[The information presented here will continue to be added to as I find time so please check the FYI section for updates on this page. Please note information on this page is copyright protected.]
This is a Canadian blog and as such I tend to promote Canadian methods and resources. However, I would be remiss not to include other valuable home canning resources. The canning recipes on this blog follow USDA processing guidelines. The canning instructions on this website are for altitudes of 1,000 feet (305 M) or less above sea level. Those canning at higher altitudes should follow the altitude adjustment chart for proper processing times and/or pressure. I do use reusable canning lid (eg. Tattler, 4everrecap, glass lids, glass inserts) that are not recommended by the USDA in addition to the metal snap lids recommended by the USDA. The reusable canning lids are every bit as safe as the metal snap lids. The only difference besides the absence of BPA is the manufacturers of the reusable canning lids have not paid to have the USDA test them.
Please note, from time to time references will be made to the USDA. It is important to understand that the USDA does not 'approve' or 'disprove' anything including recipes. Rather they make recommendations based on their research test findings. The USDA is the leading expert but not the only expert with respect to home canning.
Acidifying Tomatoes and Tomato Products:
Tomatoes are botanically a fruit but they hover right around the safe pH 4.6 for boiling water bath (BWB) and most tomato products can be pressure canned. The safe canning (USDA) guidelines are for all tomato products to be acidified using lemon juice or citric acid although vinegar (5% acetic acid) may be used in some recipes. Salsa has been indicated as a problem home canned food. For that reason it is recommended you use only tried, tested and true recipes from reliable sources for canning any canning product. [Note that any home canned tomato product on this blog meets those requirements and pH has been tested as well to ensure the product is canned using the safest method.] Tomatoes and tomato products should be acidified by adding:
- 1 tbsp (15ml) 100% pure no preservatives added lemon juice per 500 ml (pint) jar. Use only commercially prepared lemon juice that has been standardized. Do not use any lemon juice that contains sodium benzoate as that converts to benzene, a known carcinogen, under heat and acidic conditions.
- ¼ tsp (1 ml) citric acid per per 500 ml (pint) jar. I prefer using citric acid because it is shelf stable, doesn't impart a flavour into the tomatoes and doesn't contain sodium benzoate. It also is a lot easier to store
Altitude Adjustment Chart:
Botulism is a food poisoning caused by the toxin produced by the spores of Clostridium botulinum. The spores of C. botulinum are present are found naturally in soil. They are very heat resistant. The spores cannot grow in high acid (eg. home canned pickles, pH 4.6 or lower) conditions. Under anerobic, low acid conditions (eg. home canned vegetables, pH 4.6 or higher) the spores can grow and produce the toxin which is colourless, odourless and cannot be detected by taste. However, it only takes a very, very small amount of C. botulinum spores to make you extremely sick and could cause death. The spores are not destroyed in boiling water bath (BWB) which reaches a temperture of 100ºC (212ºF) but can be destroyed at the higher temper of 116ºC (240ºF) reached in a pressure canner (PC).
While the risk of C. botulinum spores being present in your jars of low acid foods (eg. vegetables, mushrooms, soups, stews, meats, dried beans, seafoods, stocks) always assume they may be present. Do not can any low acid food in a BWB canner! Always process low acid foods in a PC according to the proper processing time for that food, adjusting for altitude if necessary according to the altitude adjustment chart.
Useful articles on botulism:
Canadian Canning Resources:
Canadian Sources for Canning Supplies:
From time to time certain problems can happen when canning. The most common problem is seal failure. This will affect the food safety if it happens during storage. Other problems affect the quality of the food but the food is still safe to consume.
Certain Foods Should Not Be Canned at Home:
The following present problems in terms of either safety or quality for the home canner so should not be canned at home.
Other Canning Resources (non-Canadian):
Other Sources for Canning Supplies (non-Canadian):
Steam Canners: - official Utah State University position on steam canners (.pdf)
Useful Canning Articles:
Using Clear Jel:
© 2006 - 2016