Pressure Canner Testing

Problem:
Botulism spores are resistant to heat and thrive in a moist, oxygen-free environment. As botulism spores reproduce, they generate a poison that one teaspoon-worth is sufficient to kill 100,000 people. Improper home canning creates the perfect environment in which to grow the botulism toxin. Because food contaminated by botulism may very well look and smell normal, there is often no warning. That is why home canning must be done properly with extreme care; any short cuts you take could be deadly.

To help prevent botulism from occurring, ISUE Nutrition and Health Field Specialists offer information on safe canning procedures and testing of home canner gauges. It's very important to operate the canners at the right temperature which is indicated by pressure gauges. Iowa State University recommends testing dial pressure gauges yearly for accuracy. Correctly calibrated pressure canners are able to reach 240 degrees--the temperature needed to destroy the botulism-causing spore.

Response:
I tested canner gauges in Jones, Jackson, Clinton, and Linn. These dates were promoted by newspaper articles, fliers, radio interviews, etc. The media coverage increased participation. I dovetailed a trip to Jackson County by having my monthly KMAQ interview the morning I did canner testing in Jackson County. This increased the number tested. Many Jackson County residents that brought their testers in said, they had heard me on the radio. The same thing happened in Linn County when I talked about testing pressure canners on the KCRG Noon News. I always take an informal tally of what people are canning and most of the canners are being used for beef or deer. I have the current directions and recommendations for canning beef (and deer) available for people to pick up.
 
Impact:
In 2003, I tested 34 pressure canner gauges. Eight or 24% needed replacement. In 2004, I tested 26 pressure canner gauges so far. Ten or 38% of the gauges should be replaced. In 2005, so far I have tested 21 pressure canner gauges. Seven gauges were recommended to be replaced or 33%.
 
Besides testing the accuracy of the canning gauges, testing gives me a chance to visit one on one with home canners. In one county a young mother with 4 young children brought her grandmother's canner in to be tested. It was a very old model with a gasket and it was sealed by metal on metal. She had no instruction book as to how to use and was leery of using it. She had several large gardens and wanted to can to stretch her food dollars and have food for her family. She had been getting food preservation instructions from her friend. Her friend did not use tested recipes but felt recipes she cooked she could then can. The friend had made chicken noodle soup last year but most of the jars spoiled. This homemaker wanted to learn how to can correctly. We visited about correct procedures and she picked up ISU directions. Her canner needed a new gauge but she decided if she had to buy a new gauge she would get a new canner that she would feel more comfortable with.
 
In another county a homemaker brought her mother-in-law's canner in. The homemaker canned a lot of tomatoes but always processed by the open kettle method.  We talked about the cons of open kettle canning and she said she would think about changing. Several other canner owners had not changed to processing at 11 pounds pressure versus 10 pounds. Although the numbers seem to be declining, it is important that novice canners learn the correct procedures.

Contact:
Susan Uthoff
Nutrition and Health Field Specialist
3279 7th Ave Suite 140
Marion IA 52302-7849
319-377-9839
Fax 319-377-0475
Email x1uthoff@iastate.edu