Pack meat loosely in containers. Jars may lose liquid during processing if they are packed too tightly or too full.
Work with one glass jar or tin can at a time. Keep precooked meat hot while packing. Use boiling liquid—broth, meat juice, or water—if directions call for added liquid.
Two methods are used for packing meat:
Hot pack. Meat is precooked before it is packed in jars or cans. Boiling broth or boiling water is poured over meat before containers are processed in a pressure canner. (See [p. 8] for directions on how to make broth.) The temperature of food packed hot should be at least 170° F. at the time jars are closed or cans are sealed.
Raw pack. Meat is packed uncooked. Raw-packed meat usually is heated to 170° F. to exhaust—or remove—air from jars or cans before processing in a pressure canner.
Directions for canning in glass jars require exhausting air from raw-packed meat products, except meat-vegetable stew and raw pack poultry, with bone. These two products may be processed without exhausting if they are raw packed in glass jars according to directions on pages [20] and [22].
Directions for using tin cans include exhausting air from all raw-packed meat. It always is necessary to exhaust air from raw-packed meat in tin cans before processing because air has no way to escape after cans are sealed.
Exhausting air
To exhaust—or remove—air, set open jars or cans packed with raw meat on a rack in a large pan of boiling water. Water level should be about 2 inches below tops of jars or cans. Cover the pan. Cook meat in containers at slow boil until temperature at center of jars or cans registers 170° F. If a thermometer is not available, follow times given to cook meat until medium done.
When raw-packed meat is heated to 170° F., air is driven out of the food so that a vacuum will be formed in jars or cans after processing and cooling. Exhausting air also helps to prevent changes in the flavor of canned meat.