August 2009

Since fatal poisoning by botulism is possible from home canning, we often pass on the advice of experts on how to safety preserve those homegrown fruits and vegetables.

Sometimes the home canning experts tell consumers what to do, but do not explain why.   That’s why we like the approach taken by Kathleen Riggs, who is the Utah State University Extension Family and Consumer Sciences Agent for the Bee Hive State’s Iron County.

Take her advice on canned quick breads, for example. She says:

Although no cases of botulism have been identified as being caused specifically by a home canned quick bread, the potential is there. The product meets all the criteria for the organism to grow.

Fact: The organism C. botulinum itself is harmless; however, when conditions are right, it can form an extremely potent toxin. Three factors determine if C. botulinum will grow or not: a nonacid pH, adequate moisture and an airless environment. Canned breads meet all these requirements.

Normally these products are not being held under vacuum and therefore botulism is not a concern. However, sealing the bread in a jar provides he necessary airless condition.

Ms. Riggs writes about other “common practices that are not safe” for eggs in the shell, canned butter, canned wheat, and canning dried beans.  We found her column in The Spectrum in George, Utah.  More of her work can be found at Utah State University.