Some would say there is nothing as beautiful as a jar of fresh canned produce sitting on a shelf. Many times recipes used in home canning may be handed down from generation to generation and, in some families, the equipment needed to prepare them is also. Home pressure canners are no exception.

Many canners are passed down or bought at estate sales or yard sales. Often there’s no way to know if they are working properly without being tested. Even newer canners should be tested to ensure the safety of the food being processed.

If a canner isn’t working properly the foods in the jar can be under-processed, which even in a pressure canner, can increase the chance that botulism spores may still be present in the jars. It is important to note that pressure canners and boiling water canners are not the same thing.

Pressure canners for use in the home have been extensively redesigned in recent years. Models made before the 1970s were heavy-walled kettles with clamp-on or turn-on lids. They were fitted with a dial gauge, a vent port in the form of a petcock or counterweight, and a safety fuse. Modern pressure canners are lightweight, thin walled kettles; most have turn-on lids.

They have a jar rack, gasket, dial or weighted gauge, an automatic vent/cover lock, a vent port (steam vent) to be closed with a counterweight or weighted gauge, and a safety fuse.

Pressure does not destroy microorganisms, but high temperatures applied for an adequate period of time will kill microorganisms. The success of destroying all microorganisms capable of growing in canned food is based on the temperature obtained in pure steam, free of air. A canner operated at a gauge pressure of 10.5 pounds provides an internal temperature of 240°F.

Boiling-water canners are made of aluminum or porcelain-covered steel. They have removable perforated racks and fitted lids. The canner must be deep enough so that at least 1 inch of briskly boiling water will be over the tops of jars during processing. Some boiling-water canners do not have flat bottoms. A flat bottom must be used on an electric range. Either a flat or ridged bottom can be used on a gas burner. To ensure uniform processing of all jars with an electric range, the canner should be no more than 4 inches wider in diameter than the element on which it is heated.

The type of canner you need is determined by what food you are processing.

A pressure canner is essential for canning low-acid vegetables, meats, fish, and poultry. A boiling water canner is needed for canning other foods such as fruits, pickles, jellies and jams.

Green beans and tomatoes are among the most popular vegetables for home canning. Because of their low acidity, vegetables such as green beans must be processed in a pressure canner.

Test equipment before the canning season begins. It takes between 15 to 30 minutes and requires the canner lid, gauge and the rubber seal. If a dial tests off by more than one or two pounds it should be replaced.

Pressure canners with dial gauges should be tested yearly to check for accuracy. The Faulkner county office of the University of Arkansas, Division of Agriculture Extension Service has the equipment to test home canners. Pressure canners with jiggler-style gauges instead of dial gauges are not tested. These gauges are supposed to maintain their accuracy. 

There is a renewed interest in preserving foods today at home. Gauges will be tested at no charge, at the Faulkner County Extension service office located in the Faulkner County Natural Resource Center at 110 South Amity in Conway. This is for dial gauges only. Please call our office ahead of time to arrange to have yours tested.

Melanie Malone will be offering food preservation workshops in Conway this summer on June 1. High acid foods such as tomatoes and salsa from 9 a.m. to noon and Jams and Jellies from 1-4 p.m. and pressure canning, for low acid foods will be taught on July 13 from 9 a.m. to 2 p.m. Each class is $10, hands on and participants will leave with a jar of the product made.

Individuals who would like to take the food preservation workshops, have questions concerning canning or want to test a canner, come by the Faulkner County Cooperative Extension service. Malone can be contacted by email at mmalone@uaex.edu or by calling me at the office at 501-329-8344.

In addition to testing home canners, the Extension Service has free publications with updated U.S. Department of Agriculture recommendations for home canning. If your home canning recipes are older than 5 years old, it is time to come get new ones with the latest recommendations.