5. Concerning Ladislav NACHMÜLLNER and the invention of the blend that became known as Prague Salt.

by Eben van Tonder
27 June 2015

Available in PDF:  CONCERNING LADISLAV NACHMÜLLNER AND THE INVENTION OF THE BLEND THAT BECAME KNOWN AS PRAGUE SALT

Also, see Bacon & the Art of Living, Chapter 11.03: The Direct Addition of Nitrites to Curing Brines – the Master Butcher from Prague

Prague 2

Introduction

Pork is turned into bacon by the reaction of nitrite. The story of nitrite and its use as curing agent is intriguing and an important part played off in Prague.  The story has never before been told in the West or in English.  This article is the first in a series of articles to follow on the life and achievements of Ladislav NACHMÜLLNER.  Here we intend setting the background information of events that led up to the invention of a nitrite curing brine in Prague.  It chronicles some of the events that lead to the story being told and the key people involved in bringing the story to the world.  It is also a human saga since it is told at a very emotional time as the daughter of the man responsible for the invention, having just celebrated her 90th birthday, enters the final days of her life.

Early history of salt to nitrite

At first only salt was added to preserve meat.  It was found that saltpeter had the effect of giving the salted meat a reddish colour and imparting a specific taste. It became known as curing.  The knowledge of saltpeter’s ability to cure meat has been understood in many cultures in various parts of the world for millennia, but  the widespread “change from vegetable dyes to saltpetre for the coloring or color preservation, respectively, of meat occurred between 1600 and 1750, probably near 1700. The addition of sugar which favours the reduction of nitrate to the active agent nitrite became common practice during the 19th century.” (Lauer K. 1991.)

Saltpeter is potassium or sodium nitrate.  Between the mid to late 1800’s, scientists started to work out that the nitrate was not the real curing agent, but its cousin, the far more toxic compound, nitrite.   A private laboratory in Germany, founded in 1848 by C.R. Fresenius recorded, for example, experimented with sodium nitrite as curing agent.  (Concerning Chemical Synthesis and Food Additives)   It was around the 1880’s that scientists discovered bacteria’s role in reducing nitrate to nitrite.  (Lauren learns the nitrogen cycle)

In 1891, Dr Ed Polenske, working for the Imperial Health Office, concluded that nitrite found in cured meats and curing pickle arose from bacterial reduction of nitrate. In 1899 two other German scientists, Kisskalt and Lehmann, confirmed that the reddish/ pinkish cured meat colour is due to nitrite and not nitrate.  (Concerning the direct addition of nitrite to curing brine)

The result of the work done in Germany is that by 1910 the reduction of nitrate to nitrite by bacteria and the priority of nitrite in curing was well understood.  The questions were now how nitrite would be obtained and added directly to the curing brines in order to reduce curing time and to control the amount of nitrite that ended up in the cure and how the process of turning nitrate to nitrite could be sped up.  On account of its toxicity, this was not and easy question to solve and two distinct methods developed.  One in Denmark and one in Germany.

Old Prague
Old Prague

The Danish invention

The Danes applied their knowledge of bacterial reduction of nitrate to nitrite and developed a curing method where they re-used brine that was “reduced” to nitrite already. They allowed fresh brine to be continually introduced into the system, bacterial reduction to take place and thus supplemented the nitrite concentration of the previously used brine.  This had the additional benefit of “seeding” new brine with just the right bacteria required for nitrite reduction.

According to this method they first injected fresh brine consisting of salt and saltpeter (potassium nitrate) into meat.  They then left the meat for several days in a cover brine. The cover brine was never changed and came to be known as the “mother brine.”  It was their source of nitrite that was directly applied to the curing process.  The mother brine was strained and boiled before it was re-used to eliminate pathogenic bacteria. (The mother brine)

Clues to the date of the Danish invention come to us from newspaper reports about the only independent farmer-owned Pig Factory in Britain of that time, the St. Edmunds Bacon Factory Ltd. in Elmswell.  The factory was set up in 1911. According to the newspaper reports they learned and practiced what at first was known as the Danish method of curing bacon and later became known as tank-curing or Wiltshire cure.  A person was sent from the UK to Denmark in 1910 to learn the new Danish Method.  (elmswell-history.org.uk) This Danish method involved the Danish cooperative method of pork production founded by Peter Bojsen on 14 July 1887 in Horsens (The mother brine).  The newspaper reports talked about a “new Danish” method.  The “new” aspect in 1910 and 1911 was undoubtedly the tank curing method.

Another account from England puts the Danish invention of tank curing early in the 1900’s.  C. & T. Harris from Wiltshire, UK, switched from dry curing to the Danish method during this time. In a private communication between myself and the curator of the Calne Heritage Centre, Susan Boddington, about John Bromham who started working in the Harris factory in 1920 and became assistant to the chief engineer, she writes: “John Bromham wrote his account around 1986, but as he started in the factory in 1920 his memory went back to a time not long after Harris had switched over to this wet cure.”

So, early in the 1900’s, probably sometime between 1899 and 1910, the Danes invented and practiced tank-curing which was brought to England around 1911.

It only stands to reason that the power of “old brine” must have been known from early after wet curing and needle injection of brine into meat was invented around the 1850’s  (The history of curing) even before the bacterial mechanism behind the reduction was understood.  Possibly even from before this time as the meat juices coming out during dry cure must have had the same extraordinary curing power.  It was however the Danes who took this practical knowledge, undoubtedly combined it with the scientific knowledge of the time and created the commercial process of tank-curing which later became known as Wiltshire cure.

Prague Bridges
Prague Bridges

The German invention

Where Denmark focused on harnessing the power of old brine, in Germany they were toying with the idea of using sodium nitrite as their source of nitrite.  Sodium Nitrite was by this time used extensively in an intermediary step in the lucrative coal tar dye industry that flourished in Germany and in the Austrian-Hungarian empire, notably around the city of Prague.  There was a second use of sodium nitrite in medicine. It was expensive to produce and viewed with some skepticism by the general public for use in food on account of its high toxicity.  (Concerning the direct addition of nitrite to curing brine)

It was the First World War that provided the transition events that caused the sodium nitrite to end up being used as the source of nitrite in curing brines.  Saltpeter was reserved for the war effort being one of the main components used in manufacturing of gunpowder and was consequently no longer available as curing agent for meat during World War One. (Concerning the direct addition of nitrite to curing brine)

In August 1914, the War Raw Materials Department (Kriegsrohstoffabteilung or KRA) was set up under the leadership of Walther Rathenau.  It was Rathenau who was directly responsible for the prohibition on the use of salpeter.  He therefore is the person in large part responsible creating the motivation for the meat industry in Germany to change from saltpeter to sodium nitrite as curing medium of choice for the German meat industry during Wold War One.  (Concerning the direct addition of nitrite to curing brine)

By 1917 nitrite was not only used for curing meat in Germany, but proprietary meat cures containing nitrites were being marketed across Europe.  (Concerning Chemical Synthesis and Food Additives)

Prague 1910
Prague 1910

Developments in the United States

Both these methods were being looked at very closely in the United States around this time.

The first recorded direct use of sodium nitrite as a curing agent in the USA was in a secret experiment in 1905.  The USDA approved its use as a food additive in 1906.  (Concerning the direct addition of nitrite to curing brine)

In 1915, George F. Doran of Omaha, Nebraska, filed a patent for using “sterilized waste pickling liquor which he discovered contains soluble nitrites produced by conversion of the potassium nitrate, sodium nitrate, or other nitrate of the pickling liquor when fresh, into nitrites.  As such his patent involved taking waste pickling liquor from the cured meats.”  This is the same concept as tank curing invented in Denmark some time before 1910 and probably after 1899. He states the objective of his invention as “to produce in a convenient and more rapid manner a complete cure of packing house meats; to increase the efficiency of the meat-curing art; to produce a milder cure; and to produce a better product from a physiological standpoint.” (US 1259376 A)

Despite the obvious advantage of a far quicker curing time of the use of sodium nitrite had over the tank cured Danish method, the fact that Doran still took the trouble to register the patent for a tank curing method in 1915 makes sense if one considers that tank-curing or the Wiltshire curing process became widespread in application in England.  Since it was early days for both methods, it was not clear yet which method would dominate.

By 1925 it was clear that sodium nitrite dominated in the United States.  A document  was prepared by the Chicago based organisation, The Institute of American Meat Packers and published in December of this year.  The Institute  started as an alignment of the meat packing companies set up by Phil Armour, Gustavus Swift, Nelson Morris, Michael Cudahy, Jacob Dold and others with the University of Chicago.  (Concerning the direct addition of nitrite to curing brine)

A newspaper article about the Institute sets its goal, apart from educating meat industry professionals and new recruits, “to find out how to reduce steers to beef and hogs to pork in the quickest, most economical and the most serviceable manner.”   (The Indiana Gazette.  28 March 1924).  In this statement is the clue to the reason of its dominance in the United States where bigger, better and faster was the call to arms for the new worlds industries.

The document is entitled, “Use of Sodium Nitrite in Curing Meats“, and it it is clear that the direct use of nitrites in curing brines has been practiced from earlier than 1925. (Industrial and Engineering Chemistry, December 1925: 1243)

The article begins “The authorization of the use of sodium nitrite in curing meat by the Bureau of Animal Industry on October 19, 1925, through Amendment 4 to B. A. I. Order 211 (revised), gives increased interest to past and current work on the subject.”  Sodium Nitrite curing brines would therefore have arrived in the USA, well before 1925.

The rest of the opening paragraph continues to elaborate on the reason for its preference.   “It is now generally accepted that the salpteter added in curing meat must first be reduced to nitrite, probably by bacteria, before becoming available as an agent in producing the desirable red color in the cured product.  This reduction is the first step in the ultimate formation of nitrosohemoglobin, the color principle.  The change of nitrate to nitrite is by no means complete and varies within considerable limits under operating conditions.  Accordingly, the elimination of this step by the direct addition of smaller amounts of nitrite means the use of less agent and a more exact control.”

Back in England, the longer curing time and the general method of producing bacon using the Wiltshire or tank cure method is still considered as superior in taste and quality to the quick curing method with sodium nitrite.  The fact that this is still practiced by reputable companies in England indicates that there are validity to these claims.

Prague
Prague

The Griffith Laboratories, Inc.

One of the American companies that introduced sodium nitrite to the world of curing is the Chicago based company of Enoch Luther Griffith and his son, Carroll Griffith.  They started to import a mixture of sodium nitrite and salt as a curing substitute for saltpeter from Germany in 1925.  The product was called Prague Salt (Prague Powder, 1963: 3)

Nitrite is very toxic to humans.  The lethal dose is between 2 and 6g for an individual.  Improper use of nitrite in curing operations has in the past lead to fatalities and the only way to overcome this is to mix it with table salt to “dilute” it.  (Lück, E. and Jage, M.; 1980: 90)  A problem in the early days was that if sodium nitrite and sodium chloride are mixed, the nitrite tends to settle at the bottom of the bag.

The Griffith Laboratories played a key role in overcoming this problem and in marketing the new curing brine in the USA.    They took the concept of the Prague Salt (sodium nitrite, mixed with sodium chloride) and in 1934 announced an improved curing brine, based on the simple use of sodium nitrite, where they fuse nitrite salt and sodium chloride in a particular ratio.  They called it Prague Powder.  (Prague Powder, 1963: 3, 4)  Their South African agents, Crown Mills brought the innovation to South Africa.

The benefits of Prague Salt and later Prague Powder over Saltpeter is dramatic.  Prague Salt (sodium nitrite, mixed with sodium chloride) does not have the slightly bitter taste of saltpeter (Brown, 1946:  223).  It allows for greater product consistency since the same percentage of nitrate was not always present in the saltpeter and the reduction of nitrate to nitrite takes longer or shorter under various conditions (Industrial and Engineering Chemistry, December 1925: 1243).  The big benefit was however in the curing time required.  Instead of weeks or even months that is required with saltpeter, curing could now be done in days or even hours with sodium nitrite.  (The Food Packer, 1954:  64)  From there, brand names like Quick Cure or Instacure.

The search for the origins of Prague Powder

In our own bacon curing company in Cape Town, Woody’s Consumer Brands (Pty) Ltd., we use Prague Powder to cure our bacon.  We buy this from Crown National, the old Crown Mills that was bought by Bidvest.  After a year of research I finally understood how and when saltpeter became the primary curing agent for bacon.  The cultural and scientific context was unlocked of scientists who started to understand, towards the end of the 1800’s, that it was nitrite and not nitrate who took priority in curing.  The Danish development that became tank curing in England and the flirtations in Germany with sodium nitrite before the outbreak of the Great War in 1914, are two direct consequence of these scientific discoveries in Germany.

A key aspect of the history of nitrite continued to elude me.  I have been wondering for years how the name Prague Powder came about.  I have spent many fruitless hours, over a few years, reading through countless documents on the internet and books on curing from around the world.  Who sold it to Griffith and is it possible that it was in Prague that sodium nitrite was first mixed with sodium chloride to make it possible to handle this very toxic substance.  This development was essential for the invention to work and a key to its universal acceptance.  I wondered if it is possible to find the name of the person or company responsible for this invention.

I contacted The Griffith Laboratories for more information.  They have been wonderful in sending me much information, but it seems as if this particular information is lost to them also.

The only facts that I knew for certain was that the invention of Prague Salt or at least its chemical composition and blend happened sometime between 1914, the beginning of the Great War, and 1925 when Griffith imported it from Germany.

I must have given up on finding the answer hundreds of times every month.  In frustration I would tell my children that I will never return to the search.  My son would joke with me and ask me when we were relaxing at home if I have broken my commitment and looked for clues again.

At the end of 2014 I wrote several mails to scholars, authors on meat history and meat industry professionals around the world who could possibly provide me with clues about the origin of the blend of salt and sodium nitrite in Prague.  Many of them returned my mail with further lists of researchers, institutes, universities, scholars and authors to contact, but in the end all were in vain.  All, except one.

By December 2014 I have given up on finding articles from Prague about the history of nitrite.  I decided to start working through the website articles of industry associations.  I began with the Czech Association of Meat Processors.  Just before Christmas 2014 I came across an article by Jan Katina, “Nitrites and meat products,” June 10, 2009.  The article contained two important clues.  The one was important in filling out the timeline for the use of sodium nitrite in the USA by making mention of a secret test that was conducted in America in 1905 and the second one mentioned a butcher by the name of Ladislav NACHMÜLLNER as one of the pioneers of marketing a revolutionary curing salt called Praganda.

LN

When I got home from work on 24 December 2014, after we completed our last shift before our factory closed for the Christmas break, I mailed Jan to get more information on Ladislav NACHMÜLLNER and his Praganda mix.  When I did not get a reply, I contacted the K+S Group, the current owners of the Praganda brand.  “K+S AG (formerly Kali und Salz GmbH ) is a German-based agricultural chemical and salt company, headquartered in Kassel. The company is Europe’s largest supplier of potash for use in fertilizer and, after the acquisition of Morton Salt, the world’s largest salt producer.” (A+G, Wikipedia)

In private communication between myself and the company, they confirmed that Praganda was a nitrite pickling salt and that it indeed originated in the Czech region.  The recipes and name are protected by trade marks and patents.

They confirmed that there is a difference in the current formulation between the basic standard nitrite pickling salt and their nitrite pickling salt, Praganda.  Praganda contains not only salt and sodium nitrite (the object of my investigation) but also sugars (white sugar, dextrose and dry starch syrup).  Sugars improve the effects of the nitrite pickling salts.

This encouraged me.  For the first time there was a glimmer of hope that I am on the right track.  Not only are we in the right region of the world namely around Prague, but we have confirmation of a nitrite pickling salt that originated in that region.

On 26 February 2015, Jan Katina wrote back to me.  He introduced me to Prof. Ing. Petr Pipek, PhD. from the University of Chemistry and Technology, Prague, Faculty of Food and biochemical Technology.  Prof Pipek turned out to be instrumental in unlocking the full story behind the invention of Ladislav NACHMÜLLNER and his Praganda mix.

He bought the book written on the life of Ladislav NACHMÜLLNER by his daughter from the publisher who is one of his former student and mailed it to me.  Through his students he discovered that Mr. NACHMÜLLNER’s daughter was still alive and living in Prague and undertook to locate her so that we could visit her.

Prof Pipek
Prof. Pipek holding the book.

After months of postal delays, the book on Mr. NACHMÜLLNER finally arrived in South Africa.  It is written in the old Czech language and no on-line translation software was able to do a translation on the work.  On 20 June 2015, after Tristan’s high school ruby match, I drove to the Gardens Shopping Center in Cape Town, where I met Monica and her husband, Mike, who are from the Czech republic and who run among other, a translation service in Cape Town.

There, in a coffee shop, I told them the story of nitrite, what I discovered and why I was so interested in the story of the master butcher Ladislav NACHMÜLLNER from Prague and his invention of Praganda.  Right there they read and translated large portions of the work.

monica
Monica who is translating the book with her husband, Mike.

We spoke about producing meat according to original Czech recipes right here in Cape Town in the Woodys factory; about the love of the Czech people for cured meats and about the magnificent delicatessen products we can make from that region.

From reading right there in the coffee shop, they confirmed that Ladislav NACHMÜLLNER was indeed one of the pioneers who was famous for marketing a mix of sodium nitrite and salt and producer of a manageable and highly effective curing mix by 1915, one year after the outbreak of World War One.  That he branded and patented it and build a successful commercial business on it.

The time they gave fits the timeline so far developed in this article perfectly.  The restrictions on the use of saltpeter in Germany came into effect soon after August 1914 and on the basis of the work of German scientists Polenski (1891), Kisskalt and Lehmann (1899) sodium nitrite was authorised for use in curing brines.  Ladislav NACHMÜLLNER, a master butcher in Prague saw the way that the potentially lethal nitrite could be mixed with sodium chloride (and possibly sugars, as was the practice during this time).

This identifies NACHMÜLLNER as one of the pioneers of one of the first commercial curing brine that incorporated sodium nitrite.   During the initial translation from the book on Praganda, Monica and her husband, Mike Werner also confirmed another important clue namely that many copy-cat products soon appeared on the market.  NACHMÜLLNER was not just one producer of many.  He was a leading producer and the timeline suggest, one of the first.

This is also confirmed by the fact that we know that by 1917 many proprietary curing brines were being sold throughout Europe and as far as the United States that contained sodium nitrite.

Praganda

It is therefore easy to see that The Griffith Laboratories bought their Prague Salt either from NACHMÜLLNER’s company directly or from one of his competitors in Prague or from one of several others who sprang up in that region as a result of the success of Praganda.  This may well have been through a sales agent or wholesaler in Germany or from a copy producer in Germany itself.  Any of these alternatives would fit the reference in Griffith’s documents that Prague Salt was procured from Germany.

It is also easy to see that Prague Powder was a good trade name to use in the USA due to the high regard around the world for Prague Hams during this time.  If indeed Griffith bought it from NACHMÜLLNER, Prague Powder would have been a much better name for the US market than Praganda.  The fact however stands that one of the pioneers of the curing salt known as Praganda and the curing salt known as Prague Powder was in fact Ladislav NACHMÜLLNER.  This is true whether it was bought from NACHMÜLLNER or from a competitor who copied Praganda, either in Prague or in Germany.

It provided the answer that evaded me for years.  Who invented Prague Powder and where does the name come from?  Until we have an actual sales receipt from NACHMÜLLNER’s company to The Griffith Laboratory or any other company from that matter, it will remain a matter of conjecture, but narrowing it down to Ladislav NACHMÜLLNER and his company puts us in the right region, during the right time related to the invention of the curing salt.  It makes NACHMÜLLNER one of the pioneers of what was sold in America, 10 years later as Prague Powder.

In the meantime Prof. Pipek continued to try and make contact with NACHMÜLLNER’s daughter who has not been taking any telephone calls.  On 22 June we got word that she just turned 90 and no longer receive visitors.  She is very ill and in a frail care facility.

This article will be followed up by a series of articles intended to bring the story of the invention of Praganda to the world.

Krasne

Conclusion

The history of the use of nitrite in curing brines is one of the most fascinating stories within the story of bacon.  Center stage to the development of curing mixes that became commercially available throughout the world is the invention by Ladislav NACHMÜLLNER.  The story became very human with the news from Prof. Pipek about the frailty of Eva.  The entire meat processing community wish to express our admiration to NACHMÜLLNER and thanks to his daughter for keeping the memory of her father alive.  We salute you for a life well lived.

Special thanks:

Special thanks goes to Prof. Ing. Petr Pipek for his personal interest, support and contribution to this story.  To Jan Katina, the director of the Czech Association of Meat Processors, for his personal contribution and interest in the efforts of bringing this story to the world.  To Monica and Mike Werner for translating vital information from the Czech language.  Thanks to the Griffith Laboratory who has provided us with valuable information and who remain interested in the story.  To Crown National for their interest in the story and support of the project.  To the owners, directors and management team of Woodys Consumer Brands (Pty) Ltd. who continue to support this project with encouragements and advice.  To Ing. Alice Roháčková from K+S Czech Republic for the information provided. To the historian and author, Maureen Ogle for the encouragement and references and Lisa Keefe, the Editor of Meatingplace for being a treasure of information and a never ending source of references.   To Kristian Nielsen from Azelis, Denmark, who are always eager to contribute and offer encouragement.  Christian Schiess from the company Geiger and Klotzbucher (Pty) Ltd. who are always ready to assist with contacts in Europe who may be able to help.  To Peter Birkelund and friends from Danish Crown who are verifying information from their side in order to improve the body of evidence and seek verification from their own sources.  Finally and most importantly for the family of  Ladislav NACHMÜLLNER, for conveying our good wishes to Eva and for the opportunity to get much more information from you.

——————

(c) eben van tonder

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References:

Brown, Howard Dexter et al.  1946. Frozen Foods: Processing and Handling

The Indiana Gazette, 28 March 1924

Ladislav Nachmüllner vulgo Praganda,  Nachmüllnerová, Eva Editor, Nakladatelské údaje: Tábar : OSSIS, 2000

Lauer K. 1991.  The history of nitrite in human nutrition: a contribution from German cookery books.  Journal of clinical epidemiology. 1991;44(3):261-4.

Lück, E. and Jage, M.  1980.  Antimicrobial Food Additives: Characteristics – Uses – Effects.  Springer.

Prague Powder, Its uses in modern Curing and processing.  1963.  The Griffith Laboratories, Inc.

The Food Packer.  Vance Publishing Corporation. 1954

http://www.elmswell-history.org.uk/arch/firms/baconfactory/baconfactory.html

US 1259376 A, https://www.google.com/patents/US1259376

https://en.wikipedia.org/wiki/K%2BS

Images:

Image 1:  Prague.  www.bjtonline.com/business-jet-news/prague

Image 2:  Old Prague.  https://culturemorph.wordpress.com/category/photography-2/page/2/

Image 3:  Prague Bridges.  “Praha Bridges”. Licensed under Public Domain via Wikimedia Commons – https://commons.wikimedia.org/wiki/File:Praha_Bridges.JPG#/media/File:Praha_Bridges.JPG

Image 4:  Prague 1910.  http://forargyll.com/2010/07/battle-over-franz-kafka%E2%80%99s-papers-and-the-scottish-and-argyll-connections/

Image 5:  Prague.  http://www.radio.cz/en/static/kafka/3place

Image 6:  Prague Square.  https://culturemorph.wordpress.com/category/photography-2/page/2/

Image 7:    Ladislav NACHMÜLLNER from vulgo Praganda.

Image 8:  Prof Pipek holding Vulgo Praganda.  Pic by himself.

Image 9:  Monica, holding Vulgo Praganda.  Pic by Eben.

Image 10:  Trade Mark.  From Vulgo Praganda.

Image 11:  Eva.  Image sent to Eben by Prof Pipek.

Concerning the direct addition of nitrite to curing brine

by Eben van Tonder

This article is available for download in pdf: Concerning the direct addition of nitrite to curing brines

See, Bacon & the Art of Living,

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

Chapter 11.04: The Direct Addition of Nitrites to Curing Brines – The Spoils of War

ebenvt bacon belly ebenvt Prague Powder

Introduction

Bacon and the art of living is a study in the birth of the elements of bacon curing.  Neither the chemical reactions, nor the different mechanical processes are simple.  Everything about bacon is complex and beautiful.  One of the most amazing stories within the grand story of bacon, is the story of sodium nitrite.

Pork is changed into bacon by the reaction of nirtrite (NO2-).  With salt, it is the curing agent.  The meat industry uses nitrite in the form of an ionic compound, sodium nitrite.  It is sold as Quick Cure or Insta’ Cure, Prague Salt, Prague Powder or simply Pink Salt or Curing Salt.  It is coloured pink to distinguish it from ordinary salt (sodium chloride).  Every spice company sells it.  It is the essential ingredient in the meat curing process.

Meat changes colour from the red fresh meat colour to an unappetising brown colour within days. (1)  If one injects nitrite into the meat or rubs a mixture of salt and a small percentage of nitrite onto it, the meat will develop an appatizing reddish/ pinkish fresh meat colour (Hoagland, Ralph.  1914) and a characteristic cured taste.  It will retain this colour for weeks and months if packed in the right conditions.  (1)  Nitrite provides an indispensable hurdle against a particularly nasty food pathogen, clostridium botulinum.  It also endows the meat with a distinct cured taste.

During ages past, it has however not been nitrite that was added to meat to accomplish this, but its cousin, nitrate (NO3-).  They may be cousins, but are very different in characteristics. Nitrate takes several weeks or even months to cure meat where nitrite accomplishes the same task in 12 hours.  How the change happened from using nitrate or salpeter in meat curing to nitrite is an epic story.

Overview

This article tracks the migration of the meat industry from the use of saltpeter (potassium or sodium nitrate) as curing agent to sodium nitrite.  It gives an overview of the scientific discoveries which started to reveal the mechanisms of meat curing.   This understanding lead to the realisation that a direct application of nitrite as the curing agent will be vastly superior to the use of saltpeter (nitrate).

This was a dramatic discovery since in the late 1800’s and early 1900’s, the world saw nitrite as a dangerous drug at best and a poison that polluted drinking water and cause death of cattle.  Using this directly in food and meat curing was unthinkable.

Sodium nitrite was available in this time for application in the coal-tar dye and medical industries.  Science and engineering have however not worked out its large scale production in a way that will make it a commercially viable proposition for direct use in meat curing from a price and availability perspective.

World War One provided the transition moments required to change everything.  Germany invested heavily in nitrogen related technology for the war.  The most organised scientific and engineering environment on the planet in the early 1900’s focused its full attention on overcoming the manufacturing challenges in the service of the manufacturing of munitions.  It also required this technology to overcome the challenge of being cut off, as a result of the war, from the natural sodium nitrate deposits in Chili that it required as fertilizer to drive its enormous agriculture sector during the war.  At the same time, the use of saltpeter in meat curing was prohibited under the leadership of Walther Rathenau so that the valuable nitrate could be reserved for manufacturing of munitions.

This prohibition, I believe, was the initial spark that caused butchers to change to the use of sodium nitrite.  At the same time, sodium nitrite was being produced in large volumes since it had, in its own right, application in the manufacturing of explosives.  Health concerns and probably the need to have it reserved for munitions, lead to a ban, similar to nitrate, on its use in meat curing.  So, World War One solved the scientific challenges of large scale manufacturing of sodium nitrite, the engineering challenges of building production facilities and provided the impetus for the meat industry to change by banning the use of saltpeter in meat curing.  The ban was lifted after the war.

Following the war, Germany had to find markets for its enormous war time chemical stock piles.  One of the ways it “sold” sodium nitrite was as a meat curing agent based on its inherent benefits of curing consistency and the vastly shorter curing time required.

It was introduced to the world mainly through the Chicago based firm, Griffith Laboratories, who imported it as Prague Salt from Germany and later improved on it by fusing the sodium nitrite to sodium chloride and sold it as Prague Powder.

Early humans to Polenski (1891)

Early humans did not know they added nitrate to the meat.  A mixture of salt and a small amount of saltpeter was used to cure meat in order to preserve it and to retain the fresh meat colour.

Saltpeter is found naturally around the world in typically dry areas.  Deposits exist in India, China, Mexico, the USA, and the Middle East.  Despite its wide occurrence, the concentration of natural saltpeter is low.  (Whittaker, CW, 1932: 10)

Saltpeter is also made by human effort.  Europe, particularly Germany and France, Great Britain, India and the United States all acquired the technology to produce satpeter.  (Van Cortlandt, P, 1776:  7, 8)

In South Africa, saltpeter deposits are found in the Griquatown beds of the Transvaal geological system.  It extends from just South of the Orange River Northwards to the Kalahari Desert and then Eastwards into the Old Transvaal from Zeerust to Polokwane. The nitrate deposits occur in the middle portions of these beds, in softer and more decomposed shale.  These South African reserves have fortunately never been mined even though it was used on a small scale to make gunpowder for the old Boer government.  (Whittaker, CW, 1932: 10)

Saltpeter was at the heart of the arms race of the middle ages.  It was used mainly in gunpowder, but as the worlds population grew, it became indispensable as a fertilizer and for curing meat. (See Bacon and the art of living, chapters 2, 3 and 4)

The French chemist, Antoine Lavoisier worked out its chemical composition.  It is an ionic compound consisting of the metal potassium and its power is nitrate.  Potassium Nitrate.  (Mauskopf, MSH.  1995:  96)  Trade in Saltpeter around the world was done through companies such as the Dutch East Indian Company (Dutch abbreviation, VOC) who traded it for its main use as an ingredient in gunpowder.  It was by volume one of the largest commodities traded by the Dutch East Indian Company who set up the trading post in 1652 that became Cape Town.  

Major developments shifted the balance of power away from Indie, China and home grown saltpeter production to South America where huge deposits of sodium nitrate were discovered that would become the principal source of the worlds nitrate for much of the 1800’s.

A man walks down a dirt road in the Atacama Desert. Despite being one of the most inhospitable places on earth, the Atacama is still mined: in 2010 this made world-wide news, when the Copiapó mining accident led to the dramatic rescue of 33 trapped miners (AP Photo/Dario Lopez-Mills).
A man walks down a dirt road in the Atacama Desert. Despite being one of the most inhospitable places on earth, the Atacama is still mined: in 2010 this made world-wide news, when the Copiapó mining accident led to the dramatic rescue of 33 trapped miners (AP Photo/Dario Lopez-Mills).

A popular legend tells the story of the discovery by two Indians in the Atacama desert in the South of Peru.  According to the legend, after a hard day’s work, they camped in the Pampa and started a campfire to warm themselves.  All of a sudden the ground started to burn and they ran away, thinking that they have seen the devil.  They reported the event later to a priest in Camina who returned to the site.  He had it analysed and found it to contain sodium nitrate (the same power as potassium nitrate, but linked to another common metal).  The priest, according to the story, threw the rest of the soil in the courtyard of his house and saw the plants grew vigorously.  He recommended the soil as an excellent tonic for the plant kingdom.  (Wisniak, J, et al., 2001 :433)

So was discovered the enormous sodium nitrate deposits of the Atacama desert. The fertilizer properties of the salt was known long before the 1600’s.   There are references to saltpeter and the nitrate ground in 1604.  During the time of the Spanish Conquest, in the 1700’s, miners working in the South of Peru realised that gunpowder could be manufactured from the material in the soil instead of potassium nitrate.  (Wisniak, J, et al., 2001 :433)

A report published in 1803 by Juan Egana, Secretary of the Royal Court of Mines in Chile showed the Huasco region is “covered in a large part by a crust of niter salt, well crystallized, and several inches thick” (Wisniak, J, et al., 2001 :434)

The region was developed and by 1850 exports reached 24 000 tons/ year.  In 1910 it was 2.4 million tons per year and by 1916, 3 million tons per year from 97 plants. (Wisniak, J, et al., 2001 :434)

By the beginning of the 1900’s the country buying the largest quantity of the Chilean saltpeter was Germany (Wisniak, J, et al., 2001 :434) who used it aggressively in their agriculture sector as fertilizer.

There is a close correlation between sodium and potassium nitrate.  Its difficult to distinguish between sodium and potassium nitrate just by tasting it.  Scientists were able to distinguish between the two compounds from the mid 1600’s and knew that sodium nitrate had a much greater ability to attract water (Whittaker, CW, 1932:  3).  This made sodium nitrate a much better curing agent than potassium nitrate.

Nitrite was described in 1864 by the English Physiologist, B. W. Richardson.  He outlined how to manufacture it and its chemical properties.  (Wells, D. A., 1865:  233)  Much earlier, in 1777 the prolific Swedish chemist Scheele, working in the laboratory of his pharmacy in the market town of Köping, made the first pure nitrite. (Scheele CW. 1777)   He heated potassium nitrate at red heat for half an hour and obtained what he recognized as a new “salt.” The two compounds (potassium nitrate and nitrite) were characterized by Péligot and the reaction established as 2KNO3→2KNO2+O2. (Péligot E. 1841: 2: 58–68) (Butler, A. R. and Feelisch, M.)

The technology existed in the 1800’s to not only produce potassium nitrate (salpeter) and nitrite, but to also test for these.

Remember that curing up till 1890 has been attributed to saltpeter (potassium nitrate) or Chilean saltpeter (sodium nitrate).  In 1891 a German food scientist, Dr Ed Polenski, working for the German Department of Health made an observation that would change the world while studying curing brines.  When he tested the curing brine made from saltpeter and salt, days after it was made, he found nitrite to be  present.  This was surprising since saltpeter is potassium or sodium nitrate, not nitrite.

Dr Ed speculated that the nitrate (NO3-) was changed into nitrite (NO2-) through bacterial action, a reduction step between nitrate and nitrite that was well understood by this time.  He had a hunch that nitrite is responsible for curing of meat and not the nitrate directly, as was previously thought.

From Polenski (1891) to WWI (1914 to 1918)

world war 1

Following Dr Ed’s observations in 1891, considerable resources from around the world were dedicated to understand the chemistry of meat curing.

When World War One broke out, the concept of nitrite as curing agent (as opposed to nitrate) was firmly established.

Ralph Hoagland, Senior Biochemist, Biochemie Division, Bureau of Animal Industry, United States Department of Agriculture, published an article in 1914, Coloring matter of raw and cooked salted meats.  In this article, he shows that nitrite as curing agent was a known and accepted fact by the outbreak of World War One (Hoagland, Ralph.  1914)

Readers who dont have an interest in the detailed description of the key discoveries may want to skip over the rest of this section altogether or glance over it generally.  The goal of the section is to give the reader a sense of how firmly and universally the concept of nitrite as the curing agent was established by 1914.  In the midst of the technical names and jargon, don’t lose the sense of the universal interest.  The 1700’s, 1800’s and beginning of the 1900’s was a time when the average person was as interested in chemistry as we are today about communication and information technology.

The difference between nitrates and nitrites, for example, was taught in school curriculum. An article appeared in the Daily Dispatch in Brainerd, Minnesota in the 20’s, that gives as an example of a diligent high school student, that he or she would know the difference.    (The Brainerd Daily Dispatch (Brainerd, Minnesota).  17 January 1923.  Page 3.)

Following Dr. Polenski’s observation, the German scientist, Notwang confirmed the presence of nitrite in curing brines in 1892, as observed by Dr Polenski, but attributed the reduction from nitrate to nitrite to the meat  tissue itself.  The link between nitrite and cured meat colour was finally established in 1899 by another German scientist, K. B. Lehmann in a simple but important experiment.

Karl Bernhard Lehmann (September 27, 1858 – January 30, 1940) was a German hygienist and bacteriologist born in Zurich.

In an experiment he boiled fresh meat with nitrite and a little bit of acid.  A red colour resulted, similar to the red of cured meat.  He repeated the experiment with nitrates and no such reddening occurred, thus establishing the link between nitrite and the formation of a stable red meat colour in meat. (Lee Lewis, W., 1925: 1243)

In the same year, another German hygienists, K. Kisskalt, confirmed Lehmann’s observations but proved that the same red colour resulted if the meat was left in saltpeter (potassium nitrate) for several days before it was cooked. (Lee Lewis, W., 1925: 1243)

K. B. Lehmann made another important observation that must be noted when he found the colour to be soluble in alcohol and ether and to give a spectrum showing an absorption band just at the right of the D line, and a second band, often poorly defined, at the left of the E line. On standing, the color of the solution changed to brown and gave the spectrum of alkaline hematin, the colouring group (Hoagland, Ralph.  1914).

The brilliant British physiologist and philosopher, John Scott Haldane weighed in on the topic.  He was born in 1860 in Edinburgh, Scotland. He was part of a lineage of important and influential scientists.  (Lang, M. A. and Brubakk, A. O. 2009.  The Haldane Effect)

J. S. Haldene contributed immensely to the application of science across many fields of life.  This formidable scientist was for example responsible for developing decompression tables for deep sea diving used to this day.  (Lang, M. A. and Brubakk, A. O. 2009.  The Haldane Effect)

“Haldane was an observer and an experimentalist, who always pointed out that careful observation and experiments had to be the basis of any theoretical analysis. “Why think when you can experiment” and “Exhaust experiments and then think.” (Lang, M. A. and Brubakk, A. O. 2009.  The Haldane Effect)

An interesting anecdote is told about him from the time when he was studying medicine  in Jena.  He apparently carefully observed the amount of beer being drunk, noting that the students on the average drank about 20 pints per evening.”  (Lang, M. A. and Brubakk, A. O. 2009.  The Haldane Effect)

Before we look at Haldene’s contribution, let us re-cap what has been determined thus far.

Polenski and Notwang discovered that nitrite were present in a mix of saltpeter and salt, after a while, even though no nitrite were present when the brine was mixed.

Karl Bernhard Lehmann linked nitrite conclusively with the reddening effect of fresh meat that was boiled in a nitrite and water solution with some free acid.  He also showed that this does not happen if fresh meat is placed in saltpeter and water solution and boiled immediately.   K. Kisskalt showed that the same reddening occurred if fresh meat is left in saltpeter for some time.

K. B. Lehmann managed to “isolate” the colour by dissolving it in ether and alcohol and analyze it spectroscopically.

What S. J. Haldele did was to apply the same rigor to cured meat and became the first person to demonstrate that the addition of nitrite to hemoglobin produce a nitric oxide (NO)-heme bond, called iron-nitrosyl-hemoglobin (HbFeIINO). (Lang, M. A. and Brubakk, A. O. 2009:  119)

Nitrite is further reduced to nitric oxide (NO) by bacteria or enzymatic reactions and in the presence of muscle myoglobin forms iron-nitrosyl-myoglobin. It is nitrosylated myoglobin that gives cured meat, including bacon and hot dogs, their distinctive red color and protects the meat from oxidation and spoiling. (Lang, M. A. and Brubakk, A. O. 2009: 119)

This is how he did it.  He concluded (1901) that its red colour is due to the presence of the nitricoxid hemochromogen resulting from the reduction of the coloring matter of the uncooked meat, or nitric-oxid hemoglobin (NO-hemoglobin). (Hoagland, Ralph.  1914)

Remember the observation made by K. B. Lehmann that the colour of fresh meat cooked in water with nitrites and free acid to give a spectrum showing an absorption band just at the right of the D line, and a second band, often poorly defined, at the left of the E line.  (Hoagland, Ralph.  1914)

Haldene found the same colour to be present in cured meat.  That it is soluble in water and giving a spectrum characteristic of NO-hemoglobin. The formation of the red color in uncooked salted meats is explained by the action of nitrites in the presence of a reducing agent and in the absence of oxygen upon hemoglobin, the normal coloring matter of fresh meats. (Hoagland, Ralph.  1914)

Ralp Hoagland (1908) studied the action of saltpeter upon the colour of meat and found that its value as an agent in the curing of meats depends upon the nitrate’s reduction to nitrites and the nitrites to nitric oxid, with the consequent production of NO-hemoglobin.  The red colour of salted meats is due to this compound.  Hoagland conclusively shows that saltpeter, as such, has no value to preserve the fresh colour. (Hoagland, Ralph,  1914: 212)

The reason why the knowledge did not translate to a change in curing brines was very simple.  The technology and infrastructure did not exist to produce enough nitrite commercially to replace saltpeter.  This means that to produce nitrite was very expensive.

There were some attempts to capitalise on the knowledge gained.  The German scientist,  Glage (1909) wrote a pamphlet where he outlines the practical methods for obtaining the best results from the use of saltpeter in the curing of meats and in the manufacture of sausages. (Hoagland, Ralph,  1914: 212, 213)

Saltpeter can only effect the colour of the meat if the nitrate in the saltpeter is reduced to nitrite.  Glage gives for the partial reduction of the saltpeter to nitrites by heating the dry salt in a kettle before it is used.  It is stated that this partially reduced saltpeter is much more efficient in the production of color in the manufacture of sausage than is the untreated saltpeter. (Hoagland, Ralph,  1914: 212, 213)

The fear of nitrites

The lack of a large scale production process for sodium nitrite and the engineering to build these plants were however not the only factors preventing the direct use of sodium nitrite in meat curing brines.  As one review literature from the late 1800’s and early 1900’s, one realises that a major hurdle that stood between the use of sodium nitrites in meat curing was the mistrust by the general public and authorities of the use of nitrites in food.  The matter relate to the high level of toxicity of nitrite, a matter that will be dealt with separately in Bacon and the art of living.

The first recorded direct use of nitrite as a curing agent was in 1905 in the USA where it was used in secret. (Katina, J.  2009)   The USDA finally approved its use as a food additive in 1906. (porkandhealth)  This did not mean that the public would accept it.

Sodium Nitrite started to be used in this time as a bleach for flour in the milling industry.  Several newspaper articles reveal public skepticism and the great lengths that the scientific community and industry had to go to in order to demonstrate its safety as a bleaching agent  for flour.  An article appeared in The Nebraska State Journal Lincoln, Nebraska on 29 June 1910 entitled,  “All for bleached flour.  No harm can come from its consumption says experts”.  The article deals with a federal court case about the matter and interestingly enough, it seems from newspaper articles that the government was opposing its use.  Many other examples can be sited.

There is a 1914 reference in the London Times that shows the general view of nitrite as not just restricted to the USA.  The article appeared on 9 June 1914 and a reference is made to sodium nitrite where it is described as “a dangerous drug with a powerful action on the heart.”  (The London Times. 1914.  Page 118)  The reference was to the use of nitrite for certain heart conditions.

It is interesting that sodium nitrite did not find an immediate application in the meat industry, even after it was allowed in 1906 in the USA.

In my view, this points to problems surrounding availability and price.  If the issue was the public perception alone, this could have been overcome with a PR campaign by the meat industry as was successfully done by the milling industry.

On 13 Dec 1915 George F. Doran from Omaha, Nebraska,  filed an application for a patent for a curing brine that contained nitrites.  His application strengthens the evidence that it was not the knowledge of nitrite and its role in curing that was lacking, but availability and price.  He states the objective of his patent application to “produce in a convenient and more rapid manner a complete cure of packing house meats; to increase the efficiency of the meat-curing art; to produce a milder cure; and to produce a better product from a physiological standpoint.”

One of Doran’s sources of nitrite is “sterilized waste pickling liquor which he [I have] discovered contains soluble nitrites produced by conversion of the potassium nitrate, sodium nitrate, or other nitrate of the pickling liquor when fresh, into nitrites. . .”   “Waste pickling liquor is taken from the cured meats.  Nitrites suitable for use in carrying out the present invention may be produced by bacterial action from nitrates and fresh pickling liquor by adding a small percentage of old used pickling liquor. The bacteria in old pickling liquor are reducing bacteria and change nitrates to nitrites.”  (Process for curing meats. US 1259376 A)

The use of old pickle has been described much earlier than Doran’s patent.  His usage of old pickle when he understood the reduction of nitrate to nitrite and nitrite’s role in curing along with the fact that sodium nitrite was available can point to only one reason – price.   It comes 10 years after sodium nitrite was first tested in curing brines for meat and shows that it has never become the curing agent of choice most probably due to limited availability and price.  Much more about this later.

The post WWI era (1918 and beyond)

US troops marching

After WWI something changed.  Saltpeter (potassium or sodium nitrate) has been substituted by the direct addition of nitrite to the curing brines.

The question is who pioneered this.  Why and how did sodium nitrite production become so commonplace that it became available to bacon curing plants around the world?

Industry developments like this do not happen “by itself.”  Someone  drives it in order for it to become general practice in an industry.

Chilean Saltpeter is a good case in point.  Even though natural sodium nitrate deposits were discovered in the Atacama desert, it took a considerable effort on the side of the producers (mainly the Chilean Government) to work out the benefits of sodium nitrate and to market it to the world.  It is, for example, famously reported that the first shipment to Britain was dumped in the sea before the ship docked on account that the cargo attracted customs duty and the ships owners could not see any commercial application for sodium nitrate. (2)

In the same way, the direct application of nitrite in curing brines must have been driven by someone.

The Griffith Laboratories, Inc.

The Chicago based company of Enoch Luther Griffith and his son, Carroll Griffith started to import a mixture of sodium nitrite and salt as a curing substitute for saltpeter from Germany in 1925.  The product was called Prague Salt (Prague Powder, 1963: 3)

The Griffith Laboratories (3) played a key role in marketing the new curing brine in the USA.    They took the concept of the Prague Salt (sodium nitrite) and in 1934 announced an improved curing brine, based on the simple use of sodium nitrite, where they fuse nitrite salt and sodium chloride in a particular ratio.  They called it Prague Powder.  Their South African agents, Crown Mills (4), brought the innovation to South Africa. (Prague Powder, 1963: 3, 4)

It is fair to assume that if Prague Salt was being sold to Griffith in the 1920’s, the German producers must have sold it to other countries and companies around the world also.

The benefits of Prague Salt and later Prague Powder over Saltpeter is dramatic.  Prague Salt (sodium nitrite) does not have the slightly bitter taste of saltpeter (Brown, 1946:  223).  It allows for greater product consistency since the same percentage of nitrate was not always present in the saltpeter and the reduction of nitrate to nitrite takes longer or shorter under various conditions (Industrial and Engineering Chemistry, December 1925: 1243).  The big benefit was however in the curing time required.  Instead of weeks or even months that is required with saltpeter, curing could now be done in days or even hours with sodium nitrite.  (The Food Packer, 1954:  64)  From there, brand names like Quick Cure or Instacure.

This means that we have narrowed the time line for invention of Prague Salt (Sodium Nitrite) to between 1914, the beginning of the Great War and 1925 when Griffith imported it from Germany.

However, a document, published in the USA in 1925 shows that sodium nitrite as curing agent has been known well before 1925.

The document  was prepared by the Chicago based organisation, The Institute American Meat Packers and published in December 1925.  The Institute  started as an alignment of the meat packing companies set up by Phil Armour, Gustavus Swift, Nelson Morris, Michael Cudahy, Jacob Dold and others with the University of Chicago.

A newspaper article about the Institute sets its goal, apart from educating meat industry professionals and new recruits, “to find out how to reduce steers to beef and hogs to pork in the quickest, most economical and the most serviceable manner.”   (The Indiana Gazette.  28 March 1924).

The document is entitled, “Use of Sodium Nitrite in Curing Meats“, and it it is clear that the direct use of nitrites in curing brines has been practiced from earlier than 1925. (Industrial and Engineering Chemistry, December 1925: 1243)

The article begins “The authorization of the use of sodium nitrite in curing meat by the Bureau of Animal Industry on October 19, 1925, through Amendment 4 to B. A. I. Order 211 (revised), gives increased interest to past and current work on the subject.”

Sodium Nitrite curing brines would therefore have arrived in the USA, well before 1925.

It continues in the opening paragraph, “It is now generally accepted that the salpteter added in curing meat must first be reduced to nitrite, probably by bacteria, before becoming available as an agent in producing the desirable red color in the cured product.  This reduction is the first step in the ultimate formation of nitrosohemoglobin, the color principle.  The change of nitrate to nitrite is by no means complete and varies within considerable limits under operating conditions.  Accordingly, the elimination of this step by the direct addition of smaller amounts of nitrite means the use of less agent and a more exact control.”

Griffith describes the introduction and origin of Prague Salt and later, Prague Powder as follows in official company documents:

The mid-twenties were significant to Griffith as it had been studying closely a German technique of quick-curing meats.  Short on manpower and time, German meat processors began curing meats using Nitrite with salt instead of slow-acting saltpeter, potassium nitrate. This popular curing compound was known as “Prague Salt.”  (Griffith Laboratories Worldwide, Inc.)

The World War One link

The tantalizing bit of information from Griffith sets World War One as the background for the practical and large scale introduction of direct addition of nitrite into curing brines through sodium nitrite.

There has to be more to the reason for saltpeter being replaced by sodium nitrite as curing agent than the reasons given by Griffith.  For starters, the meat industry has always been under pressure to work fast with less people due to pressure on profit margins.  The need to cure meat quicker due to short manpower and time as a result of the war could not be the full story.

The World War One link from Griffith does not give all the answers, but it puts the introduction of sodium nitrite to meat curing between 1914 and 1918, at least 7 years before Griffith started to import Prague Salt.

A document from the University of Vienna would fill out the story.  According to it, saltpeter was reserved for the war effort and was consequently no longer available as curing agent for meat during World War One. (University of Vienna). It was reserved for the manufacturing of explosives, and for example, the important industry of  manufacturing nitrocellulose, used as base for the production of photographic film, to be employed in war photography.  (Vaupel, E.,  2014: 462)  It gets even better.  Not only did the prohibition on the use of saltpeter expand the information from Griffith as to why people started using sodium nitrite (macro movements in culture does not take place because of one reason only), but it provide a name to the prohibition.

In August 1914, the War Raw Materials Department (Kriegsrohstoffabteilung or KRA) was set up under the leadership of Walther Rathenau.  It was Rathenau who was directly responsible for the prohibition on the use of salpeter.  (5)  He therefore is the person in large part responsible creating the motivation for the meat industry in Germany to change from saltpeter to sodium nitrite as curing medium of choice for the German meat industry during Wold War One.

Walter Rathenau’s actions may have motivated the change, but it was the developments in synthesizing ammonia, sodium nitrate and sodium nitrite which provided the price point for the compound to remain the curing agent of choice, even after the war and after the prohibition on the use of saltpeter was lifted.

Atmospheric Nitrogen

One of the most important scientific riddles to be solved in the late 1800’s/ early 1900’s was how to produce ammonia and its related chemicals from atmospheric nitrogen.  Sir William Crookes delivered a famous speech on the Wheat Problem at the annual meeting of the British Association for the advancement of Science in 1898.

In his estimation, the wheat production following 1897 would seriously decline due to reduced crop yields, resulting in a wheat famine unless science can step in and provide an answer.  He saw no possibility to increase the worlds wheat yield under the prevailing agricultural conditions and with the increase in the world population, this posed a serious problem.  He said,  “It is clear that we are taxed with a colossal problem that must tax the wits of the wisest.”  He predicted that the USA who produced 1/5th of the worlds wheat, would become a nett importer unless something change.  He pointed to the obvious answer of manure, but observed that all available resources  are being depleted fast.

Sir William saw a  “gleam of light in the darkness” and that “gleam” was atmospheric nitrogen.  (Otago Witness.  3 May 1900, Page 4)

It was the German Chemist, Fritz Harber who solved the problem, with the help of Robert Le Rossignol who developed and build the required high pressure device to accomplish this. (www.princeton.edu)

In 1909 they demonstrated that they could produce ammonia from air, drop by drop, at the rate of about a cup every two hours.  “The process was purchased by the German chemical company BASF (a coal tar dye supplier), which assigned Carl Bosch the difficult task of scaling up Haber’s tabletop machine to industrial-level production.  Haber and Bosch were later awarded Nobel prizes, in 1918 and 1931 respectively, for their work in overcoming the chemical and engineering problems posed by the use of large-scale, continuous-flow, high-pressure technology.”  (www.princeton.edu)

“Ammonia was first manufactured using the Haber process on an industrial scale in 1913 in BASF’s Oppau plant in Germany.”  (www.princeton.edu)

It was the vision and leadership of Walther Rathenau, the man responsible for restricting the use of saltpeter, that drove Germany to produce synthesized Chilean Saltpeter.  He saw this as one of the most important tasks of his KRA.  He said:  “I initiated the construction of large saltpeter factories, which will be built by private industries with the help of governmental subsidies and will take advantage of recent technological developments to make the import of saltpeter entirely unnecessary in just few months“.  (Lesch, J. E.,  2000:  1)

Fritz Harber was one of the experts appointed by Rathenau to evaluate a study on the local production of nitric acid.

During World War One production was shifted from fertilizer to explosives, particularly through the conversion of ammonia into a synthetic form of Chile saltpeter, which could then be changed into other substances for the production of gunpowder and high explosives (the Allies had access to large amounts of saltpeter from natural nitrate deposits in Chile that belonged almost totally to British industries; Germany had to produce its own). It has been suggested that without this process, Germany would not have fought in the war, or would have had to surrender years earlier.”  (www.princeton.edu)

So it happened that Germany became the leader in the world in synthesised sodium nitrate production and it effectively replaced its reliance on saltpeter from Chile with sythesised  sodium nitrate, produced by BASF and other factories.

So, as a result of the First World War, sodium nitrite was produced at levels not seen previously in the world and in large factories that was build, using the latest processing techniques and technology from a scientific and an engineering perspective.  Sodium nitrite, like sodium nitrate was being used in the production of explosives.  Nitroglycerin is an example of an explosive used extensively by Germany in World War One that uses sodium nitrite in its production.  (Wikipedia.org.  Nitroglycerin and  Amyl Nitrite)

Ball-and-stick model of Amyl nitrite used in the production of nitroglycerin. Amyl nitrite is produced with sodium nitrite. The diagram shows the amyl group attached to the nitrite functional group.
Ball-and-stick model of Amyl nitrite used in the production of nitroglycerin. Amyl nitrite is produced from sodium nitrite. The diagram shows the amyl group attached to the nitrite functional group.

Sodium nitrite and the coal-tar dye industry

The importance of the manufacturing cost of nitrite and the matter surrounding availability can be seen in the fact that sodium nitrite has been around since well before the war.  Despite the fact that it was known that nitrite is the curing agent and not nitrate, and despite the fact that sodium nitrite has been tested in meat curing agents, probably well before the clandestine 1905 test in the USA,  it did not replace saltpeter as the curing agent of choice.  My hunch is that it did not enter the meat industry as a result of cost.

The technology that ultimately is responsible for synthesising Chilean Saltpeter and made low cost sodium nitrite possible was being incubated in the coal-tar dye and textiles industry and in the medical field.  The lucrative textiles and dye industry was the primary reason for German institutions of education, both in science and engineering to link with industry, resulting in a strong, well organised skills driven German economy. For example, “Bayer had close ties with the University of Göttingen, AGFA was linked to Hofmann at Berlin, and Hoechst and BASF worked with Adolph Baeyer who taught chemists in Berlin, Strasbourg, and Munich.” (Baptista, R. J..  2012:  6)

“In the late 1870s, this knowledge allowed the firms to develop the azo class of dyes, discovered by German chemist Peter Griess, working at an English brewery, in 1858.  Aromatic amines react with nitrous acid to form a diazo compound, which can react, or couple, with other aromatic compounds.” (Baptista, R. J..  2012:  6)

Nitrous acid (HONO) is to nitrite (NO2-) what nitric acid (NO3) is to nitrate (NO3-).

According to K. H. Saunders, a chemist at Imperial Chemical Industries, Ltd., Martius was the chemist to whom the introduction of sodium nitrite as the source of nitrous acid was due.   (Saunders, K. H., 1936:  26)

The economic imperative

The simple fact is that ammonia can be synthesized through the direct synthesis ammonia method at prices below what can be offered through Chilean Satlpeter.  (Ernst, FA.  1928: 92 and 100)  Sodium Nitrite can be supplied at prices below Chilean saltpeter and this made sodium nitrite the most effective curing agent at the lowest price since World War One.

As an example of the cost differences, the price of Nitric Acid (HNO3) from direct synthesis in 1928 was $23.60 per ton HNO3 plus the cost of 606 lb. of NH3 by-product  and from Chilean Nitrate at $32.00 per ton of HNO3, plus the cost of 2840 N NO3 by-product.  (Ernst, FA.  1928: 112)

The advantage of scale and technology

By 1927, Germany was still by far the worlds largest direct syntheses ammonia producer.  Production figures of the year 1926/ 1927  exceeded Chilean saltpeter exports even if compared with the highest levels of exports that Chilean saltpeter ever had in 1917.  A total of 593 000 tons of nitrogen was fixed around the world in 1926/27.  Of this figure, Germany produced 440 000 tons or 74%.  The closest competitor was England through the Synthetic Ammonia and Nitrates Ltd. with a total capacity of 53 000 tons of nitrogen per year.  (Ernst, FA.  1928: 119, 120)

In the USA 7 direct synthesis plants were in operation with a combined capacity of 28 500 tons of nitrogen per year.  (Ernst, FA.  1928: 120)

Supporting evidence from the USA

The thesis that before the war, the production of sodium nitrite was not advanced enough for its application in the meat industry (resulting in high prices and low availability) is confirmed when we consider the situation in the USA.

The first US plant for the fixation of atmospheric nitrogen was build in 1917 by the American Nitrogen Products Company at Le Grande, Washington.  It could produce about one ton of nitrogen per day.  In 1927 it was destroyed by a fire and was never rebuild. (Ernst, FA, 1928: 14)

An article in the Cincinnati Enquirer of 27 September 1923 reports that as a result of cheap German imports of sodium nitrite following the war, the American Nitrogen Products Company was forced to close its doors four years before the factory burned down.  The imports referred to, was as a result of Germany selling their enormous stockpiles of sodium nitrite at “below market prices” and not directly linked to a lower production price in Germany, even though this was probably the case in any event. ( The Cincinnati Enquirer ( Cincinnati, Ohio), 27 September 1923. Page 14.)

The Vienna University document indicate that the fast curing of sodium nitrite was recognised and the ban was lifted when the war ended.  It was this fact that Griffith picks up on in their literature.

This is how it happened that sodium nitrite replaced saltpeter as curing salt.

Conclusion

The ban on the use of saltpeter for non military uses by Walther Rathenau is the likely spark that caused butchers to look at alternative curing systems.  A known alternative was sodium nitrite.  Despite a similar ban on the use of nitrite, later imposed for concerns over the safety of nitrite in meat and because sodium nitrite was also used to produce explosives,  it was available in such large quantities around Germany that it was possible to defy the ban. 

The likely consequence of the developments surrounding the production of atmospheric nitrogen is that sodium nitrite was being produced at prices that was previously not possible.  These prices, combined with the volume of sodium nitrite now available made it a viable proposition to replace saltpeter in meat curing and to remain the curing brine of choice, following the war.

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Notes

(1) “The red color of fresh lean meat, such as beef, pork, and mutton, is due to the presence of oxyhemoglobin, a part of which is one of the constituents of the blood remaining in the tissues, while the remainder is a normal constituent of the muscles. When fresh meat is cooked or is cured by sodium chloride, the red color changes to brown, owing to the breaking down of the oxyhemoglobin into the two constituents, hematin, the coloring group, and the protein, globin.

On the other hand, when fresh meat is cured by means of a mixture of sodium chloride and a small proportion of potassium nitrate, or saltpeter, either as a dry mixture or in the form of a pickle, the red color of the fresh meat is not destroyed during the curing process, the finished product having practically the same color as the fresh meat. Neither is the red color destroyed on cooking, but rather is intensified.” (Hoagland, Ralph.  1914)

(2)   The first export of salitre (sodium nitrate) was authorised by the Chilean government in March 1830 and went to the USA, France, and to Liverpool.  It is the latter shipment which failed and was thrown overboard.  Different sources give different reasons for the action.  One, that price was not attractive,  another, that the excise duties were to high, and a third that the Port captain did not allow the boat to come in because it was carrying a dangerous load.  A few farmers in Glasgow received a few bags.  They used it as fertalizer and reported a three fold increase in crop yield.    (Wisniak, J, et al.  2001:  437)

(3)  Steve Hubbard, Vice President, Global Marketing and Innovation at Griffith Laboratories Worldwide, Inc. graciously provided me with much of the information from company documents.

(4)  Crown Mills was bought out by Bidvest and became Crown National.

(5)   The first War Raw Materials Department (KRA) in Germany was created (KRA) in mid-August 1914,  as suggested by Walther Rathenau.   (Vaupel, E.  2014:  462)  Walter was the son of the founder of AEG and “one of the few German industrialists who realized that governmental direction of the nation’s economic resources would be necessary for victory, Rathenau convinced the government of the need for a War Raw Materials Department in the War Ministry. As its head from August 1914 to the spring of 1915, he ensured the conservation and distribution of raw materials essential to the war effort. He thus played a crucial part in Germany’s efforts to maintain its economic production in the face of the tightening British naval blockade.”

References:

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Brown, Howard Dexter et al.  1946. Frozen Foods: Processing and Handling

Butler, A. R. and Feelisch, M.  New Drugs and Technologies.  Therapeutic Uses of Inorganic Nitrite and Nitrate From the Past to the Future.  From:  http://circ.ahajournals.org/content/117/16/2151.full

Determination of nitrite in meat products.   University of Vienna, Department of Analytical Chemistry, Food Analytical Internship for nutritionists.

Ernst, FA.  1928.  Fixation of Atmospheric Nitrogen.  D van Nostrand, Inc.

Griffith Laboratories Worldwide, Inc. official company documents.

Hoagland, Ralph.  1914.  Coloring matter of raw and cooked salted meats.  United States Department of Agriculture.  National Agricultural Library.  Digital Collections.

Hwei-Shen Lin.  1978.  Effect of packaging conditions, nitrite concentration, sodium erythrobate concentration and length of storage on color and rancidity development of sliced bologna.   Iowa State University Digital Repository @ Iowa State University

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Lang, M. A. and Brubakk, A. O. 2009.  The Haldane Effect.   The American Academy of Underwater Sciences 28th Symposium.Dauphin Island

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Nitrogen.  University Science Books, ©2011

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Van Cortlandt, P, et al.  1776.  Essays upon the making of salt-petre and gun-powder.  Published by order of the Committee of Safety of the colony of New-York.

Vaupel, E.  2014.  Die chemische Industrie im Ersten Weltkrieg
Krieg der Chemiker. Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

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Click to access freebies_SodiumNitriteFactSheet.pdf

http://www.princeton.edu/~achaney/tmve/wiki100k/docs/Haber_process.html

http://www.britannica.com/EBchecked/topic/491966/Walther-Rathenau

en.wikipedia.org/wiki/Nitroglycerin

http://en.wikipedia.org/wiki/Amyl_nitrite

http://en.wikipedia.org/wiki/Amyl_nitrite

Images:

Picture 1:  Smoker trolly with pork belly taken by Eben

Picture 2:  Curing salt taken by Eben

Picture 3:  Atacama Desert.  Photograph by  Dario Lopez-Mills/AP.  Source:  http://www.theguardian.com/science/the-h-word/2014/jun/02/caliche-great-war-first-world-war-conflict-mineral

Picture 4:  World War One:  http://www.excaliburunit.org.uk/#/world-war-1/4580632440

Picture 5:  US troops returning from World War One.  http://www.ww1medals.net/WW1-US-Victory-medals.htm

Picture 6:  Amyl nitrite.  http://en.wikipedia.org/wiki/Amyl_nitrite