Home canning: Put safety first
Sept. 21, 2019—It's an old-fashioned tradition that has regained wide popularity in recent years. But canning at home is not without its dangers—including a potentially deadly form of food poisoning called botulism.
Big bad botulism
Canned foods seem wholesome. But when improperly prepared, they can harbor Clostridium botulinum. This nasty germ can produce a poison that's odorless and tasteless but very dangerous. The toxin can affect nerves and cause paralysis or even death. Botulism is a rare illness, but it doesn't make sense to take chances.
The first thing to know: Heat from a pressure cooker is the only way to protect against botulism when canning most foods. C. botulinum can be very heat-resistant, and its spores can survive for hours in boiling water. If left alive after the canning process, the germ can grow and have deadly consequences.
Keep your canning safe
Here's how you can successfully preserve food—and your health:
- It's all in the technique. A comprehensive guide can help you take the right steps at the right time. The National Center for Home Food Preservation offers a series of helpful resources.
- Use the right equipment. Pressure canning, which heats jars to at least 240 degrees, is the only safe method for preserving low-acid foods. These foods don't contain enough acid to prevent the growth of C. botulinum. Low-acid foods include asparagus, green beans, beets, corn, potatoes, meats and fish. Almost every vegetable is low-acid.
- When in doubt, throw it out! If you think there's a chance that food wasn't canned safely, don't do a taste test. It's not worth the risk. Throw out any container that is leaking, swollen or damaged or that spurts liquid when opened. If the food is moldy or discolored or smells bad, pitch it.
A little care can help your family enjoy preserved foods for months to come. Want to be extra safe? Learn more about other foodborne illnesses—and how to avoid them.