Purpose of Processing Times

• In canning, processing times have multiple purposes. One purpose is that processing your jars ensures a quality seal. However, the greater purpose is that processing times ensure the safety of your food. These processing times are formulated for each recipe to ensure that the heat of your processing vessel reaches all of the contents of the jars you are processing, and does so for a prescribed amount of time to kill molds, yeasts and bacteria.

Boiling Water Bath Canning

• Boiling water bath canning is used for high acid foods such as jams and jellies, as well as acidified foods such as pickles. In these types of foods, processing times are set to ensure a good seal and kill all present yeast, bacteria and mold. An exception to this is the spores of toxic bacteria clostridium botulinum -- botulism as it is commonly known -- which remain viable. However, they are unable to grow due to low pH, and pose no health threat at this stage. Failure to process high acid foods to their recommended processing time can result in seal failure and mold and bacteria growth.

Pressure Canning

• In pressure canning, failure to comply with recommended processing times has more dire effects, because it can cause the germination of deadly clostridium botulinum spores. Low acid foods such as corn, beans and meats require careful adherence to pressure and processing times to ensure that the spores are killed through the pressure canning process. Botulism most often shows no outward signs in your food, making it nearly impossible to detect in home-canned foods.

Correctly Following Processing Times

• Processing times are unique for each recipe and must be followed closely. Along with processing times, it is important that you follow all associated directions and recipes. Use reliable and tested recipes for canning to ensure that pH levels and processing times are adequate for the type of canning you are doing. If you are canning at 1,000 feet above sea level or greater, adjust your processing time to account for this by using a chart found in any reliable home canning book.