Introduction to Bacon & the Art of Living

The story of bacon is set in the late 1800s and early 1900s when most of the crucial developments in bacon took place. The plotline occurs in the 2000s, with each character referring to a natural person and actual events. The theme is a kind of “steampunk” where modern mannerisms, speech, clothes, and practices are superimposed on a historical setting. Characters interact with one another with all the historical and cultural bias that goes with this. The period of technology it covers is breathtaking. Beginning in pre-history, it traces the development of curing technology until the present, where bacon curing is possible without adding nitrites.

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Henry Denny’s Singeing of Pork and Related Reflections on Vecht

20 April 1920

Dear Children,

My reflections on Aron Vecht have been good for me. I kept in contact with his grandson, Dr. Romeo Vecht, who continued providing me with gold nuggets on his grandfather. Dr. Vecht told me that the family were Dutch for centuries and were mainly agricultural people living in the north of Holland. Hy grandfather, Aron Vech, married Bernardine Coopman van den Begh. Zadok van den Bergh (1769–1857) was a religious Jew who invented margarine in Holland in the 1830s.

Zadok was a merchant and leader of the Brabant Jewish community, living in the small village of Geffen. “His son Daniel van den Bergh (1794–1866) headed a textile factory from 1836, which under the name Bergoss (1856–1986) made Oss into a centre of the textile industry. His younger brother Simon van den Bergh (1818–1907) continued their father’s business, bartering groceries and dry goods for butter supplied by peasants from the surrounding countryside.” (Encyclopedia.com)

“In 1872, Simon, helped by his sons Samuel, Arnold, Henry, Isaac and Jacob, started production of “artificial butter,” or Oleomargarine, in a factory in Oss, in 1890 replaced by a bigger one at Rotterdam.” (Encyclopedia.com) The company, known as Samuel van den Bergh & Co., was involved in the production of vegetable oils and fats, with a focus on margarine.

Simon had a sister, Catherina van den Bergh. She married a Coopman and had a daughter, Bernadine Coopman. Bernadine Married Aron Vecht in 1875. Vecht was sent to London to introduce margarine, a mix of tallow (rendered beef fat) and milk in England. And although they were both Dutch, they were married in Whitechapel. The farmers did not welcome the margarine in London, and the Vecht couple decided to do something else.

The Van den Bergh family did not give up on the London venture and eventually, “Henry and Jacob opened a branch in London, while in 1888, a margarine factory was opened in Cleve (Germany). A few years later, in 1895, a factory was opened in Brussels.” (Encyclopedia.com)

The link between Vecht and the Van den Berg family must never be forgotten since it was a Van den Bergh who, in all likelihood, helped to finance Vecht’s Inter-Marine Trading Co. The Van den Bergh’s margarine business “developed rapidly and became one of the leading margarine manufacturers in Europe. In 1930, the Van den Bergh Margarine Union Ltd. merged with Lever Bros. Ltd., forming Unilever Ltd., which expanded into a giant international concern. Simon’s son, Samuel van den Bergh (1864–1941), obtained a leading position in the firm.” (Encyclopedia.com)

Vecht’s curing system started with the finishing off of pigs. Curing was done using elements of Oake’s mild cured system and a secret preservative used in the process. It also had elements of the mechanisation of pork singeing.

Ireland – 1866: The Patent of Henry Denny

It was said that Vecht’s method involved the hermetically sealing of the pigs. In a Press article from 1893, Vecht describes his process as follows. “After the pigs are killed and dressed in the usual manner, the carcasses are allowed to cool. They are then placed in ovens and subjected for a certain time to heat. This partially roasts the outer surface and melts a portion of the fat beneath the skin. The carcasses are then plunged into cold water, and the melted fat becomes solid so that the pig is, so to speak, hermetically sealed within itself. The patent antiseptic fluid is then by pressure injected into the carcase, which becomes wholly impregnated, and the curing is complete. With the antiseptic flavour, according to taste, may be added.” (Press, 1893) Here, he marries his system with the singing system invented by Denny in Ireland.

Let’s first get some background on Denny. In the first half of the 1800s, Ireland was a fertile field for innovation. An excellent example is found in the person of Henry Denny. Part of his remarkable legacy is a firm that once was the largest bacon producer in Europe, Henry Denny & Sons. Henry was born in Waterford, Ireland, in 1790.

Denny started as a provisioner merchant in Waterford. The first reference to him as a bacon merchant comes from 1846. In 1854, he started using ice in bacon curing, which allowed him to cure meat all year round, like the Harris operation in Calne, who brought the concept to England and patented it. The bacon he cured was also referred to as mild cured bacon, and a patent was granted in 1857 on his process.

I failed to discover the exact nature of his patented process till Aron Vecht introduced me to it. Like the process invented by C & T Harris called Sweet Cured Bacon, Henry’s method used much less salt. The priority for developing the first mild cured system, however, goes to William Oake from Ulster, whom we know invented this around the time when Denny had his merchant business or shortly after this and well before Denny entered the pork processing trade. Denny undoubtedly achieved mild cured bacon in a way different from William Oake since he relied on refrigeration.

Henry’s curing system is described in one source I consulted (Geocaching), which seems to be a copy from another work that is unfortunately not referenced. All my attempts to locate the original publication have been in vain. The author describes it as follows: “Until the early 19th century, pork was cured by soaking large chunks of the meat in barrels of brine for weeks. Shelf life was poor, as often as the inside of the chunks did not cure properly, and meat rotted from the inside out. Henry Denny and his youngest son Edward Denny, introduced a number of new innovations – he used long flat pieces of meat instead of chunks; and they dispensed with brine in favour of a dry or ‘hard’ cure, sandwiching the meat in layers of dry salt. This produced well cured bacon with a good shelf life and revolutionised Ireland’s meat industry. Irish bacon and hams were soon exported to Britain, Paris, the Americas and India.“

Reference is made to the fact that Denny invented several curing techniques, and if the description given is correct, it would be one of several inventions. Taken at face value, I doubt the superiority of his system over Oake’s invention. It also comes so late in terms of dates that I doubt this could be the patent awarded in 1957. By this time, meat injection was already well established, which solved the shortcomings of William Oake’s invention in his mild cured system of simply filling the curing tanks with brine to diffuse into the meat “naturally.” If this were, in fact, the patent that was granted in 1857, it would represent a step backwards.

A significant contribution to my understanding of Denny’s system is that he acquired a meat curing company in Denmark in 1894. The reference is Lets-Look-Again, which also seems to quote an uncredited source. This purchase “introduced Irish meat curing techniques to Denmark.”

I have, over the years, come across several authors who made the same claim that the Irish meat curing system was introduced to Denmark in the late 1800s after an Irish firm acquired a Danish processing company. They never give the name of the Irish firm in question. However, the end of the 1800s was the wrong time for introducing William Oake’s system to Denmark. By this time, it was already well established in Denmark, and the likely transfer of the technology to C & T Harris took place from Denmark either at this time (closing years of the 1800s) or in the opening few years of the 1900s. For this reason, I never used the reference, but I was always curious about who the Irish firm was wrongly credited for the transfer of the original mild cure technology to Denmark. If, as I now suspect, the Irish firm referred to was that of Henry Denny, the question comes up as to exactly what the invention was that he took to Denmark!

Denny could very well have been the inventor of the pork rasher. Geocaching quotes an unnamed source: “the rasher (a piece of bacon to be cooked quickly or rashed) was reportedly invented in 1820 by Henry Denny, a Waterford butcher who patented several bacon curing techniques still used to this day.” It must be mentioned that Denny’s career only started in 1820, but that was not as a butcher. As a merchant, he entered the pork processing business only in 1854. There could still be credibility to the claim, which I base on the widespread nature of the story in Ireland. Maybe he was a young man with unusual interest and creativity in selling pork at his trading business. The claim is, however, doubtful.

This now brings us to the link between Aron Vecht and Henry Denny, which led me to discover the actual invention of Henry Denny and his mild curing process. One aspect of pork curing I overlooked for years was the importance of singeing. Singeing pork was nothing new. Removing the hair off the carcass and retaining the “rind” was done with straws for centuries. Тихомир Давчев beautifully illustrates the old method in their set of photos featured below.

Henry Denny automated this process. He re-looked at the process in light of the latest industrialised equipment available. One publication from 1866 describes it as follows. “Each pig is hoisted by the hind leg, it is hooked on to a lever, which suspends the animal head downwards, and its throat is slit with a sharp knife; the blood caught in a receiver flows into an external tank, from whence it is carted away. The leg is then fixed to a hook, which slides on a round iron bar placed overhead on an incline. A push of the hand sends the dead pig with railway speed to the singeing furnace, a distance of 30 to 50 feet. Here it is taken by a crane, placed on a tramway, and run into the furnace, where the flame impinges on it, and in a moment, all the hair is removed. The carcass is re-hooked by the leg and passes into another room, where it is disembowelled, the entrails being transferred to an underground region or dealt with. The head is next removed, and then the backbone is cut out, thus dividing the carcass into two flitches, which pass, suspended on the round bars and without handling, into the cooling room, where it hangs until the meat is firm.” (Fraser’s Magazine for Town and Country, Vol. LXXIV July to December 1866) 

His fame was in the first place due to his invention of the automated process of pork singeing. He may have also called his method “mild cured,” as with the aid of refrigeration, he would have obtained the same result as did William Oake, who invented the original mild cured process.

It is what I suspect Aron Vecht did (also called his method mild curing) and his claim that the critical feature of his process is his secret antiseptic brine formulation. It was unnecessary to secure bacon’s cooked/ cured look, making using an antiseptic plausible without the need for actual technical curing as we understand it today. The absolute brilliance of Vecht was this antiseptic, as well as his adjustment of cold storage temperatures from chilled to below freezing.

Nothing would have distinguished his pork from the Oake system, which relied on sal prunella to achieve “mild cured” meat. (William Oakes Mild-Cured Bacon and Mild-Cured Bacon and the Curers of Wiltshire) It illustrates the inherent problem in using the result of the process (i.e. milder bacon) as the name of your product. If the result is the same, but a different method was used to arrive at it, how would the consumer know (or care)? From a trademark perspective, it makes it tricky since the actual phrase is difficult to protect as it would be the general way people would refer to the bacon, not heavily salted. It is like trying to trademark the phrase “well cooked.”

The one point, which, as it stands right now, I believe, is that Denny invented the automated process of singeing the carcass. The publication I cited above is the earliest mention of automating the process I could find, and I am convinced that Vecht got his method from Denny and Oake. The alternative antiseptic was, in all likelihood, his addition.

Auto Curing requires pressure cylinders (autoclaves or retorts), making the auto-cure bacon’s production even more expensive than mild cured bacon. It is the only patentable process because neither sweet cure nor mild cure nor Vecht’s procedure nor Denny’s singeing process is so unique that someone with mediocre technical skills cannot copy it, and it is not patentable. The existence of Aron Vecht and his process proves this. It relied on how the animals were finished, the general system of Oake and Vecht’s patented antiseptic and his trademarks, which he linked to his method, as we looked at in the previous letter.

In this regard, it is similar to the refrigeration patent that Harris took out – may I add. Anybody could, and I am sure did, make small changes to the system to show it to be unique and to overcome the trademark restrictions. This was not the case with Auto Cure, which relied on special equipment. To this day, people buy bacon, and the exact process is, as it were, lost in the final product. Trade marks speak to consistent quality, but in the final analysis, bacon has always been and still is today a commodity that most people buy on price (given a relatively wide range of acceptable product quality). Exactly how it is cured is irrelevant.

I have personally been faced with this exact issue over the years. One invents a new process, but the protection of the process only lasts as long as your staff remains with you. The moment they move away, the process is gone! To this day, meat plants are notoriously shrouded in secrecy. From British producers to the largest bacon producer in South Africa (close and good friends), they refuse me access to any of their plants because they are scared I will see something I am not supposed to. Phil Armour was famous for trying to break the secrecy that existed even amongst his plant managers. 

I wonder if this does not also explain why Vecht did this, not in Holland or the USA or England, but in faraway New Zealand! Processors all claim that they invented processes! Whichever process one talks about!

See the article below, Effect of Singeing on the Texture and Histological Appearance of Pig Skin. (6) It beautifully describes the process, and it ascribes the tradition to be Danish. The reason I will still give priority to the invention of Denny is that Denny created bacon-curing plants in Denmark. I believe that the technology was invented by Denny, transferred to Denmark, where it was used on a large scale and subsequently made its way to the Harris operation in Calne and other Wiltshire curers (including Oake Woods – son of William Oake, who invented Mild Curing).

There are many traditions that mild curing, for example, was invented by the Danes, but after twenty years of research, I know this is incorrect. As I already discussed, I can imagine that Denny also arrived at a “milder cured bacon” through his process, but he was by no means the first to have done so. The invention is Irish and was kept a secret till disgruntled Irish curers (on strike) were lured to Denmark under a Danish continual learning scheme where they were paid handsomely to train the Danes in Mild Curing.

1911 Description of What Denny and Vecht’s Process Looked Like

There is a rare description from the Journal of the Royal Society of the Arts, 1911, describing mild cured bacon production without curing baths or old brine. It has all the elements of the Denny/ Vecht system. I made the point that Vecht did not always use the complete procedure in New Zealand, especially when he demonstrated its effectiveness to farmers. The 1911 process description exemplifies such an “abbreviated” method.

It, interestingly, says that it was not too long ago when curing methods were closely guarded secrets, handed down from one generation to the next orally. By 1911, this was no longer the case, and the following account is in this new tradition.

The animal is stunned and bled, after which the carcass is placed in a tank with 70 – 85^o C (160 to 185 deg F) water, where the carcass is scalded and the hair removed. The carcass is then pushed into the singeing furnace. It specifies that where Wiltshire bacon is produced, singeing is always used.

The carcass is left in the furnace for 25 seconds. The soft subcutaneous fat is changed to hard fat after the carcass has been removed and is cooled down in a cold water bath.

The carcass is hung on dressing bars where it’s cleaned and disembowelled. Singed and unsinged carcasses are, from this point onwards, treated in the same way. They are cleaned with cold water and scraped clean. The intestinal offal is removed and handled separately. Kidney fat is still in the carcass at this point.

The carcass is now split, and the backbone or vertebral column is removed. Secondary offal is removed being the head, feet and kidney fat. It is the removal of the vertebral column which liberates the two sides. The sides were then hung until sufficiently cooled down to around 38^o F or 3^o C.

“When the temperature is riched, transfer the carcass to the curing cellar. Here the blade bone is drawn out.” According to their method, curing did not involve reusing the old brine. Instead, a fresh pickle is pumped into each side at a pressure of 40 lbs. to the square inch. “The pickle is pumped through a pickle needle with a number of perforations arranged in a spiral manner through which the pickle is discharged. The sides are now laid one by one on the floor of the curing cellar, which is maintained at a temperature of 42^o F or 5^o C. The atmosphere must be humid and moist. Each side is covered over by an equal mixture of salt, saltpetre and curing preservative, on top of which is placed a heavy layer of salt.” (Journal of the Royal Society, 1911) No mention is made of a liquid pickle.

“Under these conditions, the curing proceeds and the salt, as it melts, take the place of the meat juices.” (Journal of the Royal Society, 1911) In their view, the salt and the rest of the cure “replaced” the meat juices, which were drawn out. They found that less salt can be used under refrigerated conditions—the process lasts 14 days. A statement is made that the bacon can then be sold as “mild cured bacon”. Alternatively, the bacon could be washed, dried, smoked and sold as smoked bacon.

An interesting comment is made that the bacon would not keep very long in the mild-cured condition. For the bacon to last long, it had to be kept in the salt. Farm-cured bacon is typically kept in the salt for 28 days.

A fascinating and insightful section follows, discussing the curing process in detail. “The exact process which goes on in the production of bacon is not merely the displacement of the meat juices by a solution of salt and curing material. There is also the presence of micro-organisms, which are always to be found where flesh of any kind exists. These putrefactive organisms assist in the curing process by breaking down some of the tissue of the meat, notwithstanding the presence of salt, which has no antiseptic effect on some of them. This is how the bacon flavour arises as distinguished from fresh or pickled pork. The flavour is largely due to decomposition.” (Journal of the Royal Society, 1911) That scientific thought has been progressed by this time is clear. The use of the word micro-organisms is instructive. Still, surprisingly, they were at this point in Britain utterly ignorant of the work in Germany related to the chemical reactions as the basis for curing – at least the bacon curing community was.

What we have here is clearly the Denny/ Vecht curing system, not tank curing, which was invented by William Oake and later became part of the Wiltshire brine system. Another observation is in order related to the use of the Wiltshire cut in New Zealand. To this day, the largest bacon producer in New Zealand, Hellers, uses the Wiltshire cut in its deboning hall. In all probability, this was introduced by Vecht and was part of his curing system, as described in the Journal of 1911. This is far more than a description of the integration of Denny and Oake’s systems.

One can see the elements of the complete Wiltshire system emerging through the progress in understanding the role of microorganisms as essential in dry-curing. For a comprehensive discussion on this and the function of “decomposing” microorganisms in salt diffusion during dry curing, see Evaluation of Dry Curing with Saltpeter (with and without sugar). It would have been very soon after this when they became aware of the work of Ponenski, Notwang, Lehmann, KIßKALT, and from the United Kingdom, the landmark work of Handane, who all published before 1910 and elucidated the chemical reactions in curing. (The Fathers of Meat Curing) In terms of microbiology, the work of Meusel, who published as early as 1875 and identified the reduction of nitrate to nitrite in wastewaters by bacterial action and Gayon and Dupetitt, who elaborated on his work and coined the term denitrifying bacteria (1882) would have been syphering through the channels of science into Bristol on the river Avon, servicing Wiltshire. Liebig mentored the last two researchers, and their work would soon lead to the full Wiltshire system. (The Polenski letter)

The system left out sal prunella. There is mention that Vecht used a dry cure version of his system, and the description given above may very well be that exact system.

Aron Vecht continues to inspire me from beyond the grave. How he thought and the energy with which he lived challenges and inspires me. It is my greatest joy to share this with you. While you were growing up, I travelled the world uncovering the secrets of bacon curing. Today, it is you who moved abroad and travel the globe, having adventures of your own and I am left in Cape Town to reflect on the many experiences and adventures of my life. Enjoy every moment of your adventures!

Lots of love from Cape Town,

Your Dad

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(c) eben van tonder

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Notes

Note 1: Liquidation Sale Notice

The notice of the liquidation reads as follows:

MESSRS. STEWART and MORTON, at NOWRA, on account of THOMAS MARRIOTT, Esq., Liquidator of the Shoalhaven Co-operative Bacon Curing Company, Limited in Liquidation).

BACON CURING FACTORY at Bomaderry, N.S.W., and other Assets of the above Company, consisting of the following:

1. 4 acs 1 road 18 perches, being lots 9 and 10 of Section 33, on Deposited Plan No. 2880, in the Town of Bomaderry, Parish of Bunberra,county of Camden, TORRENS TITLE million to reservations in Crown Grant), withFactory premises and fixed plant and machinerythereon, as per schedule No. 1
2. Movable Plant, Office Furniture, Horses, Wag-gone, Carts, and Harness, as per Schedule No. 2.
3. License to use exclusively in NSW. process for curing Bacon known as “Vecht Mild Cure Process.”
4. “York Castle” Trade Mark for Bacon.

Items 1 and 3 are under mortgage, on which there is a Band of £2050, with Interest at a 5 per cent, per annum, from 2nd June 1900, owing, and will be sold subject thereto.

Item 3 Is held under certain Deeds and Documents, which, together with the Mortgagee over Items 1 and 3, may be inspected at the Offices of Messrs. Perkins. Stevenson, and Co., of 122 Pitt-street, Sydney, Solicitors.

Any Assignment of Item 3 is subject to consent of ARON VECHT, WILLIAM STOKES, and the CHRIST CHURCH CHURCH MEAT COMPANY, Limited. Lists of the Plant, etc may be inspected, at the Office of THOMAS MARIOTT, Esq. and the Auctioneers, at Nowra, and at the Offices of Messrs. PERKINS, STEVENSON, and CO., Solicitors, Sydney.

By order. THOMAS MARRIOTT, Liquidator, ‘

The Sydney Morning Herald (NSW, Tue 29 Jun 1909)

Note 2: York Castle Bacon

The York Castle Trademark is of huge interest. William Stokvis of Brussels instituted legal action against Barnes Bacon Company Ltd. (Mr WJ Gale being the managing director at this time). The lawsuit related to the use of a secret curing formulation for bacon and hams in 1936. The plaintiff alleged the unlawful use of the trademark and he claimed that this secret method was alleged to be used for bacon made under this trade name when in reality, so he alleged, it was not always used.

The judge said in the judgement that York Castel bacon has been sold for years throughout New South Wales and that the secret mild cured formulation was attached to it. An agreement was entered on 20 March 1922 in which Stokvis gave Barnes Bacon Company Ltd. the right to use the secret curing formulation and the trademark for 10 years in exchange for monetary compensation for every pig so cured in New South Wales. In addition, Stokvis agreed in June 1922 to pay James Macgregor (an expert in mixing the cure and supervising the curing) half of the royalties received from Australia and New Zealand. Two tradenames were involved in the agreement being “York Castle” and “More Pork.”

In June 1922, JM Watt became the owner of the trademark limited to New South Wales and in January 1926, its scope was extended internationally. Watt dies in 1926 and the partnership created in 1928 ceased in 1928. In 1929 Stokvis became the owner of the trademark. He subsequently renewed the trademark till 1949.

It was established that pork was cured for a period by Barnes Bacon Company Ltd using a curing method, different from the secret mild curing method, yet, the secret curing method was attached to the trade names. Key witnesses were Messrs. WJ Gale, A Robertson, WJ Read, and Colin C Gale. The judge regarded the witness of all except Colin C Gale as unreliable.

So far it’s all of little interest or direct bearing of our historical consideration of various curing methods. One of the legal counsels referred to a previous case between Orange Crush (Australia) and Cartell (41 C.L.R. 282) where the high court found, by majority decision, that the pickle had lost its identity in the final product. The judge did not accept the point as being applicable in this case, but it is of supreme importance for our current consideration.

It has been my contention for many years that unless a specific piece of equipment, fully protected under patent laws is attached to a certain curing or other processes; or, unless a trademark is linked to a process and the agreement between the licensor and the licensee specifically links the method of curing and the trademark, if the outcome is equal, any process loses its identity in the final product and a process or formulation without a trademark so linked to it or the use of patent-protected equipment, curing methods or any meat processing methods are essentially unprotectable.

It is interesting that the judge accepted the argument of WJ Gale that “a different cure is only a matter of the first pickle that is put into bacon.” Judgement was in favour of the plaintiff.

The Sydney Morning Herald (Sydney, New South Wales, Australia) · 16 Jun 1936, Tue · Page 6

Note 3: From The Waikato Argus, Friday, November 22, 1901.

The issue of temperatures takes a front and central role in the saga. The following newspaper article deals with this.

“Frozen pigs are arriving in England from New Zealand, to be ‘borne cured’ for the British breakfast table (say the Daily Mail). This explanation is that the world is short of pigs, and as people still insist on eating pork the shippers and curers are straining every nerve to reach the remotest parts where the pig is sold. This is why England is buying bacon from Siberia, Russia, Denmark, Holland, Canada, the United States, Australia, and a score more of our colonial friends and foreign rivals. Hitherto this foreign bacon has always arrived in England already cured, and since it is ‘mildly cured ’ to suit the British palate, a very large portion of the bacon sold to the householder is slightly tainted. To prevent this numerous attempts have been made to put the dead pig into ice and turn him into bacon on arrival in England. But the lowering of the temperature below 32deg Fahrenheit (0 deg C) has ‘invariably faded the flash into a pale, unpleasant colour and alienated the affections of the British matron. Now, however, by what may be called a triumph of transit and cure, a most promising and important trade has begun between New Zealand and England. By employing the Vecht curing process, a New Zealand firm is shipping pigs from that distant colony, placing them in refrigerators with a temperature of 20 deg Fahrenheit (-6 deg C), and curing them here on the banks of the Thames with apparently perfect success. This success is obtained by first treating the carcase*, before they leave New Zealand, by the Vecht curing process, which allays the action of the cold, and so sterilises the flesh as to prevent the changes which has hitherto interfered with the successful curing at Home of what is grown abroad. Messrs Trengrouse and Co., who are colonial shippers on a huge scale and the British agents of Armours, of Chicago, are encouraging this new process, and prophesy for it a vast influence on the bacon trade.”

Note 4: Interview with Aron Vecht

Note 5: The Grandfather of Henry Trengouse: Foundation of Principle

Note 6: Effect of Singeing on the Texture and Histological Appearance of Pig Skin

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References

Dr James Anderson (personal correspondence between him and Eben)

 

The Advertiser (Adelaide, SA : 1889 – 1931) ,Thu 24 Dec 1908

De Beer, G., Paterson, A., and Olivier, H.. 2003. 160 Years of export. The History of the Perishable Products Export Control Board.

The Bush Advocate. Thursday, May 11. New Outlet for Farmers, Volume IX, Issue 777, 11 May 1893, Page 2

Dommisse, E.. 2011. Sir David Pieter de Villiers Graaff: Sakeman en Politikus aan die Kaap 1859 –1931.

https://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/bergh-van-den

Fraser’s Magazine for Town and Country, Vol. LXXIV July to December 1866

Ice & Refrigeration, Vol 20, Jan – June, 1901

The Jewish Voice, St. Louis, Missouri, Friday, December 04, 1908

Jewish Herald (Vic. : 1879 – 1920),  Fri 22 Jan 1909

Journal of the Royal Society of the Arts, no 3078, Vol LX, 17 November 1911

Lebrecht, N. 2019. Genius & Anxiety: How Jews Changed the World, 1847-1947. Simon and Schuster

Molander, E.. 1985. Effect of Singeing on the Texture and Histological Appearance of Pig Skin. Royal Veterinary and Agricultural University, Department of Meat Technology and Process Engineering, 11 Howitzvej, DK-2000 Copenhagen F, Denmark

1894, New Zealand, Patents, Designs and Trade-Marks

The Standard, London, Greater London, England, Saturday, November 16, 1889

The Sydney Morning Herald (Sydney, New South Wales, Australia)16 Jun 1936, Tue

The Waikato Argus, Friday, November 22, 1901