Chapter 12.04: The Saltpeter letter

Introduction to Bacon & the Art of Living

The story of bacon is set in the late 1800s and early 1900s when most of the important developments in bacon took place. The plotline takes place in the 2000s with each character referring to a real person and actual events. The theme is a kind of “steampunk” where modern mannerisms, speech, clothes and practices are superimposed on a historical setting.  Modern people interact with old historical figures with all the historical and cultural bias that goes with this.

narrative – the history of bacon

The Saltpeter Letter

June 1891

Dear Children,

The days grow ever more light and joyful as summer approaches. The cornerstone of meat curing is saltpetre and understanding its composition and function in meat is the starting point to unravelling the mysteries of bacon. Curing was thought to be a separate discipline from fermentation such as is used in making salamis and drying, such as is used in biltong. Curing is predicated upon chemical reactions while fermentation is done through bacteria. I will later return to this point and show that curing is also possible through fermentation. In fact, the oldest form of curing was a fermentation reaction. For now, however, lets remain with the simple thought that saltpetre is what cures meat. This reaction, which starts with saltpetre is the overarching and controlling mechanism in bacon production. I am thankful that I educated myself in the latest developments in chemistry. I wrote to you in my last letter about how I reviewed the basic formation of salts with Minelle on the Witels hike. Uncle Jeppe’s classes are far more meaningful to me now that I have context about how these salts are formed and I am thankful that I shared my knowledge with Minette right from the start.

1910 photograph – sent to Schalk LE ROUX by Martinus van Bart Photographer: Unknown

My mind drifts back to Cape Town when I see the Danes going about their business of being Danish! Like saltpetre in bacon, there are principles that make this great nation who they are. Traditionally, their work ethic, their view of the equality of all humans, and their model of cooperation are not just good ideas. It is fundamental to their existence as people. We have similar beliefs that make us who we are as an emerging nation. Mental pictures such as religion and the concept of the Boer in Africa shaped our society. I remember the last church service at the Groote Kerk in Cape Town before I left on my grand quest.

It is in the same church where my mom and dad were married and where I was christened as a baby. As staunch Calvinists, much of life revolved around church and the Groote Kerk was my second home.

It was the first Christian place of worship in South Africa. The oldest church structure on this piece of land dates to 1678, 26 years after the Dutch landed to set up their refreshment station. The current building was built by the German architect, Herman Schuette in 1841. Much of the old church, including the steeple, was retained in Schuette’s new design. It is situated right next to parliament. The last Sunday before I left for Europe, my kleinneef (my mother’s cousin) preached.

He is a true gentleman with a large pastoral heart. His theology is progressive, and his faith is sincere. My mom and dad are close to Oom Giel and his brother, Oom Sybrand. They are my mom’s cousins.

That particular morning his text was Ephesians 5. I remember hearing the horse carts rattling by in the street outside the church down Adderly street. As always, there was energy in the air as people arrived. The Graaff brothers and sister sat in their own allocated seating as did the other families. Each had its own seating reserved for them. The men hung their hats on the racks provided for them.

Oom Giel’s thesis was “Live as people of the light.” Here, at the Groote Kerk, the people who started the Cape Colony worshipped and received their spiritual direction. Oom Giel stressed that we received the light, but he was humble about what that meant. As a theologian, he was ahead of his time. “A day will come when we realise that the church does not have all the answers. One day the church will no longer be able to scare non-believers into faith with the threat of hell. The light we receive is that we are in God’s hands. It’s a way of life.”

Deep-seated Calvinism shaped the colony. From the straight roads and square corners on neat houses to straight orchards. They believed God was in the first place viewing life as a geometer and this shaped everything they did. The Groote Kerk is the spiritual spring of the Colony.

Adderly Street

The Groote Kerk is at the top of Adderley Street.  This was the scene outside when Oom Giel preached.  Photo by Michael Fortune.

It was not only an obsession with geometry that bewitched those who drank from this well with a misplaced superiority complex over all of God’s world, but good was also distilled from these waters. A friend from further up in Africa pointed it out to me one day when he visited Cape Town, and I took him around to see the beautiful city. A mindset prevails among its inhabitants that says, “We are here, and we can thrive! We can get many things from Europe, but by golly, we can do it ourselves! What we can do is any time as good as the best we can get from Europe! With discipline and diligence, we approach every task set before us! In straight lines!”  This is exactly the reason I am in Denmark. An inherent belief that whatever the Europeans can do, we can do better! First, I had to learn from my ancestors!

Apart from this, people from southern Africa mind their own business and desire a quiet life. We want to live in light of our gospel. That is how I remember Oom Jacobus Combrinck. How he cut his meat and wrapped it for customers; cured the bacon; grew his spices in his enormous garden at his home in Woodstock; these are all outworkings of his fundamental view of life.

As Oom Giel led us in reciting the Apostolic Creed, I wondered how many times through the years it was recited in this Church! The settlers, for all their faults – many of them were bound by this confession and tried to live true to its articles.

Oom Giel broke the bread. It is communion with the body of Christ. And so is the wine, union with the blood of Christ. Our rituals and confessions link us to countless generations. Past and present and from these deeply held beliefs we became. On my last Sunday in Cape Town, I listened to Oom Giel with many of my family and friends attending. It was a special day!

Adderly Street 2

The Groote Kerk is at the top of Adderley Street.  This was the scene outside when Oom Giel preached.  Photo by Michael Fortune.

Now I am learning another gospel in Denmark. The art of curing bacon and the salt we use is saltpetre. That day at the Groote Kerk, Minette was also there. We sat together and shared communion. Today it is Sunday and again, Minette is here with me. 

It is a surprise I never expected! She arrived last weekend and Uncle Jeppe returned from Liverpool during the week. This morning she joined me at his bacon factory.

Uncle Jeppe reminded me of Oom Giel when he leaned forward in his chair pressing down on his desk. Passion for the subject. Authoritative. Uncle Jeppe must have been quite a lady’s man in his day! He made Minette feel very welcome and gave her the grand tour of the factory. At lunchtime, I was already sitting in his office waiting for them.

They walked in while Uncle Jeppe and Minette were laughing at a joke. They do not share the joke with me.  “So, today we go back to a time when saltpetre was still a mysterious compound,” Uncle Jeppe said.  Minette took the seat beside me. Uncle Jeppe walked behind his desk where he took a notebook out of a drawer. He does not sit in his chair but walks around the desk and sits on it facing us. “The story of saltpetre goes back, aeons of time!”

Minette interjected that she still remembers exactly how it is formed. She looked at me when she recounted it. “Nitrogen Dioxide (NO2), formed in the atmosphere when nitrogen reacts with ozone, reacts with raindrops which is water or H2O. The two oxygen atoms of nitrogen dioxide combine with the one from water to form three oxygen atoms bound together. There is now one nitrogen atom bound to three oxygen atoms to give us NO3 or nitrate. There is still one hydrogen atom left and it combines with the nitrate to form nitric acid (HNO3). Nitric acid falls to earth and enters the soil and serves as nutrients for plants.”

Adderly Street 3

The Groote Kerk is at the top of Adderley Street.  This was the scene outside when Oom Giel preached.  Photo by Michael Fortune

“In the ground,” I finished her thought, “it reacts with a salt such as potassium, calcium or sodium to form potassium nitrate, calcium nitrate, or sodium nitrate, which is taken up as plant food.”  I smiled at her.  “You remember well!”

Uncle Jeppe smiled. He almost got lost in that moment. He pulled himself back to reality and opened his notebook. He balanced the open book in his one hand. He is a meticulous note-keeper, something that I learned from him. He keeps notes written in his neat cursive handwriting. One can see that he values every sentence he writes! I now have my own notebook and on Sundays, I review the work we covered each week and I write what I learned or saw in my letters to you guys.

“Saltpeter is one of the magical salts of antiquity. For most of human history, we did not know what saltpetre was,” Jeppe preached. “Saltpetre was used in ancient Asia and in Europe to cool beverages and to ice foods. There are reports dating back to the 1500s about it. Without any doubt, it was known for millennia before it was reported on in writing.” (Reasbeck, M:  4)

“From antiquity, the ancients cured their meat with it and enjoyed its reddening effect, its preserving power and the amazing taste that it gives. The earliest references to it go back to people in Mesopotamia from the Bronze Age who used it in the same way as the Romans. The characteristic flavour it imparts to meat was reported in 1835 (Drs. Keeton, et al; 2009) but there can be little doubt that it was noticed since many thousands of years before the 1800s.”

“The Chinese worked out how to make explosives, using the power of saltpetre. There is even a record of gunpowder being used in India as early as 1300 BCE, probably introduced by the Mongols. (Cressy, David, 2013: 12) People started using it as a fertilizer when overuse of the land required us to replenish the nutrients in the soil.”

“It was widely known from the markets in China, India, the Middle East, North Africa, Europe, and England from where it was traded. It was its use by the military in gunpowder and its pharmaceutical use made it generally available in Europe from the 1700s. This meant its usage as curing agent with salt increased and by 1750 its use was universally found in curing mixes in Europe and England. Most recipe books from that time prescribed it as a curing agent.” (Drs Keeton, et al, 2009)

“Despite its wide use by 1750, people still could not work out if saltpetre occurred naturally or if was it something that had to be made by humans. When they managed to get hold of it, they wondered how to take the impurities out of the salt which gave inconsistent curing results and was no good in gunpowder. People were baffled by its power. Some speculated that it contained the Spiritus Mundi, the ‘nitrous universal spirit’ that could unlock the nature of the universe!”

Groote Kerk 2
The photo of the Groote Kerk was among the first taken in SA, by Piazza Smyth of the Royal Observatory, c. end-1842 to start-1843. Photo and information supplied by Ian Glass.

Jeppe quoted Peter Whitehorne, the Elizabethan theorist who wrote in the 1500s. He said about saltpetre, “I cannot tell how to be resolved, to say what thing properly it is except it seemeth it hath the sovereignty and quality of every element”.

Paracelsus, the founder of toxicology who lived in the late 1400s and early 1500s, said that “saltpetre is a mythical as well as chemical substance with occult as well as material connections.” The people of his day saw “a vital generative principle in saltpetre, ‘a notable mystery which, albeit it be taken from the earth, yet it may lift up our eyes to heaven’” (Cressy, David, 2013:  12)

Jeppe got up and settled in his large office chair. He leaned back as he continued to read. “From the 1400s to the late 1800s we have records of almost every scientist probing and testing it to determine its properties. No doubt, ancient scientists and stone age chemists did the same for many thousands of years and in a way, it is the fascination with enigmatic salts that precipitated the science of chemistry.”

“Saltpeter encompassed the “miraculum mundi”, the “material universalis” through which ‘our very lives and spirits were preserved. Its threefold nature evoked ‘that incomprehensible mystery of … the divine trinity,’ quoting Thomas Timme who wrote in 1605, in his translation of the Paracelsian Joseph Duchesne. “Francis Bacon, Lord Chancellor and Privy Councilor under James I, described saltpetre as the energizing “spirit of the earth.”” (Cressy, David, 2013:  14)

“Robert Boyle, who did experiments trying to understand saltpetre, found it ‘the most catholic of salts, a most puzzling concrete, vegetable, animal, and even mineral, both acid and alkaline, and partly fixed and partly volatile. The knowledge of it may be very conducive to the discovery of several other bodies, and to the improvement of diverse parts of natural philosophy” (Cressy, David, 2013:  14)

I could tell that Minette loved it!  We were both riveted to every word!  When I saw her interest in the subject, I realised that in Minette I not only had a friend and a beautiful friend at that, but I had a partner to explore life with me. She not only loves nature and explores our natural universe, but she also has an amazingly inquisitive mind in all technical matters. 

Tristan, and Lauren, I was completely dumbstruck! On the one hand was the realisation that there are bonds between Minette and me that are stronger than simply friendship. On the other hand, there is the realisation that the salt that I have been using to cure pork for most of my life is one of the greatest salts from antiquity! I used it with my dad and Oupa Eben on the farm every time we cured Kolbroek meat.  Here in Denmark, I work with it every day! 

I was overcome by a feeling of deep respect for this compound that we readily use. Even now that we know saltpetre is a salt attached to an acid in the form of one nitrogen atom and three oxygen atoms (CaNO3), its history is remarkable! I stepped onto a stage where a Shakespearean drama has been acted out and I became part of a grand history. I would never again hold it in my hand and think of it in the same way!  Saltpetre is far more than just its chemical composition! Contained in its essence is the spirit of every man and woman who ever looked at it to unravel its secrets for thousands of years.

Groote Kerk rebuilt ca 1840. The tower and pulpit date from the 18th cent. Supplied by Martin Greshoff.

I recall Oom Giel’s sermon. “Live as people of the light. Be true to your most basic quality.” For millennia, saltpetre mesmerized us long before its essential nature could be explained. Oom Giel’s message was the same. Mesmerize others with your essential Christian character. There should be no need for debate or discussion.

It is late in the Østergaard family home. Andreas, his dad, mom, Minette, and I were discussing Uncle Jeppe’s lessons from today after supper. They told us about a museum dedicated to geology in Copenhagen and they are planning to take us there next weekend where I intend to explore the question of the origins of saltpetre more closely. The question of who were the first people to change the use of saltpetre into an art? Who harnessed its use and who established what is now the collective knowledge of saltpetre into an art?  The art of curing meat. Who were the custodians of its power for millions of years of human history?  I intend to explore this question with the good people from the University next weekend!

Both Minette and I are excited. The house is now quiet with everybody asleep except me, wrapping the day up with my customary letter to you guys. I love you more than life itself and can’t wait to share what we learn from the University next weekend.

Lots of love,



(c) eben van tonder

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Cressy, D.  2013.  Saltpeter.  Oxford University Press.

Cressy, D.  Saltpetre, State Security, and Vexation in Early Modern England.  The Ohio State University

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Shenango Valley News (Greenville, Pensylvania), 26 January 1883

Smith, Edward.  1876. Foods. D. Appleton and Company, New York.

Schaus, R; M.D. 1956.  GRIESS’ NITRITE TEST IN DIAGNOSIS OF URINARY INFECTION,    Journal of the American Medical Association.

Photo credits:

The 1910 photo of the Groote Kerk, from

All other photos by Eben van Tonder