How Canning Was Invented, and How It Changed the Way We Eat

This week I’m talking through five of the greatest breakthroughs in food science, from fermentation to today’s topic: canning.

Because seriously, when was the last time you considered Louis Pasteur, or how canned food was discovered? It’s been a while. These days we’re preoccupied by health fads, gluten-free eating, and vegan alternatives. These concerns might seem overtly disrespectful to the very chefs, chemists, and creators who created the world we eat in, but I would disagree.

I would argue that these very comforts are the perfect tribute.

“Pasteurized milk dramatically reduced the number of infant deaths, which was about 25% of children prior to pasteurization being adopted,” Guy Crosby, Ph.D.; CFS, Science Editor, America’s Test Kitchen; and adjunct associate professor, Harvard T. H. Chan School of Public Health, told me.

But before we dive into the genius of Louis Pasteur or any of the other scientific marvels I’m covering this week, let’s start with food preservation.

Conventional canning as we know it today began with Nicolas Appert, the original Food in Jars guy. A Parisian confectioner and chef, Nicolas began experimenting with preservation during the late 1700s, and he successfully preserved foodstuffs, such as soups, vegetables, juices, and even dairy, more or less. He believed it was the presence of air that led to spoilage, and many of his early experiments were dedicated to removing that element.

He was wrong, but he wasn’t alone in this way of thinking. In the early 1700s, cooked meats were preserved over short periods of time by covering them with a layer of fat, also to protect them from the evils of air, notes Crosby.

But it was Napoleon and the French government that really changed everything. Hoping to find a more effective way to feed his troops, a prize of 12,000 francs was offered to anyone who could devise such a means. Continuing with his experiments, Appert discovered that it was heat (not air) that kept pesky spoilage (caused by microbes, although he didn’t know this) at bay. This was even though the official scientific discovery of those microbes in relation to food spoilage came some 50 years later. (Thank you, Pasteur!) But Appert was correct, even if he didn’t know entirely why.

Appert’s process involved placing food inside glass jars, that were then corked, much like wine, and sealed off with a wax seal. The jars were wrapped in canvas and then boiled. He submitted his invention to the French government and was announced the winner in January of 1810, some 15 years after he first began experimenting. That same year Appert published The Art of Preserving Animal and Vegetable Substances, the first cookbook of its kind on modern food preservation.

“In 1812 the Englishman Brian Donkin substituted unbreakable tin for the glass,” Crosby explained to me. “And the tin can industry was born when Donkin built his first canning factory. Gail Borden was the first to adapt this technology in the United States with the production of canned sweetened condensed milk.”

Initially, this process was very slow and labor-intensive, as cans were handmade, and took up to six hours to cook. This meant canned food was too expensive for ordinary people. Plus, the can opener wasn’t invented for another 40 years, so those cans were a pain to open anyway.

While today there are concerns over salt content and toxins, such as bisphenol A, when it comes to canned food, it is entirely safe.

How safe? In 1974, food samples were taken from cans found on a steamboat which sank nearly 100 years prior, and found completely safe to eat. Of course, you wouldn’t want to eat it. It looked horrible, smelled worse, and was void of any vitamin content. But you could!

So that is why we designated canning as one of the five major food science breakthroughs we’re looking at this week. Without it, the world of food would be a very different place.