Napoleon Bonaparte’s need to keep his army rationed that prompted the invention
of the tin can for food storage. His empire building plans required a huge army
and navy, that were distributed across the world. How to keep them adequately
fed when so far from home or food supplies was an ongoing challenge.
‘Necessity is the mother of
The traditional methods of pickling, smoking, drying and salting proved inadequate when it came to transporting food for a long time, over a great distance. A substantial money prize was offered for anyone who could come up with a better way to keep food fresher for longer.
Preserving food in champagne
Perhaps unsurprisingly, it was a French chef who carried off the prize, when he identified a revolutionary means of keeping food preserved. Nicolas Appert discovered that food packed in champagne bottles and completely sealed remained well preserved. From champagne bottles he progressed to more practical glass containers and successfully preserved vegetables, fruit, meat, fish and even dairy products for the French navy to trial. His next move was filling tin cans with meat and soldering them closed. After 15 years of trial and error, Appert pocketed the 12,000 francs prize.
at this point in history, no one understood why food preserved in this way did
not spoil. Louis Pasteur did not discover why sterilization prevents germ
growth until half a century later. It was also another 30 years before tin
openers were invented. The early tins had to be chiselled open or even stabbed
open with a soldier’s bayonet!
Appert’s discovery did not make his fortune, as he died in poverty, it had changed
food production forever. A British merchant called Peter Durand was granted the
first patent for preserving food in unbreakable tin cans in 1810 (by ‘mad’ King
George III). England’s first commercial canning factory was set up in London three
years later. Further wars and exploration throughout the 1800s encouraged the
popularity and growth of canned food, with household names like Campbell and
Heinz leading the way.
made all the difference to production of tin cans. The invention of the
pendulum press made it possible to make a can end in a single operation and
50-60 cans could be made in an hour, rather than the earliest painstaking
process. Today, the double seam process used in the manufacture of the majority
of food cans means that 2,000 cans can be sealed in just one minute.
processing does tinned food need?
The secret to successfully canning food is to use the minimum amount of processing required to keep food sterile but make sure it still tastes good and has maximum nutritional value. Canning factories are often located close to the fields or coast to minimise transportation time. This keeps the food at optimum freshness before processing and keeps costs down too.
Some food is heated before it is
canned to take the air out and improve packing efficiency. Some vegetables are
peeled or pitted and have to have stalks taken off before being canned. Seafood
usually has to be boned or shelled although the bones of little fish like
sardines get softened when they are heated. Meat and fish are usually cooked
first and boned and compacted before being canned. Tinned foods are heated
under steam pressure to ensure any microorganisms are destroyed.
Innovation has by no means stood
still in tin can manufacture. In the last 20 years, easy open lids have done
away with the need for a tin opener and now complete meals and snacks are also
readily available out of 100% recyclable steel ‘bowls’. Who knows what the next
tin can innovation will be?