Food safety No. 1 priority for home canners
A lot of home canners rely on their old favorite cookbooks for classic recipes like bread and butter pickles or blackberry jam. But even a traditional art such as canning can benefit from modern science.
“The last comprehensive research of food preservation and safety done was in the 1980s and early ‘90s by the USDA and it did result in major changes. Modifications and corrections were completed in 1993. So home canners using recipes or books published prior to 1988 should replace them with those preferably published 1994 or later,” said Carol Hampton, University of Idaho Extension educator in Boundary County.
“What may have been considered safe is no longer acceptable today,” said Latah County Extension office manager Rachel Rausch. “Just one small example is that tomatoes used to be more acidic than the improved varieties are today, therefore it is recommended to add acid in the form of lemon juice or citric acid to the jars for safety. Older recipes often do not mention it.”
Processing times are often longer now than old recipes suggest. Sealing wax or paraffin is not acceptable for sealing jams and jellies, and the old wire bale and rubber ring type canning jars should be for decoration only.
The risks are too great to flaunt: The main danger of improperly canned foods (even if they are sealed correctly) is botulism, which grows in the absence of oxygen and is fatal even in very small amounts. But canning things properly is easy, so don’t let safety issues deter you. Just use reliable recipes and information and follow directions exactly.
What home canners should know in general is that only acid foods such as fruits, pickles, jams, jellies and tomato products can be canned safely in an water-bath canner; low-acid foods such as vegetables, meats, and seafood need to be canned in a pressure canner, which can raise temperatures high enough to kill any harmful bacteria.
Pressure canners should therefore be checked for accuracy, as a gauge that is off by a pound or two can mean the difference between safely canned foods and deadly ones.
Extension agents sometimes offer pressure canner checks; check with your local extension office to find out if they offer this service.
Many publications on canning are available free through extension offices, and they have extensive information on freezing, drying and pickling as well.
If you have an old recipe you’d like to continue using and just can’t find a newer equivalent for it, or if you come across a recipe for a special item you’d like to try from the Internet, an Extension Food Safety Specialist, like Sandy McCurdy at the University of Idaho in Moscow, may be able to help modify it to meet safety standards.