Home Canning: Safe Practices

Busting Botulism!

As the growing season comes to an end, it becomes the perfect time to start canning produce. Home canning has become an increasing trend in the last several years. According to the Centers for Disease Control (CDC), one in five households participates in home canning. Of those households, 65 percent of them are canning vegetables. Canning is an excellent way to provide garden produce to your family year-round. However, there are health risks involved if not done properly.  Michigan State University Extension recommends that before you begin canning your produce, you should take some time to review the proper techniques to avoid food borne illness.

Botulism is a rare form of food poisoning that is associated with improper home canning practices. Clostridium botulinum is a type of bacteria that is found naturally in the soil and on produce.  It can grow and multiply in canned foods and create a dangerous toxin – botulism. Specific conditions must occur for the bacteria to grow. The environment must have less than two percent oxygen, include a low-acid, moist food and a have a temperature between 40 and 120 degrees Fahrenheit. Examples of low acid foods include red meat, poultry, seafood, milk and all fresh vegetables, except tomatoes.

Even a small taste of infected food can cause botulism poisoning. Common symptoms of botulism include blurred or double vision, slurred speech, difficulty swallowing, dry mouth, muscle weakness and droopy eyelids. The CDC advises individuals to examine their home canned foods before consuming. You should look out for:

  1. Jars that are bulging, swollen or leaking
  2. Jars that are cracked or look damaged
  3. Jars that spurt liquid or foam upon opening
  4. Foods that may appear to be discolored, moldy or have an unusual odor

If in any instance you are unsure, throw the product out! Do not sample it to determine its safety. 

To avoid botulism, use proper equipment and techniques when canning produce. All low-acid foods should be canned in a pressure canner. Clostridium botulinum is extremely heat resistant and will not be killed by boiling water. The jars of food should be placed in two to three inches of water and then heated to a temperature of at least 240 degrees Fahrenheit in a pressure canner.

If you have questions about canning meats, poultry, vegetables or fish, contact your local MSU Extension office or call 888-MSUE4MI (888-678-3464). Home canning is an excellent way to preserve garden produce. By following the correct techniques you will be able to ensure safe, healthy, garden produce for family and friends throughout the year.

Related Events

Related Articles

Related Resources