Old-fashioned canning methods are unsafe

An important announcement about home canning of green beans from the National Center for Home Food Preservation at the University of Georgia:

“People who are still canning green beans at home using the boiling water canner instead of a tested pressure canning process are risking food loss and even worse, possible death or serious poisoning. We are receiving phone calls from people canning dozens and dozens of jars of green beans in boiling water and then losing all that work and food due to spoilage. Beans canned this way looked fine coming out of the canner, but are now turning cloudy and jars are popping open, even sometimes with force. These beans are definitely spoiling from being underprocessed. But it could be worse: even if the jars still look good, it is possible that they contain botulism toxin from this unsafe canning practice.”

Jars of improperly canned vegetables and meats can contain the deadly botulism toxin without showing signs of spoilage such as being seen in the reports mentioned above. Those that do show signs of spoilage could also contain botulism toxin because they are showing other signs of underprocessing.

Battling botulism

Spores of Clostridium botulinum bacteria, as found naturally in soils, are very, very heat resistant. It takes the higher temperatures reached in pressure canning (240 degrees and above) to kill the spores. Even hours in the boiling water canner (at boiling temperatures of 212 degrees) will not kill them if they are inside your jars of beans. Left alive after canning, they will eventually germinate into actively growing bacterial cells that will produce a deadly human toxin. The bacteria are anaerobic, which means they thrive in the non-oxygen conditions inside closed jars of improperly canned low-acid foods (such as vegetables and meats) sitting at room temperature, so they must be killed during the pressure canning process for safe storage.

Current canning guidelines

You can find the USDA-recommended procedures for canning green beans at home here: http://www.uga.edu/nchfp/how/can_04/beans_snap_italian.html

The list of canning processes for other vegetables is found at this menu:

http://www.uga.edu/nchfp/how/can4_vegetable.html

and those for tomato and tomato products here:

http://www.uga.edu/nchfp/how/can3_tomato.html

You can read more about botulism and ensuring safe home canned foods here: http://www.uga.edu/nchfp/how/general/ensuring_safe_canned_foods.html

and principles about safe canning at home here: http://www.uga.edu/nchfp/how/general.html

Be safe with up-to-date home canning

Please be safe when canning foods for you and your family! Knowledge and recommendations change over time with new scientific developments. You  must use up-to-date recommendations and methods and not just rely on practices of past generations.

For more food preservation information from K-State Research and Extension, see http://www.rrc.ksu.edu/DesktopDefault.aspx?tabid=18 or call me at the Finney County Extension Office, 620-272-3670.

“Knowledge for Life” provided by the Finney County Extension Office and K-State Research and Extension.

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