Often considered a more intense method of canning, pressure canning is the method used to can low acid foods, such as meat, vegetables, and prepared foods such as soups. These foods require a higher temperature to kill bacteria (240°F), which must be achieved with pressurized steam. (You must use an actual pressure canner, not a pot or water bath canner, to can low acid foods.)
Before considering pressure canning, verify that your stove maintains a constant temperature as required. It is not recommended that you use a smooth top stove, as the heat fluctuates and can cause the pressure to drop below safe temperatures. Make sure that you have all of the equipment needed as outlined in my Getting started with Canning post!
A pressure canner is equipped with a locking lid and a gauge that allows you to monitor pressure. There are two types of gauge, a dial gauge and a weighted gauge. A canner with a weighted gauge will only have one safety valve on the top. A canner with a dial gauge (the gauge has a needle in the middle that resembles a clock hand) has a regulator, vent pipe, and a safety valve. A dial gauge must be tested annually to ensure that proper temperature is achieved. This can be done at many hardware stores and extension offices. A weighted gauge does not need to be tested unless there is visible damage.
A gasket lines the lid, which helps form a tight seal. Routinely inspect the gasket for nicks, rips, and tears. The pressure canner should also be fitted with a rack to keep the jars from touching the bottom.
Inspect the outside of the canner and lid for cuts, scratches, and dents. There is a safety vent and/or vent pipe (depending on model) on the top of the lid that should be checked for residue buildup.
Once you’ve inspected the equipment, prepare the recipe as directed. You can find tons of recipes for canning in the Ball Canning Book or the many canning websites available.
Fill the canner with 2”-3” of water and add filled jars that are fitted with two piece caps. Lock the lid into place and increase temperature to boil the water. Once the gauge has hit 10 PSI, the steam has reached the necessary 240°F required to properly can the foods. Begin timing from this point.
If you are canning at an altitude of over 1,000 feet, you will need to make adjustments. The Ball Fresh Preserving website has a downloadable chart that will tell you exactly how to adjust for your altitude.
Pressure canning is often considered scary, because of the heat and temperatures required. If you follow the safety techniques and proper canning practices, there is absolutely nothing to be scared of and you can soon be pressure canning like a pro!