Pressure Cooker or Pressure Canner??

Return to the canning menu.

If you aren't into major canning, form a co-op and share the expense among friends, family and neighbors. Years ago a couple of friends and I decided to learn how to can. We pooled our money and bought a brand new canner and we shared it for many years. Actually it was kind of fun getting together and we would spend a day canning green beans, tomato sauce or peaches and divide the bounty among us.

Miss Vickie Recommends
Pressure Canners:

Wisconsin Aluminum Foundry 21 1/2-Quart Pressure Canner

Wisconsin Aluminum Foundry 15 1/2-Quart Pressure Canner

Canning is a Science requiring updated,tested canning recipes, specialized equipment and accurate timing to process canned foods for safe consumption. If you want to be creative try painting, but don't attempt to alter safe, tested canning recipes.

Is It Safe To Use Pressure Cookers To “Can" Foods?

In a word - NO. Pressure cookers have less metal, are smaller in diameter, and use less water than pressure canners. The result is that the heat-up and cool-down times will be less than for the standard pressure canner. These heating and cooling times are part of the total processing time that was determinedin lab testing to establish a reasonable margin of safety for low-acid foods.

If the heating and cooling periods are shortened, then the process time at pressure may not be enough to destroy targeted microorganisms and provide a safe product. If the food is underprocessed, low-acid canned foods are unsafe and can result in foodborne illness, including botulism poisoning, if consumed.

During early years of canning in the 1940s, the new pressure saucepans were considered an alternative to large canners. It was thought that adding 10 minutes to the process times used by standard canners , that would be enough to keep food safe. That proved not to be the case, as pressure cookers came in several sizes and they were not all adequately tested. In addition, the way heat penetrates through food during the process is affected partly by the composition of the food, and not all foods and styles of preparation were tested back then. USDA published research in the late 1980s recommended not use pressure cookers for home canning.

Pressure Cooker Manufacturer Says it Can

Even though some manufacturers advertise their brand of pressure cooker as acceptable for use as a pressure canner, canning experts don't agree

Some manufacturers may offer process directions for pressure cookers. Consumers using this equipment will need to discuss processing recommendations with those manufacturers; the USDA and National Center for Home Food Preservation recommendation is to not use them for canning with our processes.

To be considered a pressure canner for USDA processes, the canner must be equipped with a wire canning rack and be able to hold at least four quart-size jars. There is no method to accurately convert processes intended for use with a regular pressure canner to ensure safety when canning in other types of equipment.


November 7, 2006, National Center for Home Food Preservation

Expert Says, Can the Creativity when Home-canning

MSU University News; August 02, 2002 -- Updating your recipes
Some people may think that any recipe can be canned at home, but that is not the case. You cannot whip up a batch of your favorite soup, pour it into canning jars, drop them into a canner and then serve it up without placing your family at risk of food poisoning. Safe canning recipes are thoroughly evaluated in a food testing lab where the ingredients are tested for  pH factors that will determine the correct processing time.

“There are many chances for creativity in cooking, but canning is not one of them,” says Paul. Safe recipes require testing to prevent botulism. So, even though its tempting to try home-canning  your special soup or sauce, she encourages everyone to play it safe and stick with tested recipes from reliable sources. It is not safe to guess on what processing time and pressure to use.

Sources on canning typically very widely. Someone might still be using grandma’s high school, domestic-science textbook, copyright 1918. Maybe you have an old USDA pamphlet dating from the 1940s or your mom's favorite heirloom recipes. Putting Food By, first published in 1973 is also still found in rummage sales and thrift stores. All of these sources were reputable in their day, but they are considere4d unsafe by today's standards. Everyone wants to know, “What’s wrong with them now?”

The USDA dramatically changed the canning guidelines and instructions in 1989 to incorporate the current, modern methods and improvements in food safety, so be sure your recipes are current and dated after that year. Food preservation is more precise, and therefore much safer than it was years ago. The most accurate, up-to-date, and dependable guidelines are in the current bulletins put out by the USDA, available free or at a small cost from your local county extension office. Read these pamphlets carefully, and follow their instructions to the letter.

Canning summer produce is a family tradition for some—for others, it may be a first attempt. But either way, creativity and canning aren’t a safe combination, says Lynn Paul, a food and nutrition specialist at Montana State University Extension. While many people may want to follow in the old heirloom canning recipes used by their grandparents, but canning requires current, tested recommendations and the right type of equipment. These recommendations are based on the food safety and quality, says Paul, but safety is by far the top priority.

Finally, Paul notes that what may seem to be a daunting list of do’s and don’ts is really meant to provide tasty and safe food. “Learn what you need to know and have fun this summer canning your produce.”

Recent Changes In Canning

Tomato canning recipes now require lemon juice or citric acid because some varieties of tomatoes may have lower acid levels than those we used in the past. See more about acidification.

Paraffin wax seals are no longer recommended because they will not prevent mold growth in jams and jellies. Use canning jars with seals and lids, and follow the directions from a recommended recipe.

Don’t use microwaves for home canning, even though you may find a few microwave-canning recipes in magazines. Microwaves can be extremely dangerous, especially with low-acid foods, because botulism bacteria could survive. Other unsafe canning methods include crockpots, ovens, dishwashers, open-kettle canning (where food is heated and poured into jars).

What Makes A Recipe Safe For Canning?

Safe canning recipes include the right mixture of ingredients, time and pressure. They require the use of proper canning equipment for the foods being processed. Paul only recommends recipes that have been tested to assure safety. This testing requires laboratory work to determine the right time and pressure (based on altitude and pH values) to kill botulism bacteria.