Canning season will be here soon! As you are tending your garden for a summer harvest don’t forget to consider how you can preserve your bounty to enjoy this winter. The USDA and Center for Home Preservation recommend that canners are tested on a yearly basis. Over time, as the canner lid is bumped or just used, the calibration on a dial gauge canner can become inaccurate. Even gauges on new canners and replacement gauges need to be tested before use. Research-tested recipes for pressure canned foods are based on set temperatures and times to kill harmful bacteria. If your canner is weighted, it is mechanically accurate and does not need to be tested.
If the pressure is lower than that recommended for processing, the internal temperature of the food will not be adequate to kill all the bacteria and spores that can cause illness. Although a jar may seal if processed at a lower temperature, it does not mean that the food inside is safe. Processing foods at too low a pressure is a safety issue.
If a dial gauge is inaccurate and the processing pressure is higher than recommended, the food inside the jar may be overcooked and softer in texture than desired. This is not a safety issue but is a quality issue, especially when canning tender fruit.
If you have any questions, reach out to the Extension office by calling 304-478-2949 or just stop by with your gauge or lid.