Pressure Canning Gauge Testing

Home canning equipment must be in proper working order to guarantee the foods you preserve are safe to eat. A pressure canner with a dial gauge should be checked for accuracy annually to ensure accurate readings.

The Marais des Cygnes Extension District offers free pressure canner gauge testing services. We use a Presto gauge testing unit to check the accuracy of gauges on Presto, National, Maid of Honor and Magic Seal pressure canners. All American pressure canner gauges cannot be tested with this equipment.

To have your gauge tested, drop off the lid from your canner (with gauge attached) at our office in Paola or Mound City. Please allow one week for testing to be completed.

Our offices are open Monday – Friday, 8:00 am – 4:30 pm. Closed for major holidays.

Why is gauge testing important?

• Food Safety: Accurate pressure is essential for destroying harmful bacteria during canning.
• Quality Preservation: Over-processing (too high pressure) can affect food texture and quality.
• Recipe Accuracy: Recipes specify pressure levels; inaccurate gauges can lead to unsafe or poor-quality results.

What to expect from gauge testing:

• Testing procedure:The gauge or lid is placed on the tester, and the pressure is brought up to specific levels (5, 11, and 15 psi).
• Comparison:The reading on your gauge is compared to a calibrated master gauge.
• Results:If your gauge is off by more than 2 pounds, it's recommended to replace it.