What can cause food spoilage in pressure canned goods?

Causes of Spoilage

Food spoilage in pressure-canned goods can be attributed to several factors. Inadequate processing time is a common issue, where the canning process is not completed within the recommended time frame. This can result in undercooked or under-sterilized food, creating an environment for bacterial growth. For example, if the recommended processing time for green beans is 20 minutes at 10 pounds of pressure, a failure to meet this requirement can lead to spoilage.

Factors Contributing to Spoilage

Low acidity is another factor that can contribute to spoilage. Acidic foods, such as tomatoes and citrus fruits, are less susceptible to spoilage due to their natural acidity. However, non-acidic foods, such as meats and vegetables, require additional acidity to create an environment that inhibits bacterial growth. This can be achieved by adding lemon juice or vinegar to the food before canning. A general rule of thumb is to add 1 tablespoon of lemon juice or vinegar per quart of water.

Contamination and Spoilage

Contaminated equipment is a significant contributor to spoilage. If the canning equipment is not properly cleaned and sanitized, bacteria and other microorganisms can be introduced into the food, leading to spoilage. To prevent contamination, it is essential to clean and sanitize all equipment, including the pressure canner, jars, and utensils, before use. This can be achieved by washing the equipment with soap and water, followed by a sanitizing solution of 1 tablespoon of unscented chlorine bleach per gallon of water.