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 with 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), the following steps will help to reduce the risk of contamination or growth from Clostridium botulinum:
Clean and sanitize your hands, all work surfaces, utensils, and equipment and 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.
High-acid foods such as fruit, pickles, sauerkraut, jams, jellies, marmalades and fruit butters will not support the growth of Clostridium botulinum and can be safely processed in a boiling water canner.
Tomatoes are a borderline high-acid food and require an acid, such as lemon juice or vinegar, to be added for safer canning.
Attempting to can foods in their fresh state without added liquid is not safe. Ensure that the food being canned is topped up sufficiently, in its can or jar, with suitable liquid, such as syrup, sauce, brine or acidifying agent.
When following currently tested recipes, do not substitute ingredients, change amounts or the jar size that is in the recipe, because this can cause the recommended temperature, time or pressure needed during pressure canning or boiling water canning to change. This 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.
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 gifting 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 or bottled 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, headache, double vision and dryness in the throat and nose, to respiratory failure, paralysis 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 11 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.
For more information on food safety tips for home canning and bottling, please visit:
Government of Canada's Home Canning Safety Tip Sheet
Government of Canada's Home Canning and Bottling of Fish and other Shellfish Safety Tips sheet
Food-Related Illnesses:Botulism
Partnership for Consumer Food Safety Education's Be Food Safe Canada Campaign
