HISTORY OF CANNED FOOD

It was during the period of the Napoleonic wars that the Frenchman Nicolas Appert found that food could be preserved against spoilage by first sealing it in an airtight glass jar, and then heating it. After many years of careful trials and experiments, he published a book on his process in 1810, which became a great success in many countries. By this time, Appert had set up his own factory to produce and distribute his preserved foods. The French government was so impressed by his discovery that they gave him an award of 12,000 Francs. Although Appert's method clearly worked, nobody knew exactly why at the time. It wasn't until the end of the 19th century that it was found that bacteria were the cause of food spoilage, and that these were destroyed by heating. Appert's discovery was taken up in England by John Hall, founder of the famous Dartford Iron Works, and his associate Bryan Donkin in 1811. As well as using glass bottles, they developed the use of metal canisters made of tinned iron to store the food, which were of course virtually unbreakable. Thus the world's first `canned' food was made in their new factory set up in Bermondsey, London. Preserved food was naturally of great interest to the Navy, and many samples were sent to seafarers for trial; the new canned foods received high commendation for quality from many sea captains and sailors. At first, however, they were mainly used as emergency rations for the sick, because of their relatively high price. In fact, canned foods remained the preserve of the rich until the latter half of the 19th century. The cost of a 1 lb can of meat in 1813, for example, was about 3 shillings (15p), but this was nearly one-third of the average weekly wage of a labourer. As a good, if rather extreme example of the preservative powers of the canning process, a can of roast veal and gravy dating from Captain Sir Edward Parry's third voyage in search of the North-West Passage in 1824 was opened and examined in 1939. The contents were found to be still wholesome and laboratory tests showed that the meat had been of good quality and that it had retained its nourishing qualities to a high degree for over a century! Each of the early cans were handmade individually, from three pieces of tinned iron: one curved around to form the body, plus top and bottom pieces. A skilled person could make perhaps six cans per hour. This is a far cry from today's modern canmaking lines which are capable of producing more than 1200 cans a minute! The earliest cans were quite heavy, and a hammer and chisel was needed to open them. Nowadays, every home has a can-opener, sometimes even an electric one, and many cans now have an `easy-open' end with a ring-pull.

The can marches on... 

Since its earliest days, enormous progress has been made by the canning industry, with many millions of pounds poured into research and development, and this continues today. The original cans, as we have said, were made of iron sheet that had been dipped into molten tin. Iron was soon replaced by steel, a far superior material that could be rolled out into thin sheets. In the 1930s, electroplating began to replace hot dipping as the way to apply the tin, and today, all `tinplate' for cans is made this way. Modern tinplate consists of a thin sheet of steel covered with a very fine layer of tin to protect the steel from the effects of the environment and to keep it bright and shiny. Tinplate is non-toxic, safe and strong and can be transported, stored and stacked easily, withstanding the knocks that it is likely to receive during its journey to the customer. There are now several different ways to make a can. Most food cans are called `three-piece' because they are made using three separate pieces of tinplate, just as the very first cans were. A rectangular sheet is curled round to form a cylinder, with its edges just overlapping; this is then welded at high speed by a special process to form the can body. The top and bottom ends are stamped out quickly by another machine. The bottom is seamed on first, the cans are filled with the product, and then the top is seamed on. This is followed by the cooking/sterilising process. All of these stages are now highly automated. Another type of can is called `two-piece'. Here, the body and base are formed from a single disc of tinplate that has been punched into the desired shape by one of two methods. There is no side-seam on this can. You will notice that nearly all drinks cans, as well as those for pet food, are of this type. The easy-open end is an invention that has helped to make the can even more popular, especially for drinks, but it is now increasingly being found on food cans as well.

Not forgetting your pet...

In the United Kingdom today, it is estimated that over half the households own a pet, and about £1,000 million is spent every year on pet food, of which about half is spent on canned food for cats and dogs. The invention of canned pet food can be traced back to the 1930s in the United States when a type of canned dog food was produced consisting of meat by-products mixed with cereal grains, then canned and cooked. Today, the pet food market is very large in some countries: no less than 30% of all food cans made in the United Kingdom and Australia are for pet food, and 11% in the USA.

And drinks too...

The idea of putting beer in a can appears to have started in the USA around 1935. Today, the canning of beers and soft drinks is an enormous industry, using high-speed 2-piece can production, can printing, and filling processes. The development of various easy-open ends has helped to popularise this convenient form of drinks packaging. The list of products now packed in `tins' of some kind is of course not confined to food and drink. There are paints, aerosol sprays, polishes, cosmetics, oils, adhesives, and gifts of all kinds........ After 150 years, the `tin can' is now more versatile, attractive, economical, and convenient than ever.


Originally published in http://www.tinplategroup.com/pooled/articles/BF_DOCART/view.asp?Q=BF_DOCART_197927. Edited to be posted by LC.