Testing your pressure canner for accuracy
Be prepared for canning season by making sure your pressure canner gauge is accurate to prevent foodborne illness.
June 20, 2017 - Author: Kara Lynch, Michigan State University Extension
Do you use a pressure canner to can food? Did you know that if you have a dial gauge on your canner that you should have it checked for accuracy? Michigan State University Extension offers pressure canner gauge testing so you can check to see if your pressure canner gauge is displaying an accurate pressure reading. Without an accurate pressure gauge, you can place those that eat your home canned food at risk for dangerous foodborne illnesses, such as botulism.
Many county Extension offices have a pressure canner gauge tester. Just bring in your gauge or the canner lid and it can be tested for accuracy. Some gauges can be removed easily, but others can feel like they are cemented to the lid. If you can’t remove it, bring the whole lid in, and the testing can be done while the gauge is attached to the lid.
If your gauge is off by more than 2 pounds of pressure (psi), your gauge is not accurate and the food you are processing may not be cooked thoroughly or processed accurately. The next step would be to send the gauge in to the manufacturer who can replace it. Your local MSU Extension office can also inspect the lid for proper seals and vents. You may want to contact the local office before bringing it in to find out if there is a tester in your county and when an educator will be in your county to do the inspection.
Weighted gauges use a weight that causes the loud “jiggle” sound that most people commonly associate with home canned foods. The weighted gauges do not need to be calibrated but should be evaluated for cracked gaskets and clogged steam vents.
It is best to do this test annually, at the beginning of the summer, before you need to use the canner. Don’t wait until the last minute to bring it in, as you need to allow for time for sending in the gauge if necessary. MSU Extension has resources on food preservation, including pressure canning, and recommends following tested recipes and safe food handling when preserving food.
