# Pressure canner vs pressure cooker: why only canners are safe for canning Source: https://freezeandseal.com/blog/pressure-canner-vs-pressure-cooker Published: 2026-10-09 Publisher: Freeze & Seal **Short answer:** A pressure canner is a large pot built to hold jars at a controlled pressure, and USDA process times only apply to canners that hold at least four quart jars standing on the rack. A pressure cooker is smaller and is not a safe substitute for canning low acid foods. A canner can, however, double as a big pressure cooker, so a canner covers both jobs while a cooker covers only one. This page is for anyone holding a pressure cooker or an Instant Pot and wondering whether it can can green beans or stock. It explains what separates a canner from a cooker, why the four quart jar rule matters, what the National Center for Home Food Preservation (NCHFP) says about electric multicookers, and how to cook in a canner. The product table uses only listing facts for three models sold as cooker and canner combinations. ## The short difference Both pots trap steam to raise the boiling point above 212 F. The difference is what they are designed and tested for. A pressure canner is sized to hold jars on a rack, has a gauge or weight that lets you hold a specific pressure (10, 11, 12, 13, 14 or 15 psi depending on altitude and gauge), and is used with tested USDA or NCHFP recipes. A pressure cooker is built to cook food fast, often at one fixed pressure, and is usually too small to hold quart jars properly. Low acid foods such as vegetables, meat, poultry, seafood and stock must be pressure canned because boiling water cannot reach the temperature needed to destroy Clostridium botulinum spores. See [what foods need pressure canning](https://freezeandseal.com/blog/what-foods-need-pressure-canning) for the full list. ## Why the four quart jar rule matters USDA processing times are not just the minutes at pressure. They were developed in canners large enough to hold at least four quart jars, and the time it takes that full canner to heat up, vent and cool down is part of the heat the food receives. A small pressure cooker heats and cools faster, so jars processed for the published time get less total heat than the recipe assumes. That is why NCHFP does not recommend using pressure cookers smaller than this for canning, and does not recommend electric multicookers for pressure canning at all, because their temperature control has not been validated against the tested process. Our page on [canning in an Instant Pot](https://freezeandseal.com/blog/can-you-pressure-can-in-an-instant-pot) goes into that question, and [what size pressure canner you need](https://freezeandseal.com/blog/what-size-pressure-canner-do-i-need) helps you size a canner. Note: Do not use a pressure cooker or electric multicooker to can low acid foods with USDA times. Under processing can leave botulism spores alive in a sealed jar that looks normal. ## Three combination units from the listings Every model here is sold as both a cooker and a canner. The table is built only from the Amazon listings. | Model | Type | Capacity (listed) | Gauge or control (listed) | Other listed details | | --- | --- | --- | --- | --- | | Presto 01781 | Stovetop, aluminum | 23 qt; 7 quarts, 20 pints, 26 half pints | Dial gauge | Doubles as boiling water canner and large pressure cooker; 12 year limited warranty; works on smooth top ranges | | All American 921 | Stovetop, cast aluminum | 21.5 qt; about 7 quarts or 19 pints | Steam gauge plus regulator weight | Metal to metal seal, no gasket; gas, electric or flat top stoves | | CAREY DPC-9SS | Electric | 9.5 qt nonstick inner pot | Digital, automatic pressure regulation | Pressure cook, slow cook, steam and water bath modes; canning and steam racks included | Listing facts: cooker and canner combinations Note: The CAREY listing describes a canning function. It is an electric unit, and NCHFP does not recommend electric multicookers for pressure canning. Read our page on [electric vs stovetop canners](https://freezeandseal.com/blog/electric-vs-stovetop-pressure-canner) before relying on one for low acid foods. ## Can you cook in a pressure canner? Yes. Both the Presto 01781 and All American 921 listings describe the pot as a cooker as well as a canner. A big canner works well for large cuts, beans, stock and big batches of soup. Follow the maker's instructions for minimum liquid, never fill above the maker's maximum fill line for food, and avoid foods that foam or sputter, such as dried beans with lots of skins, unless the manual allows them. The trade off is size. A 21 to 23 quart pot is heavy and slow to come up to pressure for a weeknight dinner for two. If you mostly cook, a dedicated cooker is handier. If you mostly can, a canner that also cooks the occasional roast is the better buy. 1. Put in the rack and the amount of water or liquid the manual specifies. 2. Add food, stay below the maximum fill level, and lock the lid. 3. Vent steam for the time the manual gives before adding the weight or closing the petcock. 4. Bring to the pressure the recipe calls for and lower the heat to hold it. 5. Let pressure fall on its own before opening, unless the recipe says otherwise. ## Which one to buy If you want to can green beans, corn, meat, chili or stock, buy a stovetop pressure canner that holds at least four quart jars. The Presto 01781 is the low price route with a dial gauge, and the All American 921 adds a gasket free seal and a regulator weight. Both will also cook. If you only want quick dinners, a pressure cooker is the right tool, but keep it out of your canning. For more options, see the [best pressure canners](https://freezeandseal.com/best/best-pressure-canner) and the [pressure canning stage](https://freezeandseal.com/stage/pressure-canning). [Compare large pressure canners](https://freezeandseal.com/best/best-large-pressure-canner) ## Frequently asked questions **Can I can in an Instant Pot?** NCHFP does not recommend electric multicookers for pressure canning, including models with a canning button, because their processes have not been validated with USDA times. Use a stovetop canner for low acid foods. **Is a pressure canner the same as a pressure cooker?** No. A canner can cook, but a cooker is not a safe canner unless it is large enough to hold at least four quart jars and lets you hold the pressure the recipe calls for. **Can I water bath can in a pressure canner?** The Presto 01781 listing says it doubles as a boiling water canner. Leave the lid unlocked or the vent open so no pressure builds, and make sure water covers the jars by at least an inch. See [pressure canner vs water bath canner](https://freezeandseal.com/blog/pressure-canner-vs-water-bath-canner). **What pressure should I use?** It depends on your altitude and gauge type. Use the [pressure by altitude tool](https://freezeandseal.com/tools/usda-altitude-pressure) and confirm against the tested recipe. ## Gear guides for this topic - https://freezeandseal.com/best/best-pressure-canner - https://freezeandseal.com/best/best-large-pressure-canner - https://freezeandseal.com/best/best-electric-pressure-canner ## Sources - [National Center for Home Food Preservation](https://nchfp.uga.edu/)