Canning basics: The difference between volume capacity and jar capacity.
Looking to acquire a new (or used) pressure canner? One consideration when evaluating whether a pressure canner will suit your needs is the size of the device. It’s important to distinguish between volume capacity and jar capacity – they are not the same. The documentation for the pressure canner (be sure to review it!) will provide information on capacity as well as how to correctly fill the canner.
For example, the Presto 16-quart Pressure Canner and Cooker will hold 16 quarts of liquid. But it will hold a load of only 7 quart jars, or 10 regular mouth pint jars, or 8 wide mouth pint jars when pressure canning – and, quart jars won’t fit if this particular pressure canner is used as a boiling water bath canner.
Furthermore, even though this specific device can contain a total of 16 quarts of liquid, when pressure cooking, the total amount of food that can be cooked at one time is significantly less than that.
Always be sure to review the device’s manual for safe operation and recipe-specific instructions for both pressure canning and pressure cooking.
Brought to you by the UC Master Food Preservers of El Dorado County
Last updated July 2025