Canned Food

Food which is kept too long decays. The canning process, however, seals the product in a container so that no infection can reach it, and then it is sterilized by heat. No chemical preservatives are necessary, and properly canned food does not deteriorate during the storage.

The principle was discovered in 1809 by a Frenchman called Nicolas Appert. He corked food lightly in wide-neck glass bottles and immersed them in a bath of hot water to drive out the air, and then he hammered the corks down to seal the jars hermetically. Appert’s discovery was rewarded by the French government because better preserved food supplies were needed for Napoleon’s troops on distant campaigns.

By 1814 an English manufacturer had replaced Appert’s glass jars with metal containers and was supplying tinned vegetable soup and meat to the British navy. The next scientific improvement, in 1860, was the result of Louis Pasteur’s work on sterilization through the application of scientifically controlled heat.

Today vegetables, fish, fruit, meet and beer are canned in enormous quantities. Within three generations the eating habits of millions have been revolutionized. Foods that were previously seasonal may now be eaten at any time, and strange food is available far from the countries where it is grown.