If you’ve seen the information on the Internet that claims pressure cookers should not be used to can foods, you need to know that this information stems from a misinterpretation of the USDA’s well-respected Complete Guide to Home Canning. Having read the guide carefully myself, it’s easy to see how the misinterpretation occurred.
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Don’t let this misunderstanding keep you from taking advantage of an efficient, lower cost way of preserving foods properly without purchasing a piece of equipment that can be used for only one purpose—canning. You can use pressure cookers for canning to prepare a wide variety of gourmet foods in addition to preserving foods. They are a favourite versatile kitchen helper. A good pressure cooker makes anyone a gourmet cook, allowing the preparation of entire nutritious meals in as little as 30 to 45 minutes.
To correct the misunderstanding, the USDA guide does not advise us to avoid pressure cookers for canning. Page 1-10 of the guide, under the heading Equipment and Methods Not Recommended, clearly states:
“Steam canners are not recommended because processing times for use with current models have not been adequately researched. Because steam canners do not heat foods in the same manner as boiling-water canners, their use with boiling-water process times may result in spoilage.”
We are advised not to use steam canners. Steam canning is not the same as canning with a pressure cooker. Steam canners cook with steam, and pressure cookers cook with pressure, as their names clearly imply. A quick Internet search reveals photos which clearly distinguish steam canners from pressure cookers.
You Need Pressure Cookers to Safely Can Low Acid Foods
To further clarify the misunderstanding, there are two types of food requiring two types of canning processes. The boiling water method is for high acid foods having no risk of botulism (botulism bacteria cannot live in an acid environment). The pressure cooking method is used for low acid foods that do carry the risk of botulism. Pressure cooking also destroys salmonella and staphylococcus.
The misinterpreted quote is referring to the boiling-water process used for canning high acid foods (with a pH of 4.6 or lower), not to the pressure method of canning. The USDA states that these foods,
“Include all fruits except figs; most tomatoes; fermented and pickled vegetables; relishes; and jams, jellies, and marmalades. Acid foods may be processed in boiling water.”
The acid in these foods is sufficient to prevent the growth of botulism bacteria, so they do not require pressure for processing. Again, the USDA is stating that steam canners are not recommended for preserving these high acid foods—boiling-water canners must be used.
The paragraph which has been misinterpreted as saying pressure cookers should not be used for canning, is not even referring to the method of canning that requires pressure cookers—to preserve lower acid foods (with a pH higher than 4.6). The USDA guide states:
“Vegetables, some tomatoes, figs, all meats, fish, seafoods, and some dairy foods are low acid. To control all risks of botulism, jars of these foods must be (1) heat processed in a pressure canner, or (2) acidified to a pH of 4.6 or lower before processing in boiling water.”
Reading this guide carefully yourself will help you understand that it is safe, and in fact is recommended to use pressure cookers for canning.
Pressure Cooker Specifications from the National Center for Home Food Preservation
As you can see, the website that steers us away from using pressure cookers for canning, is inaccurate in saying, “Even though some manufacturers advertise their brand of pressure cooker as acceptable for use as a pressure canner, canning experts don’t agree.”
Pressure cookers specifically recommended for canning that come with an 8-piece canning set (including a canning and a pressure cooker recipe book), are Fagor pressure cookers. Fagor 10-quart pressure cookers hold up to four 1-quart jars on the rack provided for canning. This size meets the exact specifications set forth by the National Center for Home Food Preservation (NCHFP), another respected authority on home canning.
Fagor pressure cookers are one of the three types of pressure canners specified by the USDA and the NCHFP. Fagor pressure cookers are weighted-gauge pressure canners capable of cooking at 10 or 15 PSI (pounds per square inch) as required for pressure canning.
Fagor, in business since 1954, the fifth largest appliance manufacturer in Europe, the leading appliance manufacturer in France and Spain, has more than 12,000 employees in 17 countries. Their products are available in 100 countries. Fagor America opened in 1992 and is known for re-introducing pressure cooking to the U.S. with their high quality stainless steel pressure cookers.
Fagor values the health of their customers and emphasizes specific requirements for canning with pressure cookers. All recipes in the canning recipe books supplied with the Fagor Pressure Cookers have been carefully tested for use with their 10-quart pressure cooker. Fagor cautions consumers to always follow the directions and timing in the pressure cooker recipe book provided with their canning set carefully, just like one would follow any of the canning charts supplied by the USDA, the NCHFP or the Ball Blue Book.
Fagor also specifies that no matter how you can your food, you should always carefully inspect the jars prior to consuming the food to be doubly safe. They recommend the Ball Blue Book of Preserving and the USDA’s Complete Guide to Home Canning for the most reliable information. They advise that recipe books written prior to 1989, the year the USDA updated their guidelines, should not be used.