Why can't I cool down my pressure canner with water like I do when I'm using it to cook food?
The cool-down period of pressure canning is an important part of the processing. A high percentage of spoilage bacteria are killed during the cool-down period. If this cool-down period were eliminated by cooling the canner with running water, food would be under-processed, spoilage bacteria would survive and the food could be dangerous.
Additionally, sudden cooling and the resulting rapid
pressure change can break seals on processed jars and
draw liquid out of jars or break them.
Source: Pennsylvania State University Workshop on Home Food Preservation, May 1987.
Last update: Tuesday, May 05, 2009