Chapter 11.03: The Direct Addition of Nitrites to Curing Brines – the Master Butcher from Prague

Bacon & the Art of Living 1

Introduction to Bacon & the Art of Living

The quest to understand how great bacon is made takes me around the world and through epic adventures. I tell the story by changing the setting from the 2000s to the late 1800s when much of the technology behind bacon curing was unraveled. I weave into the mix beautiful stories of Cape Town and use mostly my family as the other characters besides me and Oscar and Uncle Jeppe from Denmark, a good friend and someone to whom I owe much gratitude! A man who knows bacon! Most other characters have a real basis in history and I describe actual events and personal experiences set in a different historical context.

The cast I use to mould the story into is letters I wrote home during my travels.

The Direct Addition of Nitrites to Curing Brines – the Master Butcher from Prague

September 1959

Dear Tristan,

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Prague, photo by Dawie Hyman

I received your previous mail with great excitement. Your account of Henry Hudson’s exploration around the New York area, what became known as Hudson Bay and the Hudson River is riveting! I am so glad you go to exhibitions such as these! It broadens our horizons ! You know that we get to read newspapers from around the world in our Cape Town library. Last Monday I went into the city and spent the day at the library and the archives. I made this clipping from the Troy Record for you advertising the exhibition you visited in Amsterdam.

From the Troy Record, Troy, New York, 27 March 1959.

The story is epic. How an Englishman was employed by the Dutch East Indian Company to find the rumoured northeast passage to Cathay via a route above the arctic circle. He landed in North America in 1609 where he explored the regions around New York looking for a Northwest Passage. His exploits became the basis for a Dutch Colony that was later established here and the Hudson River was named after him.

He was back in 1611, this time on behalf of the English East Indian Company but his voyage ended in a mutiny by his crew when, after a long winter, they were eager to return to Europe when Hudson wanted to press on with his trip. In the end, Hudson, his teenage son John, and seven crewmen (all men who were either sick and infirm or loyal to Hudson) were forced into a small shallop (a name used for several types of boats and small ships) and left behind. The small vessel tried to keep up with the large ship but they hoisted another sail and left the small boat behind. Hudson, his son and the others left behind were never seen again.

It can, on the one hand not imagine a more desperate situation than to be left behind with your son when he will either see his dad dying at the hand of hostile locals or by the challenges of nature. If the son did not see his father suffering these, it was surely the father who saw his son dying. Yet, I can not help but notice that he took his son with him on his exploration! That reminds me us!

The events transpired in the 1600s which is where I want to pick up the story of the art of bacon. I am very thankful that I am able, through the technology of writing, drawings, and pictures, to share my adventure with you and your sister. I enjoy the fact that my voyage of discovery involves all the senses. It challenges and engages my entire being, mind, and soul! The quest is not only bacon but life itself and the crown of life most certainly, is not the places I visited and the many things I learned, but Minette! How thankful am I that we walk this amazing path together and with you guys!

Meat Curing: 1600 to 1910

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Prague Breakfast by Dawie Hyman

Before the 1600s meat preservation was done with salt only. Colour in meat was important from antiquity because a reddish appearance denotes freshness. People looked for ways to manipulate meat colour for a long time, probably since meat was sold or traded. In the 1600s vegetable dyes were used to bolster colour. (The history of curing) A few people added a little bit of saltpeter (potassium nitrate) to the salt for “cured colour development.” This practice gained momentum from the year 1700. By 1750, the trend turned into the norm, being practiced almost universally as salpeter became universally available and the quality and purity improved. During the 1800s sugar was added to the mix. This, with the exception of ascorbic acid and phosphates that have been added since the mid-1900s, is very much the same process as we follow today. (Ladislav NACHMÜLLNER vs The Griffith Laboratories)

On 7 May 1868, Dr. Arthur Gamgee from the University of Edinburgh, brother of the famous veterinarian, Professor John Gamgee (who contributed to the attempt to find ways to preserve whole carcasses during a voyage between Australia and Britain), published a groundbreaking article entitled, “On the action of nitrites on the blood.” He observed the colour change brought about by nitrite. He wrote, “The addition of … nitrites to blood … causes the red colour to return…” (Gamgee, A; 1867 – 1868; Vol. 16, 339-342) Over the next 30 years, it would be discovered that it is indeed nitrites responsible for curing and not the nitrates added as saltpeter.

It fell upon a German researcher, Dr. Ed Polenske (1849-1911), working for the Imperial Health Office in Germany, to make the first discovery that would lead to a full understanding of the curing action. He prepared a brine to cure meat and used only salt and saltpeter (nitrates). When he tested it a week later, it tested positive for nitrites. (Polenske. E. 1891)

The question is where did the nitrites come from if he did not add it to the brine, to begin with. He correctly speculated that this was due to nitrate being converted by microbial action into nitrite. He published in 1891. (Polenske. E. 1891)
Karl Bernhard Lehmann and Karl Kißkalt discovered in 1899 that nitrite is responsible for the reddish color of dry-cured meat. It was John Scott Haldane who showed in a 1901 article that the cured meat colour is due to a nitrosylheme complex. (Concerning the direct addition of nitrite to curing brine) (Hoagland, Ralph. 1914)[1] The heme part of the meat protein is where the colour is generated through the presence of an Fe ion and nitrolsyl refers to a non-organic compounds containing the NO group. In the protein, nitric oxide is bound to the Fe ion through the nitrogen atom. Therefore the term, nitrosylheme complex.

The change of nitrate into nitrite through bacterial action takes weeks. If a salt, like sodium nitrite, is used instead of saltpeter, curing is accomplished in days or even hours (if a heating step is applied to the meat before it is smoked).

The only aspect in curing that is time-consuming is however not the bacterial reduction of nitrates to nitrites. The change from nitrite into a form that reacts with the meat protein and produce the nitric oxide coupling with the Fe ion is also not instantaneous. The rate of reaction is slow.[2] It is not like mixing sugar into coffee. An analogy is if you put sugar in your coffee and have to wait twelve hours and reheat it in the microwave before you can taste sweetness.

When the brine enters the meat, the anion CodeCogsEqn (17) is formed and a very small amount of nitrite (less than 1% of the total nitrite) forms the neutral nitrous acid (CodeCogsEqn (19)). It is nitrous acid that is responsible for the formation of nitrosating compounds which is the ultimate reaction of joining nitric oxide to an organic compound, in this case, the myoglobin protein (resulting in a nitroso derivative). (Sebranek, J. and Fox, J. B. Jn.. 1985)

The first step in the reaction sequence of creating such a link between myoglobin and nitric oxide is the formation of nitrous acid (HNO2). From nitrous acid, the neutral radical, nitric oxide is formed directly as well as a variety of nitrosating species or molecules that create such a nitrite-oxygen pair of atoms to link to an organic structure like a protein. [3] [4] (Sebranek, J. and Fox, J. B. Jn.. 1985)

This reaction takes time and its rate is dependent on the pH of the meat it is injected into, the temperature of the meat and the brine and the concentration of nitrite. Curing then happens when the nitric oxide reacts with iron which is part of the meat proteins, myoglobin. [1]

The concentration of nitrous acid is very low in meats. This means that the potential for nitrite to change into nitric oxide to react with the meat protein is very low. In general, nitrite is readily reduced by endogenous reductants in the meat to form nitric oxide. (Toldr, F.; 2010: 180) [5] The reduction of nitrous acid can be sped up by adding a “reducing agent” to the brine mix. (Pegg, B. R. and Shahidi, F.; 2000: 39) (the presence of table salt also speeds up the conversion of nitric oxide, but this matter is for another article.

One such reducing agent, introduced to brine cures in the 1800s, is sugar. [6] Sugar was added originally to reduce the salty taste of the meat. Curers noticed that if sugar is added with saltpeter to the brine mix, the meat cures slightly faster and with better colour development. (The history of curing) In the 1920s, ascorbate or its isomer, erythorbate became the magical reducing agent [7], but this too is the subject for a future letter.

If saltpeter is used as principal curing ingredient, adding sugar favours the proliferation of bacteria that reduces nitrate to nitrite. It, therefore, speeds up the curing process. Better colour development is due to the action of reducing sugars (such as brown sugar) to create a reducing environment in the meat which encourages the reduction of nitrous acid to nitric oxide (Kim-Shapiro, D. B. et al. 2006). [6] (The history of curing)

Investigating Two Sources of Nitrite’s

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Prague Supper by Dawie Hyman

This was then the understanding of meat curing by the beginning of the 1900s. Scientists knew that adding nitrite directly to the meat would dramatically speed up the curing process, but working out how to do it and navigating through the complex maze of public perception and legal restraints would be another matter altogether.

The Irish and later the Danes took the development where nitrites are directly applied to curing, in one very particular direction. They invented the “mother brine” cure. The concept of re-using the old brine and meat juices was a well-known practice in many regions of the world from early on. Butchers worked out that it speeds up curing, even long before the term nitrite was coined. It was the Irish who invented a system to exploit the mother-brine approach on an industrial scale. The Danes got the technology from Ireland and I, after studying under Uncle Jeppe and Andreas in Denmark taught the system to John Harris in Calne. They called it tank curing which is a method of allowing bacteria to reduce saltpeter to nitrites and the nitrites to be added back into bacon brine after it was boiled to kill the bacteria. The net result is that nitrites were produced through bacterial means and the nitrites were used to cure the meat much quicker than could ever be done with saltpeter alone. (The Mother Brine and C & T Harris and their Wiltshire bacon cure)

There was, however another readily available source of nitrites which became the focal point of meat curers in Germany, Austria, Hungary and in the USA. Nitrites were already being used in a large, industrial process since the end of the 1800s in the form of sodium nitrite. This made it generally available.

Sodium nitrite was used in the production of azo dyes. It was available in every country and city where there was a large dye industry. This was part of the new and booming new industry of coal-tar dyes. The late 1800s and early 1900s was the birth of the age of chemistry and chemical synthesis, a development that directly resulted from the dye industry. (Concerning Chemical Synthesis and Food Additives)

There were early scientific flirtations with the use of sodium nitrite in meat. A laboratory in Germany, founded by C. R. Fresenius, records in 1848 experiment with sodium nitrite to preserve meat. (Ladislav NACHMÜLLNER vs The Griffith Laboratories)

An article appeared in the Sydney Morning Herald on 1 March 1870 where it lists the methods of preserving canned meat in use at that time. Included in the list of “antiseptic agents” are “sulfurous and nitrous acids, sulphites and nitrite. (It also lists sodium and “other substances having a special affinity for oxygen.”) It was explained that “these agents are not applied to meat itself, but are used simply to absorb oxygen unavoidably left within the tins and pores of the meat.” As far as the preservation of fresh meat is concerned, the world saw it as a race between the use of chemicals or cold. (Sydney Morning Herald, 1 March 1870, p4)

PRAGUE 1800 – 1920 – Food innovation, industrial leadership and the availability of nitrite

old-prague-logansport_pharos_tribune_sat__oct_19__1895_Prague, Logansport Pharos-Tribune, 19 Oct. 1895

Germany’s neighbor and ally in World War One, the Austro-Hungarian Empire with the key cities of Prague, Vienna, and Budapest, in the late 1800s and early 1900s led the world in many respects in matters pertaining to science and technology.  In Bohemia and regions surrounding Prague, the industries were leading Europe in innovation.  (Turmock, D.;1989: 40)  It was reported that in many respects, the industry  in this region surpassed Germany.

A huge textile industry developed in Vienna.  In Prague, cotton printing became the dominant industry with the accompanied dyes industry.  Bohemia, in general, had well-developed textile manufacturing.  (Hiemstra-Kuperus, E. 2010)  This means that by the early 1900s, sodium nitrite was available in and around the city of Prague.

Prague and surrounding areas were not just a consumer of chemicals.  The scientific and industrial environment was sophisticated and advanced and they produced many of the chemicals for their industry themselves, primarily in support of the textile printing industry.  The point is that we when we deal with the people in Prague, we are talking about people who understood chemistry (my personal experience is that this is still the case to this day).

D. Hirsch, for example, established his factory in Prague to “provide acid for calico printing in 1835.”  F. X. Brosche supplied  printing inks, paint, and pharmaceuticals.  The first major chemicals producer in the area was Johann David (J. D.) Starck had a sulfuric acid plant near Zwittau (now Svitavy in the Czech Republic), 183km to the east of from Prague, in 1810.

Between 1810 and 1850, J. D. Starck expanded into a multi-plant operation manufacturing a variety of products including phosphates at Kaznau (now Kosnejov, in the Czech Republic), 109km South West of Prague.   He was big enough to own his own source of coal from the Falknov (Sokolov) basin.   (Turmock, D.;1989:  39)  It all supports a picture of sodium nitrite being readily available in Prague as part of the chemicals associated with the dying and textile printing industry. [9]  More than that, the Bohemian people proofed to be innovative and capable in matters pertaining to chemistry.

At the end of the 1800 and beginning of the 1900s, Prague was a fertile breeding ground for industrial and food innovations.  A case in point is the phenomenal success of Pilsner named after the city of Pilsen (Plzen).  The innovation was the application of steam power to the production of chilled lager.  It was an important improvement in the old processes and helped the town of Pilsen to become one of the great European beer producers. (Turmock, D.;1989: 40)

Another Bohemian innovation was the invention of the sugar beet refining process through diffusion to produce refined sugar.  “The diffusion process was discovered in Seelowitz  (Zidlochovice) in Moravia by J. Robert, the son of the founder of the first sugar beer factory in the Czech lands.”  Within a few years, 25 other factories converted to this process and sugar refining machines were being exported to Germany and France.  The Prague-based engineering firm of C. Danek (founded in 18540) was particularly successful.   (Turmock, D.;1989: 40)

The kingdom boasted the most sophisticated food industry with a very strong scientific backing from the local academia in Prague.  Under their leadership, the first food code in industrialized Europe was created, the Codex Alimentarius Austriacus, which is the basis for international food legislation to this day.   (The Life and Times of Ladislav NACHMÜLLNER – The Codex Alimentarius Austriacus) It also became the first country in the world to specifically allow the use of sodium nitrite in food, before Germany and the US.

Not just was Prague and the Bohemian people leading the world in food innovation and food science and chemistry, but the existence of large food industries created an environment where other food industries would benefit, for example, the meat industry.  (Turmock, D.;1989: 39, 40)

The Master Butcher from Prague

The ether around Prague and the Bohemian people was right for a company or an individual to step forward and take up the challenge to work out the details of how to use sodium nitrite directly in meat curing.


Into this advanced and scientifically and industrially mature environment, Ladislav Nachmullner was born on 2 April 1896. (Eva’s Beloved Dad) In 1912, the Bohemian boy, Ladic (Ladislav) NACHMÜLLNER was 16 years old. His dad tragically burned to death four years earlier, in 1908, when his clothes caught fire in his home. His mother had just passed away from tuberculosis and as the oldest child, the responsibility fell on him to care for his siblings.

Ladic got an opportunity to learn the art of meat curing to provide for his siblings in a land where chemistry was well understood, salts were of high quality, sodium nitrite was widely available and there was an appetite for and a culture of innovation in food production. The kingdom boasted the most sophisticated food industry with a very strong scientific backing from the local academia in Prague. Under their leadership, the first food code in industrialized Europe was created, the Codex Alimentarius Austriacus, which is the basis for international food legislation to this day. (The Life and Times of Ladislav NACHMÜLLNER – The Codex Alimentarius Austriacus) More importantly for my quest to understand bacon chemistry, it was the first country in the world to specifically allow the use of sodium nitrite in food, before Germany and the US. This set the stage for a remarkable development.

Ladic knew sodium nitrite well from his father who was a glassmaker. Even as a boy, he would have been exposed to it. His father encouraged him never to enter the glassmaking profession and he instead chose curing as a way to provide for his siblings. He was taught the art of curing by a well-known butcher, Josef Pazderky from Praha, almost 600km from Prague. He was an unusually gifted young man who learned fast and an illustrious career followed.[10] At the young age of 19, he invented Praganda, which would become the most successful curing brine of its day, containing sodium nitrite. This was the year 1915 when he also started writing his book on Praganda.

Ladic knew sodium nitrite well. The seemingly boring facts of the early experiments on curing and the confirmation through science that it was indeed nitrite responsible for curing and nit saltpeter was cutting edge technology of the time and the scientific findings were reported upon in many publications and newspapers of the time. Ladic must have been an unusually gifted and curious person and he read these reports with great attention, realising that he may have the answer to a much faster and more controlled way of accessing nitrite namely through the direct addition of sodium nitrite to the curing brine.

He wrote that he discovered the power of sodium nitrite through “modern-day professional and scientific investigation.” He probably actively sought an application of the work of Haldane. Ladic quotes the exact discovery that Haldane was credited for in 1901 that nitrite interacts with the meat’s “hemoglobin, which is changing to red nitro-oxy-haemoglobin.” This must have made a profound impression on him which explains why he never forgot it. If it was not him personally, it must have been his mentors in Prague who decided to start experimenting with sodium nitrite to develop a meat curing brine.

The “modern-day professional investigations” that he spoke off would have been the input of master butchers who were not primarily interested in a quicker process but in a better end product. Saltpeter is potassium nitrate. The butchers did not like it due to the slightly bitter taste of potassium. Butchers who used Ladic’s brine would later put signs in their shop windows that their meat is free of saltpeter.

Another point that Ladic specifically addressed in his nitrite-based brine is the use of as little nitrite as possible. This shows an advanced understanding of the chemistry or curing and an ability to apply this to his trade. The little nitrite would still cure the meat much faster than even the mild cured techniques as the Irish called it or the tank curing technology as the English referred to it.

His fame as curer spread and he received employment offers from more countries. He moved to Austria and then, Switzerland for the duration of the war. He received offers for management positions from all over Germany, France, England, Holland, Switzerland, Romania, Yugoslavia , Poland and as far afield as America and China.


He says that he invented Praganda in 1915 (when he was 19 years old) and at a time when the use of nitrites in food was not legal in Germany.

We know that it was not legal in Germany before August 1914 when Walther Rathenau who created the War Raw Materials Department (Kriegsrohstoffabteilung or KRA) restricted the use of saltpeter to military purposes only and the use of nitrites in food was allowed. Germany again banned its use sometime during the war. The concession on sodium nitrite’s use in food was reversed after an accident in Leipzig where sodium nitrite was mistaken for table salt and 34 people died. (Concerning Nitrate and Nitrite’s antimicrobial efficacy – chronology of scientific inquiry) This must then have happened sometime in 1915.

The impression one gets from reading his life story through the writings of his daughter Eva, is that he probably learned the basics of nitrite curing early on and this “paid his way” on many travels through Europe. Along the way, he must have continued to refine and perfect his formulations and solve the many challenges of using such a potentially dangerous chemical. (For a detailed analysis of the technical challenged facing him and how he dealt with it, see Ladislav NACHMÜLLNER vs The Griffith Laboratories.)

His move to Switzerland for the remainder of World War One is of interest. In Switzerland, the Polish chemist, Prof. Mościcki of the University of Freiburg, invented a process to use atmospheric nitrogen to produce both nitric and nitrous acid (US patent US1097870) in 1901 through the use of an electric arc in a closed container. (

In 1910, a factory opened in Switzerland, Chippis, in Wallis canton, where the world’s first nitrous acid was produced using Prof. Mościcki’s electric arc process. ( This means that a factory producing nitrite was in operation in the same country where Ladislav lived, during the war.

It is equally important that Prof. Mościcki opened another factory in Poland during the War, the Azot nitrogen factory near Jaworzno. ( Jaworzno is less than 460km from Prague.

From the evidence of his life, handed down to us by his daughter, Eva, he returned to Prague from Switzerland in 1929 and set up his first outlet where he sold Pragnada and ham moulds which he invented. It makes Prague the center of the development to add sodium nitrite directly to meat, other than canned meat.

The Salts from Prague

The history of Ladislav Nachmuller not only points to the first commercial curing brine containing nitrites but also to the use of pure salt from the regions surrounding Prague.  Using the correct salt was very important to Ladislav.  The area around Prague, like the neighbor to the north, Poland, was famous for the production of high-quality salt.  Ladislav procured salt from various mines, including from the salt producer, Solivary Prešov.  He gives the requirement for good salt as pure, clean, and “regular salt.”  This mine delivered on these requirements.

Mining at Solivary Prešov started as far back as the 13th century.  The salt was produced from “brines” (water saturated with a salt solution) where the water was evaporated.  First in pans and then in boiling rooms.  The final result was good quality NaCl (table salt) which has been popular among butchers in the area on account of its purity. (From private communication with the museum curator, Prof. Marek Duchoň)

Historical records inform us that the salt production exceeded local consumption, which points to the fact that the salt from Solivary Prešov was widely traded. The technology used in producing the salt was sophisticated. (

An interesting fact, relevant to our current discussion, is that the mine produced its own sodium nitrite since 1945.  It falls outside our time of interest and the production has since been discontinued, but the fact that producing sodium nitrite was fairly “widespread” and the technology, common in the area is fascinating.  (From private communication with the museum curator, Prof. Marek Duchoň)

prague saltSodium nitrite, produced at Solivary in 2007.

This is a key fact in piecing together why it was “natural” to call the sodium nitrite/ sodium chloride mix that Griffith imported into the USA, Salt from Prague.  The region was indeed famous for its salts.

A Fork in the Road

Ladislav’s invention was a fork in the road for nitrite technology. A new and “more direct” way of getting nitrite in the curing brine was developed. It is not surprising that it happened in the part of the world where nitrogen technology was best understood and where people were mesmerised through the opportunities created by the science of chemistry. It challenged the Irish mild cured system and the Danish and English Tank curing systems, as they called the mild cured process, by offering an even faster curing solution and one which is “safer”. The exact quantity of nitrites added can be much better controlled with this new system and when it comes to a substance such as nitrite that is poisonous in too high dosages, being able to control the amount of ingoing nitrite into the meat is very important.

Almost concurrent with Ladislav’s invention was events in Germany that brought about a wholesale conversion of German meat curers to this new and faster technology. Its getting time for Minette and my hike down to the promenade where we plan to do a 15km this afternoon. Caring for the body is just as important as caring for the mind.

I am glad you are getting out and seeing exhibitions in this great city where you find yourself! Learn as much as you can while you live in Amsterdam!

Lots of love from Cape Town,

Dad and Minette.

Further Reading

Difference between Fresh Cured and Cooked Cured Colour of Meat.

Mechanisms of meat curing – the important nitrogen compounds

Reaction Sequence: From nitrite (NO2-) to nitric oxide (NO) and the cooked cured colour.

The Naming of Prague Salt

Tank Curing Came from Ireland

The Mother Brine


(c) eben van tonder

Bacon & the art of living” in book form
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