HE-129
Using and Caring for Your
Pressure Canner
William D. Evers, Ph.D, and April C. Mason, Ph.D. Foods and Nutrition Extension Specialists
Using Pressure Canners In Home Canning
It takes higher-than-boiling temperatures to kill the dangerous organisms and their spores that cause spoilage in low-acid vegetables, meat, poultry, and fish. The only way to obtain these temperatures is to keep steam confined until it builds up pressure, thus raising the temperature above the boiling point of water, which is 212° F. A pressure canner is designed to do just that. For instance, at 10 pounds of pressure the internal temperature of a pressure canner is 240°F.
The pressure canner often used for home food processing is a 16-quart model. It is deep enough to hold a rack and seven quart jars, with room at the top for the canner lid.
Timing
Accurate timing is extremely important to the processing of foods in a pressure canner. Timing tables are available from the canner manufacturer or from U.S. Department of Agriculture and Purdue University Cooperative Extension bulletins.
A fully loaded canner takes a long time to heat and cool. This time is taken into account in the processing times given in tables. Do not decrease recommended processing times, because spoilage organisms and heat resistant spores may not be destroyed. To can safely, use directions given specifically for your pressure canner.
Old Pressure Canners
Before canning with pressure canners that have not been used for several years, it is a good idea to replace vital parts such as the dial pressure gauge, gasket, and safety plug. If the canner is an older model made by a company that is no longer in the business, check with
your County Extension office. They can give names of manufacturers that may be able to supply parts and instruction booklets for these canners.
Pressure Cookers (Saucepans or Pressure Pans)
A pressure cooker can be used for food processing if it:
•	is equipped with an accurate indicator or gauge.
•	can control pressure at 10 pounds (240°F).
•	is deep enough to hold jars standing on a rack with room at the top for the lid.
This type cooker usually holds three or four pint jars, and it is practical for canning only when processing a small amount of food at a time. The small cooker, with less metal and a smaller load, heats and cools more quickly. While this is a big advantage in regular food preparation, it is not in canning, because shortening the process may prevent destruction of spoilage organisms.
Recommendations:
Follow the directions for canning which are given in the instruction book that came with your pressure cooker (saucepan, pressure pan). If the instruction book is unavailable for the pressure saucepan, add 20 minutes to the processing times printed in USDA Bulletin HG-8, “Home Canning of Fruits and Vegetables,” or another reliable canning booklet. Make sure that the weight on the pressure cooker is made for 10 pounds of pressure. If it is less than 10 pounds, the canning times may not be sufficient to kill all undesirable organisms. Some pressure cooker manufacturers have a special regulator for operating their pressure saucepans at the standard canning pressure and time.
Cooperative Extension Service, Purdue University, West Lafayette, IN 47907