The modern homemaker is often inclined to depend upon commercial agencies for preservation of her winter's supply of food or else to rely upon fresh foods. The latter method is extremely expensive and not altogether satisfactory since vegetables, particularly, may change in nutritive value during shipping and marketing. Home canned and dried foods are usually more economical and often more tasty.
Canning is the process whereby food is sterilized and kept under sterile conditions in which bacteria, yeast, mold, etc., are not allowed to grow.
Firm, ripe fruits which show no signs of decay and few blemishes should be selected. Vegetables should be canned while they are yet tender and full flavored. They should be gathered early in the morning and canned shortly thereafter.
After essential preparation such as peeling, shelling and washing, foods either may be cooked and placed in the jar, or may be can-cooked, that is, cooked or processed in the can. In the can-cooked method, the food is packed in the can either raw,blanched, or precooked. Since blanching and precooking cause loss of flavor and nutritive value, they are used only in cases where they aid in peeling, in packing, and in preventing excessive shrinkage in the cans. The only foods which need to be precooked are asparagus, green beans, spinach and meat; others may or may not be, as desired. Blanching may be done by dipping in hot water for a few minutes which makes the removal of tomato and peach skins easier. Precooking is most satisfactorily done by steaming.
All jars and lids should be sterilized. This is done by placing them in water kept boiling for 15-20 minutes. Do not let the interior come in contact with unsterile materials before using. Do not boil rubber rings; soak them in soda solution made with 1 tsp. soda per cup of water. After the food and cans have been carefully prepared, in the can-cooked method pack the cans firmly and securely, but not too tightly. Exceptions to this rule are peas, shelled beans, corn and meat which should be packed loosely to insure thorough sterilization. Cover with hot water to within 1/2" of jar top and 1 tsp. salt per quart of food for vegetables. In the case of fruits, a sirup of desired consistency usually takes the place of water. Place the lids and tighten as much as possible with thumb and finger, or tighten completely and then turn back 1/4".