What Are the Differences between Canning and Freezing?

Canning and freezing are two different methods of preserving foods, the difference being in the process in which the foods are preserved for future use. Canning involves the use of canning jars, which are generally stored in a cool, dry place, while foods that are frozen are placed in freezer-safe containers and stored in the freezer. Canning and freezing are both acceptable methods of home food preservation. Canning is a more viable choice since the foods generally have a longer shelf-life and will not spoil during a power outage, while freezing is a preferred choice over canning due to the amount of time and steps involved in the canning process.

Home canning has been a method of food preservation for more than a century. Invented by French inventor Nicolas Appert, canning foods during the early 1800s was a complex process to perfect. Appert’s method of canning was a process of bottling food in glass bottles that were then sealed with corks and sealing wax. Soon after Appert’s invention, Peter Durand developed the method of preserving foods in metal cans.

Canning at home today uses the same method that Appert had invented, as foods are placed in sterilized glass jars and immersed in hot water. Only certain types of foods are able to be preserved using this approach often referred to as water-bath canning. For low-acidic foods such as meats, pressure canning is the recommended method.

Clarence Birdseye has been credited with the invention of quick freezing, the technique in which most foods are preserved at home today. Although the process of freezing foods was used prior to Birdseye’s method, the manner in which he froze foods removed some of the problems that were encountered during older methods. Birdeye’s technique involved “quick” freezing and pre-packaging the foods, which eliminated the problem of ice crystal formation. Freezing foods in the modern kitchen involves placing fresh foods into freezer-safe containers and placing in the freezer. Proper packaging is the key to preventing deterioration of the food’s quality during storage, as damage commonly known as "freezer burn" can occur when the food comes in contact with the air circulating in the freezer.

The choice between canning and freezing often depends upon the type of food to be preserved and how long the food will be stored. Generally, foods such as cooked meats can be stored in the freezer for two to three months, while properly canned meats will keep for two or more years. Canning and freezing also differ in the long-term quality of the foods after preservation. The flavor of foods can deteriorate the longer they are frozen; however, canned foods often retain the same flavors throughout their shelf life.