In addition to planting your spring garden and reviewing the latest food safety materials, you should consider having your pressure canner gauge tested. Today’s pressure canner may have a dial gauge for indicating the pressure or a weighted gauge, for indicating and regulating the pressure.
Weighted gauges will either keep rocking gently or make a frequent jiggling noise to indicate that the correct pressure is being maintained. Read the manufacturer’s instructions to know how a particular weighted gauge should rock or jiggle. Weighted gauges do not require testing.
Check dial gauges for accuracy before use each year. Gauges that read high cause under-processing and may result in unsafe food. Low readings cause over-processing. Pressure adjustments can be made if the gauge reads up to 2 pounds high or low. Replace gauges that differ by more than 2 pounds.
Many UF/IFAS Extension Offices have pressure gauge testers and are willing to test yours for accuracy. It is always best to call for an appointment to insure that the FCS Agent is going to be in when you arrive. Don’t remove the gauge but bring the entire lid. If you prefer or if you find that your extension office does not offer this service, Presto will test gauges at no charge. For more information, phone Presto Customer Service: 1-800-877-0441 or firstname.lastname@example.org.
Handle canner lid gaskets carefully and clean them according to the manufacturer’s directions. Nicked or dried gaskets will allow stem leaks during pressurization of canners. Keep gaskets clean between uses. Gaskets on older model canners may require a light coat of vegetable oil once per year. Gaskets on newer model canners are pre-lubricated and do not benefit from oiling. Check you canner’s instructions if there is doubt that the particular gasket you use has been pre-lubricated.
Lid safety fuses are thin metal inserts or rubber plugs designed to relieve excessive pressure from the canner. Do not pick at or scratch fuses while cleaning. Use only canners that have the Underwriter’s Laboratory (UL) approval to ensure their safety.
Replacement gauges and other parts are often found at stores that sell food preservation equipment or from canner manufacturers. When ordering parts, be sure to provide your canner model number and describe the parts that you need.
Remember, pressure does not destroy microorganisms, but high temperatures applied for an adequate period of time do kill microorganisms. The success of destroying all microorganisms capable of growing in low-acid, canned food is based on the temperature obtained in pure steam, free of air, at sea level. At sea level, a canner operated at a gauge of 10.5 pounds provides an internal temperature of 240o.
For more information, contact your County Extension Family and Consumer Sciences Agent.