CANNING

Canning was a process for preserving food (vegetables, fruits, meats, and fish) by heating and sealing it in airtight containers. The method was developed by French candy-maker Nicolas-Francois Appert (c. 1750–1841) in 1809, though he did not understand why the process worked. Some fifty years later, the pioneering French chemist and microbiologist Louis Pasteur (1822–1895) explained that heating was necessary to the canning process since it killed bacteria (microorganisms) that would otherwise spoil the food.

Canning was introduced to the U.S. consumer market in stages. In 1821 the William Underwood Company began a canning operation in Boston, Massachusetts. Oyster canning began in Baltimore, Maryland in the 1840s. In 1853 U.S. inventor Gail Borden (1801–1874) developed a way to condense and preserve milk in a can and he founded the Borden Company four years later. In 1858 U.S. inventor John Landis Mason (1832–1902) developed a glass jar and lid suited to home-canning.

Early commercial canning methods in the United States did not ensure a safe product; as such, many female consumers avoided canned convenience foods. Nevertheless, the canning industry grew rapidly, due in part to the male market—cowboys in particular. Between 1860 and 1870 the U.S. canning industry increased output from five million to thirty million cans.

Convenience and long shelf life of canned foods helped them to catch on even though the canning process changed food flavor, color, and texture. Improvements in the manufacturing process during the 1870s helped eliminate the chance that cans would burst. By the end of the 1800s a wide variety of canned foods were available at increasingly lower prices and were common in the urban diet. Companies such as Franco-American advertised in women's magazines, promoting their "delicacies in tins." An outbreak of botulism in the 1920s prompted the U.S. canning industry to make further improvements to its preservation processes, but consumer demand for canned products persisted.

See also: Borden

canning The process of preserving food by sterilization and cooking in a sealed metal can, which destroys bacteria and protects from recontamination. If foods are sterilized and cooked in glass jars which are then closed with hermetically sealed lids, the process is known as bottling. Canned foods are sometimes known as tinned foods, because the cans were made using tin‐plated steel. More commonly now they are made of lacquered steel or aluminium. In aseptic canning, foods are pre‐sterilized at a very high temperature (150–175 °C) for a few seconds, and then sealed into cans under sterile (aseptic) conditions. The flavour, colour, and retention of vitamins are superior with this short‐time, high‐temperature process than with conventional canning.