Safe Home Canning

The canner must appreciate the need to prevent contamination. Otherwise, those who eat the food later may become gravely ill from food poisoning. There are several important precautions canners must take to reduce the risk of food poisoning.

Heat and acid are the two factors to consider for safe canning. Acidic foods such as plums or rhubarb resist bacteria, and require only a boiling water bath method of home canning. Less acidic foods must be canned at higher temperatures, using a pressure canner. Examples of low acid foods include most vegetables, meat and seafood.

Bacterial Food Poisoning

The air we breathe, as well as all foods in their natural state, contain microorganisms such as molds, yeast, bacteria and enzymes. Food spoils when the growth of these microorganisms is not controlled.

There are basically two types of bacterial food poisoning.

Food-borne infection:
- The bacteria are present in the food. After the food is eaten, the bacteria multiply in the digestive system and cause illness.
Food intoxication:
- The bacteria multiply in the food. As they do, they make poisons called toxins. When the contaminated food is eaten, it is not the bacteria but the toxins that cause illness.

Improper canning can result in botulism, which is a type of food intoxication. The bacteria, Clostridium botulism, are found everywhere in the soil and in the water. The bacteria and its spores are harmless. They live in the soil for years. We eat them on raw fruits and vegetables with no ill effects.

Botulism bacteria spores grow in the absence of air.

They produce a toxin, which causes illness and sometimes death when swallowed. Since home-canned foods are stored in airtight containers, they must be prepared and processed properly to prevent the growth of toxins.

Understanding the facts about botulism food poisoning is important because the toxin can be fatal. It is difficult to detect. It is common for botulism-intoxicated food to appear normal.

Sometimes cans or jars contaminated with botulism will bulge or smell bad. Because high temperatures destroy the botulism toxin, persons who eat home-canned foods should consider boiling the food for 10 minutes before eating to ensure safety. Never taste a food. The rule is, when in doubt, throw it out.

Home Canning Essentials for All Foods

Use only top-quality ingredients. Preserve fruits and vegetables at their peak of ripeness. Never use immature or overmature food.
Use heat to process all home-canned foods:
- high acid foods in a boiling water canner; and
- low acid foods in a pressure canner.
Use only tested canning recipes.
Use containers specifically designed for home canning. Do not use coffee, salad dressing, or other jars.
Follow manufacturer's directions regarding preparation of containers.
Cleanliness cannot be overstressed. All work surfaces must be kept clean during all stages of the canning process. The food being preserved must be rinsed clean. All containers and lids must be sterilized.

If you follow these basic principles for home canning, you can safely enjoy your harvest all year long.

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