Gewerbesiedlung im Ramsautal auf dem Dürrnberg (Salzburg). Dürrnberg-Forschungen 2. Rahden: Leidorf.
51. Pucher, E. (2006). Die Tierknochen aus einem keltischen Bauernhof in Göttlesbrunn (Niederösterreich). Annalen des Naturhistorischen Museums in Wien 107 A, 197 to 220. opac.geologie.ac.at
52. Fremondeau, D., Nuviala, P. and Duval, C. (2017). Pigs and cattle in Gaul. European Journal of Archaeology 20(3), 494 to 509. doi.org/10.1017/eaa.2016.10
53. Athenaeus, Deipnosophistae 14.657e to f (about 200 CE). Translated by C.D. Yonge (1854). London: Henry G. Bohn.
54. Mair, V.H. (2010). The Mummies of East Central Asia. Expedition 52(3). Philadelphia: Penn Museum. penn.museum
55. Mair, V.H. (2016). Ancient Mummies of the Tarim Basin. Discovering Early Inhabitants of Eastern Central Asia. Expedition 58(2). Philadelphia: Penn Museum. penn.museum
56. Barber, E.J.W. (2024). Of Salt Men and Cloth. The Remarkable Textile History Preserved in Eurasian Salt-beds. Sino-Platonic Papers 345, 1 to 26. sino-platonic.org
57. Filipović, D., Meadows, J., Dal Corso, M., Kirleis, W., Alsleben, A., Akeret, Ö. et al. (2020). New AMS 14C dates track the arrival and spread of broomcorn millet cultivation and agricultural change in prehistoric Europe. Scientific Reports 10, 13698. doi.org/10.1038/s41598-020-70495-z
58. Maixner, F., Sarhan, M.S., Huang, K.D., Tett, A., Schoenafinger, A., Zingale, S., Blanco-Míguez, A. et al. (2021). Hallstatt miners consumed blue cheese and beer during the Iron Age and retained a non-Westernized gut microbiome until the Baroque period. Current Biology 31, 5149 to 5162. doi.org/10.1016/j.cub.2021.09.031
59. Xinhua (2023). Primitive bone skates found in Xinjiang. China Daily, 6 March 2023. chinaservicesinfo.com. Chinese report: China News Service, 26 February 2023. chinanews.com.cn
60. Metcalfe, T. (2023). Bronze Age ice skates with bone blades discovered in China. Live Science, 7 March 2023. livescience.com
61. Choyke, A.M. and Bartosiewicz, L. (2005). Skating with Horses. Continuity and Parallelism in Prehistoric Hungary. Revue de Paléobiologie, volume spécial 10, 317 to 326. Bibliographic record with note: schaatshistorie.nl
62. Der steirische Brauch (2024). Wer den Winter liebt. Die Geschichte des Wintersports IV. 18 February 2024. Summary of Choyke and Bartosiewicz 2005, with an image of the runner from Százhalombatta-Földvár by László Bartosiewicz.
63. Poroszlai, I. (2003). Archaeological Park Százhalombatta, Hungary. (Re)Experimental Archaeology 4, 164 to 177. uni.uhk.cz
64. Naturhistorisches Museum Wien. Saltmen Iran. Department of Prehistory, textile research. nhm.at
65. Naturhistorisches Museum Wien. The Man in the Salt. nhm.at/hallstatt
66. Grömer, K., Kern, A., Reschreiter, H. and Rösel-Mautendorfer, H. (eds) (2013). Textiles from Hallstatt. Weaving Culture in Bronze Age and Iron Age Salt Mines. Archaeolingua 29. Budapest: Archaeolingua.
67. Moskvin, A., Grömer, K., Moskvina, M., Kuzmichev, V., Stöllner, T. and Aali, A. (2022). 3D visualization of the 2400 year old garments of Salt Man 4 from Chehrābād, Iran. In Ancient Textile Production from an Interdisciplinary Approach. Cham: Springer, pp. 319 to 338.
68. Long, T., Leipe, C., Jin, G., Wagner, M., Guo, R., Schroeder, O. and Tarasov, P.E. (2018). The early history of wheat in China from 14C dating and Bayesian chronological modelling. Nature Plants 4, 272 to 279. doi.org/10.1038/s41477-018-0141-x
69. Liu, X. and Jiang, J. (2025). A Study of Seima-Turbino Bronze Artifacts Discovered in China. Archaeology, Ethnology and Anthropology of Eurasia 53(1), 64 to 73. doi.org/10.17746/1563-0110.2025.53.1.064-073
70. Librado, P., Khan, N., Fages, A., Kusliy, M.A., Suchan, T., Tonasso-Calvière, L. et al. (2021). The origins and spread of domestic horses from the Western Eurasian steppes. Nature 598, 634 to 640. doi.org/10.1038/s41586-021-04018-9
71. Peters, J., Lebrasseur, O., Irving-Pease, E.K., Paxinos, P.D., Best, J. et al. (2022). The biocultural origins and dispersal of domestic chickens. Proceedings of the National Academy of Sciences 119(24), e2121978119. doi.org/10.1073/pnas.2121978119
72. Best, J., Doherty, S., Armit, I., Boev, Z., Büster, L. et al. (2022). Redefining the timing and circumstances of the chicken’s introduction to Europe and north-west Africa. Antiquity 96(388), 868 to 882. doi.org/10.15184/aqy.2021.90
73. Zhang, F., Ning, C., Scott, A., Fu, Q., Bjørn, R., Li, W., Wei, D. et al. (2021). The genomic origins of the Bronze Age Tarim Basin mummies. Nature 599, 256 to 261. doi.org/10.1038/s41586-021-04052-7
74. Yang, Y., Shevchenko, A., Knaust, A., Abuduresule, I., Li, W., Hu, X., Wang, C. and Shevchenko, A. (2014). Proteomics evidence for kefir dairy in Early Bronze Age China. Journal of Archaeological Science. doi.org/10.1016/j.jas.2014.02.005
75. Liu, Y., Miao, B. et al. (2024). Bronze Age cheese reveals human Lactobacillus interactions over evolutionary history. Cell. doi.org/10.1016/j.cell.2024.08.008
76. Beck, U., Wagner, M., Li, X., Durkin-Meisterernst, D. and Tarasov, P.E. (2014). The invention of trousers and its likely affiliation with horseback riding and mobility. A case study of late 2nd millennium BC finds from Turfan in eastern Central Asia. Quaternary International 348, 224 to 235.
77. Archaeology (2022). Tarim Basin trousers. News report on the study led by Mayke Wagner, 21 February 2022. archaeology.org
78. Good, I. (1995). On the question of silk in pre-Han Eurasia. Antiquity 69(266), 959 to 968. doi.org/10.1017/S0003598X00082491
79. Bender Jørgensen, L. (2013). The question of prehistoric silks in Europe. Antiquity 87(336), 581 to 588. doi.org/10.1017/S0003598X00049140
80. Patterson, N., Isakov, M., Booth, T., Büster, L., Fischer, C.-E. et al. (2022). Large-scale migration into Britain during the Middle to Late Bronze Age. Nature 601, 588 to 594. doi.org/10.1038/s41586-021-04287-4
81. Chin, T. (2013). The Invention of the Silk Road, 1877. Critical Inquiry 40(1), 194 to 219. doi.org/10.1086/673232
82. Encyclopaedia Britannica. Zhang Qian. britannica.com
83. Frachetti, M.D., Smith, C.E., Traub, C.M. and Williams, T. (2017). Nomadic ecology shaped the highland geography of Asia’s Silk Roads. Nature 543, 193 to 198. doi.org/10.1038/nature21696
84. Naturhistorisches Museum Wien. Grave furnishings. Social indicators. nhm.at/hallstatt
85. Frantz, L.A.F., Haile, J., Lin, A.T., Scheu, A., Geörg, C., Benecke, N. et al. (2019). Ancient pigs reveal a near-complete genomic turnover following their introduction to Europe. Proceedings of the National Academy of Sciences 116(35), 17231 to 17238. doi.org/10.1073/pnas.1901169116
86. Encyclopaedia Britannica. Urnfield culture. britannica.com/topic/Urnfield-culture
87. Tabulae Vindolandenses II, tablet 182 (104 to 120 CE). Roman Inscriptions of Britain online. romaninscriptionsofbritain.org
88. Diocletian, Edict on Maximum Prices (301 CE), chapter 4. Translated by A. Kropff (2016). New English translation of the Price Edict of Diocletianus, version 2.1. skidmore.edu
89. Capitulare de villis (about 800 CE). In Robinson, J.H. (ed.) (1904). Readings in European History, volume I. Boston: Ginn and Company, pp. 137 to 139. Internet Medieval Sourcebook, Fordham University. sourcebooks.fordham.edu
90. Seetah, K. (2007). The Middle Ages on the Block. Animals, Guilds and Meat in the Medieval Period. In Pluskowski, A. (ed.), Breaking and Shaping Beastly Bodies. Animals as Material Culture in the Middle Ages. Oxford: Oxbow Books, pp. 18 to 31. doi.org/10.2307/j.ctvh1dqx6.5
91. Haldane, J. (1901). The red colour of salted meat. Journal of Hygiene 1(1), 115 to 122.
92. Naturhistorisches Museum Wien. Dürrnberg. Text by T. Stöllner and S. Moser. nhm.at
93. Ministère de la Culture, France. The Celtic saltworks at Marsal (Moselle). Research programme directed by L. Olivier, Musée d’Archéologie nationale. archeologie.culture.gouv.fr
94. Ministère de la Culture, France. Acy-Romance. Spit-roasting and curing pork. archeologie.culture.gouv.fr
95. Wilson, A. (2007). Quantification of fish-salting infrastructure capacity in the Roman world. Oxford Roman Economy Project, working paper. Citing Sanquer, R. and Galliou, P. (1970), Garum, sel et salaisons en Armorique gallo-romaine, Gallia 30, 199 to 223. oxrep.classics.ox.ac.uk
96. Guerra-Doce, E., Delibes de Castro, G., Abarquero-Moras, F.J., del Val-Recio, J.M. and Palomino-Lázaro, Á.L. (2011). The Beaker salt production centre of Molino Sanchón II, Zamora, Spain. Antiquity 85(329), 805 to 818. doi.org/10.1017/S0003598X00068320
97. Sherlock, S.J. (2021). Early Neolithic salt production at Street House, Loftus, north-east England. Antiquity 95(381), 648 to 669. doi.org/10.15184/aqy.2021.25
98. Historic England. Multi-period salt production remains in Droitwich. List entry 1020256. historicengland.org.uk
99. Historic England. Roman saltern 750m north west of Maydays Farm, West Mersea. List entry 1020490. historicengland.org.uk
100. Madgwick, R., Lamb, A.L., Sloane, H., Nederbragt, A.J., Albarella, U., Parker Pearson, M. and Evans, J.A. (2019). Multi-isotope analysis reveals that feasts in the Stonehenge environs and across Wessex drew people and animals from throughout Britain. Science Advances 5(3), eaau6078. doi.org/10.1126/sciadv.aau6078
101. Wright, E., Viner-Daniels, S., Parker Pearson, M. and Albarella, U. (2014). Age and season of pig slaughter at Late Neolithic Durrington Walls (Wiltshire, UK) as detected through a new system for recording tooth wear. Journal of Archaeological Science 52, 497 to 514. doi.org/10.1016/j.jas.2014.09.009
102. Olalde, I., Brace, S., Allentoft, M.E. et al. (2018). The Beaker phenomenon and the genomic transformation of northwest Europe. Nature 555, 190 to 196. doi.org/10.1038/nature25738
103. Harding, A. (2013). Salt in Prehistoric Europe. Leiden: Sidestone Press, pp. 11, 13, 30 and 38. sidestone.com
104. Heggarty, P., Anderson, C. and Scarborough, M. (eds). IE-CoR, Indo-European Cognate Relationships database. Cognate set 283, meaning salt, revised by M. Scarborough. Leipzig: Max Planck Institute for Evolutionary Anthropology. iecor.clld.org/cognatesets/283
105. Oxford University Press (2025). The salt of the earth. The Oxford Etymologist, OUPblog. blog.oup.com
106. Duval, C., Fremondeau, D., Lepetz, S. and Horard-Herbin, M.P. (2016). L’élevage du porc. Un savoir-faire gaulois? Revue Archéologique de Picardie 30, 583 to 596.
107. Ministère de la Culture, France. Entremont. Animal husbandry. archeologie.culture.gouv.fr
108. Méniel, P. (2009). Histoire de l’alimentation carnée dans le village gaulois d’Acy-Romance (IIe et Ier siècles av. J.C., Ardennes, France). Paper at From Cooking to Eating. IV Meeting of Economy in the 1st Millennium BC, Caudete de las Fuentes, 22 to 23 October 2009. uv.es. Fauna monograph: Méniel, P. (1998). Les animaux et l’histoire d’un village gaulois. Fouilles 1989 to 1997. Mémoire de la Société Archéologique Champenoise 14.
109. Ministère de la Culture, France. The Gauls of Acy-Romance. Scientific director Bernard Lambot (CNRS). archeologie.culture.gouv.fr
110. Ministère de la Culture, France. Acy-Romance. Men and animals. archeologie.culture.gouv.fr
111. Ministère de la Culture, France. Acy-Romance. Food for the dead. archeologie.culture.gouv.fr
112. Strabo, Geography 3.4.11. Translated by H.L. Jones (1923). Loeb Classical Library, volume II. Cambridge, Massachusetts: Harvard University Press. penelope.uchicago.edu
113. Gilligan, N. Salt from Seaweed? An Experimental Archaeology Perspective on Salt in Early Medieval Ireland. Feast Journal. With citations of F. Kelly, Early Irish Farming, pp. 336 and 341, and of the law tract Uraicecht Becc. feastjournal.co.uk
114. Kinory, J. (2011). Salt production, distribution and use in the British Iron Age. DPhil thesis, University of Oxford. doi.org/10.5287/ora-2red2oxgy
115. The National Archives (United Kingdom). Domesday Book. Education resource pack. nationalarchives.gov.uk
116. Ärzte Zeitung. 700 Jahre Nürnberger Bratwurst. Report with statements by Peter Fleischmann, director of the Staatsarchiv Nürnberg. aerztezeitung.de
117. Museen der Stadt Nürnberg (2014). 9 cm Nürnberg. Eine Kulturgeschichte der Nürnberger Bratwurst. Exhibition at the Stadtmuseum Fembohaus, 24 September 2014 to 29 March 2015. museen.nuernberg.de
118. European Union (2011). Publication of an amendment application. Thüringer Rostbratwurst, EC No DE-PGI-0105-0223-09.02.2011. Official Journal of the European Union C 310, 22 October 2011, 14 to 16. eur-lex.europa.eu
119. Bundesministerium für Land- und Forstwirtschaft, Klima- und Umweltschutz, Regionen und Wasserwirtschaft, Austria. Traditionelle Lebensmittel. Frankfurter / Wiener Würstel. bmluk.gv.at
120. Government Communication Office of the Republic of Slovenia. The Carniolan sausage. slovenia.si
121. Polybius, Histories 2.15. Translated by W.R. Paton (1922). Loeb Classical Library, volume I. Cambridge, Massachusetts: Harvard University Press. penelope.uchicago.edu
122. Leeds University Library, Brotherton Collection MS 1, Book of Hours (1424), calendar, fol. 11r (November, a man knocking acorns from oak trees) and fol. 12r (December, a man slaughtering a pig). digital.library.leeds.ac.uk. See also Laumonier, L. (2022). Medieval calendars and the labours of the months. Medievalists.net.
123. Larkin, D. (2009). The Medieval Garden Enclosed. Pigs and Pannage. New York: The Metropolitan Museum of Art. metmuseum.org
124. Marzano, A. (2024). Marine salt production in the Roman world. The salinae and their ownership. Quaternary Science Reviews 336, 108776. doi.org/10.1016/j.quascirev.2024.108776
125. Encyclopaedia Britannica. Charlemagne. britannica.com/biography/Charlemagne
126. Capitularia. Edition der fränkischen Herrschererlasse. Capitulare de villis [BK 32], with the dates proposed by its editors. University of Cologne. capitularia.uni-koeln.de
127. Verhulst, A. (2002). The Carolingian Economy. Cambridge: Cambridge University Press, chapter 9.
128. Herzog August Bibliothek Wolfenbüttel. Cod. Guelf. 254 Helmst. Description following Härtel, H. (2012), Katalog der mittelalterlichen Helmstedter Handschriften I. Wiesbaden, pp. 321 to 322. diglib.hab.de
129. Schneider, R. (ed.) (1968). Das Frankenreich. Kapitularien. Göttingen. Capitulare de villis, chapter 34. Latin text online at tha.de
130. Ibn Battuta, Travels in Asia and Africa 1325 to 1354. Journey to Taghaza in 1352. Translated and edited by H.A.R. Gibb (1929). London: Broadway House. faculty.tnstate.edu
131. Food and Agriculture Organization of the United Nations (1990). Manual on simple methods of meat preservation. FAO Animal Production and Health Paper 79. Rome: FAO. fao.org
132. Food and Agriculture Organization of the United Nations. Livestock keeping in urban areas, chapter 6, Product processing and waste management, citing Heinz (FAO 1995). fao.org
133. Encyclopaedia Britannica, 11th edition (1911). Hottentots. en.wikisource.org
134. van Tonder, E. (2018). Salt and the Ancient People of Southern Africa. EarthwormExpress. With quotations from O.F. Mentzel, Beschreibung des Vorgebirges der Guten Hoffnung (Description of the Cape of Good Hope, 1785 and 1787), A. Sparrman, A Voyage to the Cape of Good Hope (1786), and I. Schapera, The Khoisan Peoples of South Africa (1930). earthwormexpress.com
135. van Tonder, E. (2017). Saltpeter, Horse Sweat and Biltong. The origins of South Africa’s national food. EarthwormExpress. With quotations from A. Sparrman, A Voyage to the Cape of Good Hope (1786), p. 313, from I. Schapera (1930), and with oral accounts from Eleanor Muller and from an interview of 2019. earthwormexpress.com
136. Schapera, I. (1930). Culture of the Hottentots. In The Khoisan Peoples of South Africa: Bushmen and Hottentots. London: Routledge, pp. 221 to 418. Quoted from reference 53. ehrafworldcultures.yale.edu
137. Alpern, S.B. (2008). Exotic Plants of Western Africa: Where They Came From and When. History in Africa 35, 63 to 102. doi.org/10.1353/hia.0.0018
138. Agricultural Biodiversity Weblog (2017). Peanuts and world history. Summary of the work of G.E. Brooks and S.B. Alpern. agro.biodiver.se
139. Majola, N.G., Gerrano, A.S. and Shimelis, H. (2021). Bambara Groundnut (Vigna subterranea [L.] Verdc.) Production, Utilisation and Genetic Improvement in Sub-Saharan Africa. Agronomy 11, 1345. doi.org/10.3390/agronomy11071345
140. Universität Innsbruck (2020). Tierknochen: Ein Blick in die Vergangenheit (Animal Bones: A Look into the Past). Press release on reference 25. uibk.ac.at
141. Amills, M., Ramírez, O., Galman-Omitogun, O. and Clop, A. (2013). Domestic Pigs in Africa. African Archaeological Review 30(1), 73 to 82. doi.org/10.1007/s10437-012-9111-2
142. Herodotus, Histories 2.47. Translated by A.D. Godley (1920). Loeb Classical Library, volume I. Cambridge, Massachusetts: Harvard University Press. penelope.uchicago.edu
143. Zhou, G.-H. and Zhao, G.-M. (2012). History and heritage of Jinhua ham. Animal Frontiers 2(4), 62 to 67. doi.org/10.2527/af.2012-0063
144. Milburn, O. (2025). Cooking meat in ancient China: luan 臠, zi 胾, and the origins of the kebab. Journal of the Royal Asiatic Society 35(4), 1051 to 1066. Cites the commentary of Zheng Xuan on the Zhouli and the Shiming. doi.org/10.1017/S1356186325101247
145. 賈思勰 (Jiǎ Sīxié) (about 544 CE). 齊民要術 (Qímín yàoshù, Essential Techniques for the Welfare of the People). Book 8, chapters 74 (作魚鮓) and 75 (脯腊); book 9, chapters 80 (炙法, 灌腸法) and 90 (煮膠). Chinese Wikisource edition.
146. Wissler, C. (1910). Material Culture of the Blackfoot Indians. Anthropological Papers of the American Museum of Natural History 5(1). New York. core.tdar.org
147. Saraceni, J.E. (2017). Pemmican production camp found in the Northern Plains. Archaeology, 19 April 2017. Report on the work of B. Bethke and M.N. Zedeño, University of Arizona. archaeology.org
148. Larson, G., Dobney, K., Albarella, U., Fang, M., Matisoo-Smith, E., Robins, J., Lowden, S., Finlayson, H., Brand, T., Willerslev, E., Rowley-Conwy, P., Andersson, L. and Cooper, A. (2005). Worldwide phylogeography of wild boar reveals multiple centers of pig domestication. Science 307, 1618 to 1621. doi.org/10.1126/science.1106927
149. Larson, G., Liu, R., Zhao, X., Yuan, J., Fuller, D., Barton, L., Dobney, K. et al. (2010). Patterns of East Asian pig domestication, migration, and turnover revealed by modern and ancient DNA. Proceedings of the National Academy of Sciences 107, 7686 to 7691.
150. Larson, G., Albarella, U., Dobney, K., Rowley-Conwy, P., Schibler, J., Tresset, A., Vigne, J.D. et al. (2007). Ancient DNA, pig domestication, and the spread of the Neolithic into Europe. Proceedings of the National Academy of Sciences 104(39), 15276 to 15281. doi.org/10.1073/pnas.0703411104
151. 张仲葛 (Zhāng Zhònggě), 张晓岚 (Zhāng Xiǎolán) and 李锦钰 (Lǐ Jǐnyù) (1994). 中国猪的优良种性及其对世界养猪业的贡献 (Zhōngguó zhū de yōuliáng zhǒngxìng jí qí duì shìjiè yǎngzhū yè de gòngxiàn, The superior traits of Chinese pigs and their contribution to world pig farming). 自然资源学报 (Zìrán zīyuán xuébào, Journal of Natural Resources) 9(1), 1 to 8. doi.org/10.11849/zrzyxb.1994.01.001
152. van Tonder, E. (2019). Kolbroek. Chinese, New Zealand, and English Connections. EarthwormExpress. earthwormexpress.com
153. van Tonder, E. Chapter 13.15. The English Pig with links to the Kolbroek and Kunekune. Bacon and the Art of Living. EarthwormExpress. earthwormexpress.com
154. Giuffra, E., Kijas, J.M.H., Amarger, V., Carlborg, Ö., Jeon, J.T. and Andersson, L. (2000). The origin of the domestic pig. Independent domestication and subsequent introgression. Genetics 154(4), 1785 to 1791. doi.org/10.1093/genetics/154.4.1785
155. Chen, H., Huang, M., Yang, B., Wu, Z., Deng, Z., Hou, Y., Ren, J. and Huang, L. (2020). Introgression of Eastern Chinese and Southern Chinese haplotypes contributes to the improvement of fertility and immunity in European modern pigs. GigaScience 9(3), giaa014. doi.org/10.1093/gigascience/giaa014
156. White, S. (2011). From globalized pig breeds to capitalist pigs. A study in animal cultures and evolutionary history. Environmental History 16(1), 94 to 120. doi.org/10.1093/envhis/emq143
157. Fang, M. and Andersson, L. (2006). Mitochondrial diversity in European and Chinese pigs is consistent with population expansions that occurred prior to domestication. Proceedings of the Royal Society B 273(1595), 1803 to 1810. doi.org/10.1098/rspb.2006.3514
158. Bosse, M., Madsen, O., Megens, H.J., Frantz, L.A.F., Paudel, Y., Crooijmans, R.P.M.A. and Groenen, M.A.M. (2015). Hybrid origin of European commercial pigs examined by an in-depth haplotype analysis on chromosome 1. Frontiers in Genetics 5, 442. doi.org/10.3389/fgene.2014.00442
159. Bosse, M., Megens, H.J., Frantz, L.A.F., Madsen, O., Larson, G., Paudel, Y. et al. (2014). Genomic analysis reveals selection for Asian genes in European pigs following human-mediated introgression. Nature Communications 5, 4392. doi.org/10.1038/ncomms5392
160. Clop, A., Amills, M., Noguera, J.L., Fernández, A., Capote, J., Ramón, M.M., Kelly, L., Kijas, J.M.H., Andersson, L. and Sànchez, A. (2004). Estimating the frequency of Asian cytochrome B haplotypes in standard European and local Spanish pig breeds. Genetics Selection Evolution 36(1), 97 to 104. doi.org/10.1051/gse:2003053
161. Wilkinson, S., Lu, Z.H., Megens, H.J., Archibald, A.L., Haley, C., Jackson, I.J., Groenen, M.A.M., Crooijmans, R.P.M.A., Ogden, R. and Wiener, P. (2013). Signatures of diversifying selection in European pig breeds. PLoS Genetics 9(4), e1003453. doi.org/10.1371/journal.pgen.1003453
162. Yang, B., Cui, L., Perez-Enciso, M., Traspov, A., Crooijmans, R.P.M.A., Zinovieva, N. et al. (2017). Genome-wide SNP data unveils the globalization of domesticated pigs. Genetics Selection Evolution 49, 71. doi.org/10.1186/s12711-017-0345-y
163. Marincs, F., Molnár, J., Tóth, G., Stéger, V. and Barta, E. (2013). Introgression and isolation contributed to the development of Hungarian Mangalica pigs from a particular European ancient bloodline. Genetics Selection Evolution 45, 22. doi.org/10.1186/1297-9686-45-22
164. Bühler, R. Das Schwäbisch-Hällische Landschwein. Die älteste und traditionsreichste Schweinerasse Deutschlands. Breed history, pp. 26 to 29. uni-hohenheim.de
165. van Tonder, E. and van Tonder-Berger, C. Pressed Meat. A Chinese Technology Set. EarthwormExpress. With citations of the Qimin Yaoshu, books 8 and 9, and of the FAO description of pastirma. earthwormexpress.com
166. Plautus, Captivi, lines 850, 903 and 908 (before 184 BCE). Latin text, The Latin Library. thelatinlibrary.com. See also Rzeźnicka, Z., Kokoszko, M. and Jagusiak, K. (2014). Cured Meats in Ancient and Byzantine Sources. Ham, Bacon and Tuccetum. Studia Ceranea 4, 245 to 259. doi.org/10.18778/2084-140X.04.16
167. 周易 (Zhōuyì, Book of Changes), hexagram 噬嗑 (Shìhé). Chinese Wikisource edition. zh.wikisource.org
168. 論語 (Lúnyǔ, Analects of Confucius) 7.7. Chinese Wikisource edition. zh.wikisource.org
169. 周禮 (Zhōulǐ, Rites of Zhou), 天官 (Tiānguān, Offices of Heaven), 腊人 (xīrén). Quoted at zdic.net
170. Cucchi, T., Hulme-Beaman, A., Yuan, J. and Dobney, K. (2011). Early Neolithic pig domestication at Jiahu, Henan Province, China. Journal of Archaeological Science 38(1), 11 to 22. doi.org/10.1016/j.jas.2010.07.024
171. United States Food and Drug Administration (1984). Water Activity (aw) in Foods. Inspection Technical Guide 39. fda.gov
172. Sandman, E. (1999). Solubility of myosin and the binding quality of meat products. Proceedings of the 45th International Congress of Meat Science and Technology, pp. 237 to 241. digicomst.ie
173. Clark, K.A., Ikram, S. and Evershed, R.P. (2013). Organic chemistry of balms used in the preparation of pharaonic meat mummies. Proceedings of the National Academy of Sciences 110(51), 20392 to 20395. doi.org/10.1073/pnas.1315160110
174. Herodotus, Histories 2.77 and 2.86. Translated by G.C. Macaulay (1890). Internet Sacred Text Archive. Book 2, chapter 77 and chapter 86
175. van Tonder, E. Chapter 17.01. Finally. From Mummies to Nitrosamines. Bacon & the Art of Living, EarthwormExpress. With citations of V. Wohl and of Binkerd, E.F. and Kolari, O.E. (1975). The history and use of nitrate and nitrite in the curing of meat. Food and Cosmetics Toxicology 13, 655 to 661. earthwormexpress.com
176. van Tonder, E. (2018). Honey. Powerful preserving and healing power. EarthwormExpress. Citing Aufderheide, A.C. (2003). The Scientific Study of Mummies. Cambridge: Cambridge University Press, p. 45. earthwormexpress.com
177. Ikram, S. (2008). Meat Preservation in Ancient Egypt. In Selin, H. (ed.), Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures. Dordrecht: Springer. See also Ikram, S. (1995). Choice Cuts: Meat Production in Ancient Egypt. Orientalia Lovaniensia Analecta 69. Leuven: Peeters. doi.org/10.1007/978-1-4020-4425-0_8752
178. Jones, J., Higham, T.F.G., Oldfield, R., O’Connor, T.P. and Buckley, S.A. (2014). Evidence for prehistoric origins of Egyptian mummification in Late Neolithic burials. PLoS ONE 9(8), e103608. doi.org/10.1371/journal.pone.0103608
179. Nerlich, A.G., Falter, J. and Zink, A. (2005). Why did the Egyptians use natron for artificial embalming? An experimental study on organ mummification. Journal of Biological Research 80(1). doi.org/10.4081/jbr.2005.10174
180. Megaw, V., Morgan, G. and Stöllner, T. (2000). Ancient salt-mining in Austria. Antiquity 74(283), 17 to 18. doi.org/10.1017/S0003598X0006600X
181. UNESCO World Heritage Centre (2021). Settlement and Artificial Mummification of the Chinchorro Culture in the Arica and Parinacota Region. whc.unesco.org
182. Pausanias, Description of Greece 1.7.2. Translated by W.H.S. Jones and H.A. Ormerod (1918). Loeb Classical Library. perseids.org
183. The Metropolitan Museum of Art. Painted limestone grave stele of a Galatian soldier, Alexandria, 3rd century BCE, accession 04.17.5. metmuseum.org
184. Carey, J. (1993). A New Introduction to Lebor Gabála Érenn. London: Irish Texts Society. celt.ucc.ie
185. Gad, Y.Z., Hassan, N.A., Mousa, D.M. et al. (2020). Maternal and Paternal Lineages in King Tutankhamun’s Family. In Kamrin, J. et al. (eds), Guardian of Ancient Egypt. Studies in Honor of Zahi Hawass, volume I. Prague: Charles University, pp. 497 to 518.
186. Varberg, J., Gratuze, B. and Kaul, F. (2015). Between Egypt, Mesopotamia and Scandinavia. Late Bronze Age glass beads found in Denmark. Journal of Archaeological Science 54, 168 to 181. doi.org/10.1016/j.jas.2014.11.036
187. Scott, W.J. (1957). Water relations of food spoilage microorganisms. Advances in Food Research 7, 83 to 127.
188. Martuscelli, M., Lupieri, L., Sacchetti, G., Mastrocola, D. and Pittia, P. (2017). Prediction of the salt content from water activity analysis in dry-cured ham. Journal of Food Engineering 200, 29 to 39.
189. van Tonder, E. and van Tonder, K. (2025). Bone Collagen. From Ancient Broths to Modern Food Science. EarthwormExpress. Citing Shoulders and Raines (2009). earthwormexpress.com
190. Shoulders, M.D. and Raines, R.T. (2009). Collagen structure and stability. Annual Review of Biochemistry 78, 929 to 958.
191. Shurtleff, W. and Aoyagi, A. History of Tofu. Lafayette, California: Soyinfo Center. soyinfocenter.com
192. Qin, Y., Li, Y., Bao, H., Liu, F., Hou, K., Wan, D. and Zhang, C. (2012). Massive atmospheric nitrate accumulation in a continental interior desert, northwestern China. Geology 40(7), 623 to 626. doi.org/10.1130/G32953.1
193. van Tonder, E. (2017). Nitrate salt’s epic journey. From Turfan in China, through Nepal to North India. EarthwormExpress. earthwormexpress.com
194. van Tonder, E. Chapter 12.06.1. From Sea to Deserts. Sal Ammoniac Predating Saltpetre. Bacon and the Art of Living. EarthwormExpress, citing Laufer, B. (1919), Sino-Iranica. earthwormexpress.com
195. van Tonder, E. (2021). The Turfan Depression links with the Black Sea Region. EarthwormExpress.
196. Hansen, V. (2005). The Impact of the Silk Road Trade on a Local Community. The Turfan Oasis, 500 to 800. In de la Vaissière, É. and Trombert, É. (eds), Les Sogdiens en Chine. Paris: École française d’Extrême-Orient, pp. 283 to 310. history.yale.edu
197. 隋書 (Suí shū, Book of Sui, compiled 636 CE), chapter 83, Western Regions, entries for Kucha and Kang. zh.wikisource.org
198. Butler, A. and Moffett, J. A Chinese Medieval Treatment for Angina. International Dunhuang Project, British Library. idp.bl.uk. See also Lo, V. and Cullen, C. (eds) (2005). Medieval Chinese Medicine. The Dunhuang Medical Manuscripts. London: RoutledgeCurzon.
199. Schröder, O., Wagner, M., Wutke, S. et al. (2016). Ancient DNA identification of domestic animals used for leather objects in Central Asia during the Bronze Age. The Holocene 26(10), 1722 to 1729. doi.org/10.1177/0959683616641741
200. Wang, Y., Monteith, F. et al. (2023). Scientific Reports 13, 4338. Animal husbandry in the eastern Tianshan in the first millennium BCE. doi.org/10.1038/s41598-023-31489-9
201. Millward, J.A. (2007). Eurasian Crossroads. A History of Xinjiang. New York: Columbia University Press.
202. Leitner, C., Neubauer, F., Genser, J., Borojević Šoštarić, S. and Rantitsch, G. (2013). 40Ar/39Ar ages of crystallization and recrystallization of rock forming polyhalite in Alpine rocksalt deposits. International Journal of Earth Sciences 102, 813 to 829. doi.org/10.1007/s00531-012-0836-6
203. Cressy, D. (2013). Saltpeter. The Mother of Gunpowder. Oxford: Oxford University Press.
204. van Tonder, E. (2024). Uncovering the Link Between Celtic Curing Traditions and Early Monastic Practices in Austria. A Journey from Hallstatt to the Benedictine Abbey. EarthwormExpress, 29 September 2024. earthwormexpress.com