Canning basics: What qualifies a pressure cooking device as a canning device?
Like the old gradeschool analogy, “a Cadillac is a car, but a car is not a Cadillac,” a pressure canner is a pressure cooker, but a pressure cooker may not necessarily be a pressure canner. What qualifies a pressure cooking device as a canning device?
To be safely used for pressure canning, a pressure device must be able to hold at least 4 quart jars standing upright with the lid secured. It should also have a way to regulate pressure (with either a weighted gauge or an accurate dial gauge), as well as a tight-fitting lid and a functioning exhaust vent (or petcock) and safety valve.
While some pressure cookers meet these criteria, not all do. Smaller devices have less metal, and their smaller diameter means that they use less water than pressure canners. These attributes result in the come-up times and cool-down times (i.e., the amount of time it takes for the device to come up to processing pressure and to naturally cool down to 0 pounds pressure at the end of processing) being shortened. Come-up and cool-down times are part of the overall processing and have been taken into account when determining the processing time for each specific recipe. Shortening these times may mean that the food is underprocessed and thus unsafe. Since botulism is a significant concern when it comes to processing low-acid foods, ensuring correct processing times (from the very start to the very end) are crucial.
Other devices not recommended for canning include electric pressure cookers and multi-cookers. Recent testing has shown that these cookers do not reach high enough temperatures for a long enough time period to kill botulinum spores.
For further information, visit the National Center for Home Food Preservation (NCHFP) website or contact your local Cooperative Extension Office.
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Revised July 2025