Home Canning: Keep Your Family Safe!
Elizabeth L. Andress, Ph.D., Professor and Extension Food Safety Specialist, University of Georgia
Home canning—what better way to enjoy the fruits of your labor and save money? National movements to promote home canning are gaining momentum, and people are returning to home canning after years away or starting to can for the first time. In fact, according to one survey, 1 in 5 U.S. households can their own food, and many of those households can vegetables. But if canning is not done safely, your canned food may become contaminated with germs that could make you very sick--or kill you. Protect yourself, your family, and others when you share your home-canned goodies by learning how to can safely.
Be Safe—Botulism Can Be Deadly
Many home canners are not aware of the risk for botulism, a rare but potentially fatal form of food poisoning that has been linked to improperly canned food. The bacteria that cause botulism, Clostridium botulinum, are found in soil and can survive, grow, and produce a toxin (poison) in sealed jars of food. This toxin can affect your nerves, paralyze you, and even cause death. Even taking a small taste of food containing this toxin can be deadly.
Take Care When Canning
The only protection against botulism food poisoning in low acid home canned foods is the heat applied during canning. Using traditional methods that were handed down over generations or using boiling water instead of a pressure cooker can be deadly. Consult The Complete USDA Guide to Home Canning to ensure you are canning safely.
Canning low acid vegetables (like green beans and corn), meats, fish and poultry requires the use of a pressure canner. The safe canning methods available for home canning are all based on pressure canning. Clostridium botulinum can form spores that are very, very heat resistant. Even hours in the boiling water canner will not kill it. Left alive after canning, the germ will grow and produce a deadly toxin.
Clostridium botulinum grows well and can produce toxin inside closed jars of low-acid foods at room temperature, and you can’t always tell by looking. Jars of improperly canned vegetables and meats can contain the deadly botulism toxin without showing signs of spoilage. You can’t taste it or smell it, so you don’t even know it’s there, and it can kill you. The bacteria must be killed during the canning process for safe storage.
Why You Must Use a Pressure Canner
Clostridiun botulinum spores are very hard to destroy at boiling-water temperatures. High acid foods such as fruits and tomatoes can be processed or “canned” in boiling water. In this method jars of food are heated completely covered with boiling water.
But low-acid vegetables and meats must be processed in pressure canners. Jars of food are placed in 2 to 3 inches of water in a pressure canner, which is then heated to a high enough temperature--at least 240 ◦F. This temperature can only be reached in a pressure canner.
Select the Right Pressure Canner
Select a pressure canner made for canning and not just pressure cooking, and select the right size canner. Canners that are too small can lead to under processing or under cooking.
Make sure all parts of your pressure canner are in good condition.
- If your canner has a rubber gasket, make sure it is flexible and soft, not brittle, sticky or cracked.
- Check the openings on any small pipes or ventports to be sure they are clean and clear of any debris.
- If you live at a high altitude, adjust your canning process for safety. Check with your pressure canner manufacturer or click on one of the links below.
- Pressure canners should also have the air vented from them for 10 minutes before you pressurize the canner. Read more about this step and other step-by-step procedures for using pressure canners: Preserving Food: Using Pressure Canners
Follow Up-to-Date Canning Instructions
Canning instructions and equipment have changed over the years. Following up-to-date canning instructions from a reliable source such as USDA or your state Cooperative Extension Service is essential for food safety. You worked hard to grow and harvest your garden bounty. Make sure you preserve it safely.
Check out CDC’s Feature on Home Canning and Botulism
See the USDA home canning procedures at the National Center for Home Food Preservation
Read Botulism Frequently Asked Questions from the Centers for Disease Control and Prevention
If you have other food safety questions feel free to contact us at the Hotline (888-674-6854) or online at AskKaren.gov (FDA)
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