Published on Wednesday, 30 November -0001 00:00
By Deb Botzek-Linn,
U of M Extension
Are you planning to can green beans, carrots or beets? If so, know that safe home-canned vegetables require processing in a pressure canner.
Low-acid vegetables and meats contain too little acidity to prevent the growth of Clostridium botulinum bacteria. Botulism is a deadly form of food poisoning. It is most commonly found in improperly processed home-canned vegetables, such as green beans, carrots, beets, and mushrooms, as well as other low-acid foods canned at home, including soups, meats, fish and poultry. Because these bacteria grow only in the absence of air, they are harmless on fresh foods.
The spores of Clostridium botulinum can only be destroyed by canning the food at a temperature of 240¼ F or above for a specific period of time. Since this temperature is above the boiling point of water, it can only be reached in a pressure canner. If canned food isn't processed properly, spores of the bacteria aren't killed.
Acid foods, such as fruits, pickled products, sauerkraut, jams and jellies contain enough acidity to block the growth of botulism bacteria and can safely be processed in a water bath canner.
For pressure canning directions and recommended processing times visit the University of Minnesota Extension website at www.extension.umn.edu, and search food preservation. It is critical to use up-to-date research-tested methods when home canning.
Freezing, pickling, or drying are safe and tasty alternative methods of preserving low-acid vegetables if you do not have a pressure canner.