Information update

Reminding Canadians of Potential Safety Concerns with Home Canning

Starting date:
August 20, 2013
Posting date:
August 20, 2013
Type of communication:
Information Update
Source of recall:
Health Canada
Food Safety
General Public
Identification number:


Health Canada would like to remind Canadians of the importance of good food safety practices while home canning.

With the renewed popularity of seasonal, local eating and the desire to prepare healthy foods at home, many Canadians are looking to home canning (usually in glass jars) to preserve food for later use. If, however, home canned foods are not properly prepared, they can cause serious illness such as botulism.

If you are home canning your own foods (such as jams, pickles, soups, sauces and seafood), these steps will help to reduce the risk of botulism:

  • Wash your hands, and clean and sanitize all work surfaces, utensils, and equipment. Keep them clean during all stages of the canning process.
  • Use a pressure canner when canning low acid foods. A pressure canner is a large pressure vessel optimized for canning and is not the same as a pressure cooker. Strictly follow the manufacturer's instructions for canning foods considered to be low-acid, such as seafood, meats, vegetables and sauces.  These low-acid foods must be processed in a pressure canner to destroy any Clostridium botulinum spores that might be present.
  • Foods such as fruit, pickles, jams, jellies, and marmalades will not support the growth of Clostridium botulinum due to their high acidity or high sugar content and can be safely processed in a boiling water canner. Make sure to follow the recipe.  Substitution of sugar with pectin may affect safety.
  • Tomatoes are a borderline high-acid food and require an acid, such as lemon juice, citric acid or vinegar, to be added for safer canning.
  • For many canning recipes, attempting to can foods in their fresh state without added liquid is not safe.  Ensure, when required, that the container is topped up sufficiently,  with suitable liquid, such as syrup, sauce, brine or acidifying agent.
  • When following tested recipes, do not substitute ingredients, change ingredient amounts or change the jar size that is in the recipe. This can cause the recommended temperature, time or pressure needed during pressure canning or boiling water canning to change, which can lead to bacteria remaining in the food.  Always follow the recommended recipes and processes along with the recommended temperature, time and pressure.
  • Each jar lid should be firmly sealed and concave (curved slightly inwards).  Nothing should have leaked from the jar, no unnatural odours should be detected and no liquid should spurt out when the jar is opened.
  • Clearly label your home-canned food, including the date it was canned. For best quality, use within one year from the date they were made.  
  • Be sure to store your home-canned food in a cool, dry place. Once the container has been opened, refrigerate leftovers immediately.
  • If you are buying or are given home canned products, ask about their preparation to help you to determine whether the proper safety steps were followed.

Always remember: never eat canned foods if you suspect the item has been tampered with, if the closure/seal has been broken, or if the container is swollen or leaking. When in doubt, throw it out!

Botulism is a serious illness that can result from eating improperly prepared canned foods. Botulism is caused by a bacterium - called Clostridium botulinum - that naturally produces toxins as part of its normal life cycle. The toxin that causes botulism is colourless, odourless, tasteless and invisible to the naked eye and is not necessarily destroyed by cooking.  Preventing the toxin from forming is therefore essential.

Symptoms of botulism range from nausea, vomiting, fatigue, dizziness, double and / or blurred vision and dryness in the throat, to respiratory failure, flaccid paralysis (lacking muscle tone) and, in some cases, death. The onset of symptoms is generally from 12 to 36 hours after ingesting the toxin. Recovery can take several weeks to months.

It is estimated that there are approximately 4 million cases of food-related illnesses of all types in Canada every year.  Many of these illnesses could be prevented by following proper food handling and preparation techniques.

It is important to understand the principles behind home canning so that food is produced safely at home. If necessary, consider taking short courses on food canning that are often available locally across the country.

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