MSU Extension

Pressure canning is the only method recommended by the U.S. Department of Agriculture for safely canning low-acid foods such as vegetables, meats and fish. Low-acid foods must be canned at a temperature of 240 degrees F or higher and held there for the time specified in the recipe to destroy the bacterial spores naturally present in these foods. Pressure canning utilizes pressurized steam to reach this superheated temperature. This pressurized heat destroys the potentially harmful bacterial spores. As the jars cool, a vacuum is formed, sealing the food in the jars and preventing any new microorganisms from entering and spoiling the food.

Learn about pressure canning basics from this Michigan Fresh fact sheet.