Don't let canning become a recipe for disaster

Home canning vegetables improperly can lead to the growth of bacteria and their toxins.

Christina Rittenbach
Christina Rittenbach, extension agent, Family and Consumer Sciences division of the North Dakota State University Extension Service in Stutsman County.
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Your garden is producing a bumper crop this year, so you´d like to pickle or can some of that bounty.

Don´t let your experience become a recipe for disaster.

The first step is to use a recipe the U.S. Department of Agriculture has tested and approved. A lot of recipes are available on the web, in old cookbooks and from friends and family. The problem is that most of those recipes haven´t been tested for safety.

Home canning vegetables improperly can lead to the growth of bacteria and their toxins. For example, Clostridium botulinum produces a toxin. If a food containing the toxin is consumed, a potentially deadly form of food-borne illness can result.

Listeria is a type of bacteria that can be found in raw vegetables, milk and meat, soft-ripened cheese, poultry and fermented raw-meat sausage. It grows at refrigerator temperatures and can survive in acidic conditions. That means it could survive and grow in unprocessed refrigerator pickles without the proper level of vinegar. Heat kills Listeria, so proper canning will inactivate this type of bacteria.


Most bacteria are hard to remove from food surfaces, according to experts at the National Center for Home Food Preservation. They say that washing fresh food reduces bacteria levels only slightly, but that peeling root crops, underground stem crops and tomatoes cuts bacteria numbers significantly. Blanching vegetables also helps, but the best bacteria control is using proper canning methods, they say.

Following canning or pickling recipes exactly also is vital. Canning is a science, while cooking is an art. You don’t have a lot of room for creativity when canning. Altering ingredients and proportions can result in a deadly mixture.

Here is some other advice from the experts:

  • Select fresh, firm fruit or vegetables that are free of damage.
  • Measure or weigh ingredients carefully.
  • Use canning or pickling salt because other salt may make the pickling brine cloudy.
  • Use distilled white vinegar or cider vinegar with 5% (50 grain) acidity.
  • Process canned products in a pressure canner or boiling-water canner, depending on the acidity of the food. Foods with enough acid can block bacteria´s growth and destroy them more rapidly when heated.
  • Use standard canning jars and self-sealing lids.
  • Store home-canned products in a cool, dark place.
  • For best quality, use the products within a year.

For more information on safe home canning, check out the North Dakota State University Extension website at or contact Christina Rittenbach, Stutsman County Extension agent, at (701) 252-9030 or

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