CanningUSA.com

The principle of home canning is to process the jars and their contents by controlling the time and temperature of the process.The high temperature must be maintained long enough to kill all bacteria and to cause the contents to expand, forcing the air out of the jars. As the jars and contents cool, the contents and air contract, creating a vacuum and sealing the jars. The same principle holds true for canning with cans which aren't presently addressed at this Web site.

Raw Pack, Cold Pack and Hot Pack methods for processing are determined by the recipe. All recipes at this Web site will include instructions on which method to use. We address each of these methods in our videos.

Raw pack normally refers to placing uncooked meat or fish into a canning jar with the intention of cooking the contents during processing in a pressure canner, sometimes referred to as a pressure cooker.

Cold pack normally refers to fruits, including some home canned tomato recipes. Like raw pack, the contents are placed into the jars while they are at room temperature and hot liquid is poured over the contents. However, the intention is not to cook the product during processing in a water bath canner or pressure canner, depending on the recipe and acidity level of the food, but, simply to preserve the contents. Two good examples of this are home canned whole tomatoes (as shown in Video 3) and apricot halves (as shown in Video 2), neither of which should be fully cooked during the canning process.

Hot pack refers to any product that is cooked before the contents are placed in jars. This is the most common form of home canning packing and is used for jam, jelly, pie filling, tomato sauce, soups and broths, stews and poultry. This subsequent processing in a water bath canner or pressure canner is determined by the acidity level of the food. For step-by-step instructions on how use the hot pack method for home canning with photos, see Canning with Caps and Lids.