Ricky Pratt, age 10, of Salt Lake City, Utah, for his question:
WHEN WAS FOOD FIRST PUT INTO CANS?
Millions of people preserve fresh food so that it can be stored and eaten later. They use the process of home canning. Fruit and vegetables, gathered from the fields or markets when they are in season and plentiful, can be canned without the loss of food value or flavor and enjoyed later when fresh items are either expensive or not available.
Home canning uses a process which destroys the tiny microorganisms that cause food to spoil. Basically, it's the same method used by commercial canners.
Yeast, molds and bacteria live on food as well as in the air, water and earth. In canning, jars or cans are heated in a way to destroy the organisms. When the containers are sealed, new organisms are kept away from the food.
In the late 1700s Napoleon I of France offered a large prize for an easy, satisfactory way of preserving food. It disturbed him that large amounts of fresh food would spoil before it could be used.
A French candymaker by the name of Nicholas Appert was one of the contestants in Napoleon's contest. He experimented for more than 10 years and finally decided that air caused food to spoil. He knew that if he could keep air away from the food, it would stay edible for a long time.
Appert came up with a way of sealing food in glass containers.. At the same time in England a man named Peter Durand was working on the same theory but was using metal containers. He called them canisters, an English word used for coffee and tea containers. Soon after, the food preserving method was perfected and the name of the container was shortened to can.
By the mid 1800s canning became widespread, although much of food put into jars and cans would still spoil. About 1850 Louis Pasteur in France discovered that bacteria caused most of the spoilage, and he discovered that heating a closed container of food would kill all bacteria and keep others from getting in. Pasteur's finding speeded the progress of canning and led to many new methods of making commercial and home canning better and easier.
In 1858 the Mason jar was invented by John Mason. The top of his jar had a threaded section which permitted a metal cap to be screwed on easily.
Mason's new jar also had a rubber ring between the cap and the jar which served as a gasket to keep out air. The Mason jar is one of home canning's most useful items today.
A man named Alexander Kerr perfected his "Economy Lid'' in 1902 which had a sealing gasket of rubber attached to the lid. In 1914 a two piece Economy Lid which included a screw top was invented for vacuum sealing jars.