Use the freshest produce possible for canning. Amelia Jeanroy of "Canning and Preserving for Dummies" recommends that you pick the fruit yourself. Don't use fruits or vegetables with blemishes, even if you cut them out. Other foods that you may can include sauces, relishes and meats.
Jars and Lids
Canning jars are made from tempered glass so they will not react adversely to high heat. Jars and lids must be sterilized before the canning begins. To sterilize jars, put them in a water bath canner or large stockpot, fill or cover them with hot water and boil for 10 minutes. In "Preserving Summer's Bounty," Susan McClure provides specific instructions for sterilizing jar lids: "Wash them in hot soapy water or the dishwasher, and rinse them well. Then simmer the metal lids and screw bands, remove from heat, and leave in hot water until ready to use." McClure recommends reusing your canning jars but lids may only be used once.
Water Bath Canners
Water bath canning is used to make canned fruits, jellies and pickles. A water bath canner must be deep enough to cover the lids of jars inside the canner by at least 1 inch, leaving a couple of inches space for boiling. Jars inside the canner should be placed on a metal rack at the bottom of the canner, and they should not touch each other. A large stockpot can serve as a water bath canner.
Pressure canning is used to preserve low-acid foods like some vegetables and meats. The acid content of these foods means that they may contain harder-to-kill bacteria. But a pressure canner, which reaches a temperature of 240 degrees Fahrenheit, can safely eliminate these bacteria. Newer canners have a weighted gauge that controls the pressure inside the canner.
Pay close attention to recipes while canning. Flavors in ingredients that were only slight at the time of canning may become magnified during the canning process. Because canning is such a sensitive process, jars or ingredients may also easily become contaminated if you're not careful. Review cooking times and pressures for each recipe before you even start.