Culinary History (Part 37): Tin Cans
Nicolas Appert (1749-1841) was a French brewer who worked first as a steward, and then (during the Napoléonic era) as a confectioner. He was cheerful, bald, and had very thick black eyebrows. His sweet shop was on the rue des Lombards in Paris, and although he knew how to preserve & candy many fruits in sugar, he wasn't happy with this method, feeling that there should be a more “natural” way of doing it. None of the preservation methods were right. Drying took away the food's texture; salt made it “acerbic” (sour/bitter); sugar covered up its true flavour.
Nicolas Appert (1841).
The French Revolutionary Wars lasted from 1792-1802 (a result of the French Revolution). In 1795, France was at war with Britain, and they wanted a better way of feeding their troops. Napoléon offered a prize of 12,000 francs to whoever could come up with a better method of food preservation.
Appert experimented with perserving fruits, vegetables, and meat stews in champagne bottles, which he heated in baths of hot water. The champagne bottles were replaced with wider-necked bottles, and he eventually felt confident enough to send a few botttles to the French Navy. They were pleased – the French Navy Minister remarked that the beans and peas had “all the freshness and flavour of freshly-picked vegetables”. The Courier de L'Europe said that “M. Appert has found a way to fix the seasons.” He received the 12,000 franc prize.
Appert canning jar.
In 1810, Appert published a book explaining his method. While he preserved exotic foods in his corked bottles (such as apricots, artichokes, asparagus, chestnuts, grape must, newly-laid eggs, redcurrants, truffles, young partridges, and the soup of julienned vegetables), the basic process could be used for pretty much anything, and still is today.
But Appert gave up the chance of patenting his invention by accepting the prize. A few months after his book came out, Peter Durant (an English broker) rushed out a patent for a food preservation method that was very similar to Appert's. It was bought by Bryan Donkin (an engineer) for £1,000.
In 1813, Donkin opened a factory called the “Preservatory” in Bermondsey, with his business partners Mr. Gamble and Mr. Hall. The Preservatory produced foods preserved with Appert's methods, heating the containers in boiling watter for up to 6hrs. They switched the glass bottles for tin-coated iron cans (tin cans) because glass was too fragile.
But there were problems at the start. In 1852, thousands of cans of meat for the British Navy were inspected and found to be disgusting, “their contents being masses of putrefecation”. It was thought that “air has penetrated into the canister, or was not originally entirely exhausted,” but this was not the reason. With Pasteur, it was found that there is a class of microbes that can live without air, and need to be killed through heating. The original cans were about 1-2kg (today, they're about 125-800g), and the navy cans were about 5kg, but the length of heating time hadn't been increased for them.
By the 1870's, canned food quality had increased greatly, and it was being sold internationally. A person in Britain could eat Fray Bentos corned beef from Uruguay; someone in China could eat tinned ham from Bermondsey. One canning historian noted that an American family could now pick from “a kitchen garden where all good things grow”.
However, this wasn't quite true, because canning makes some foods taste a bit weird. Spinach is sludgy and metallic. Pineapple and peaches are fine, but raspberries turn to mush.
Cans are used more for drinks than food these days. Globally, about 75 billion units of canned food are sold, as opposed to 320 billion units of canned drinks.
The Can Opener
The first can opener wasn't invented until 50yrs after Appert's invention. Until the 1860's, cans came with the instruction “cut round the top near the outer edge with a chisel and hammer”.
The first can opener was invented by Robert Yeates (a British maker of surgical instruments & cutler) in 1855. It was a claw-like lever attached to a wooden handle: you gouged the lever into the top of the can, and then forcefully cut around it, leaving a jagged edge. It was very difficult to use.
Yeates can opener.
Many strange designs followed. The Warner (used during the American Civil War) had a sharp sickle on the end, which was rather dangerous. In 1868, cans with keys to roll a strip of the top metal off were produced: these worked well for sardine cans, but not for the normal cylindrical tins, because it only opened a part of the lid. Electric openers appeared in the 1930's, but they just made the job more complicated.
A drawing from Ezra Warner’s patent.
The side-opening can opener we have today was invented in the 1980's. It has two wheels which work together (one rotates, the other serrates): they remove the lid in one piece without leaving a sharp/jagged edge. Nowadays, the food industry is moving towards self-opening cans.