Pressure canners area must for canning low acid foods. This includes all vegetables except acidified tomatoes. Meats, fish, and poultry must also be processed in a pressure canner. Dial gauges should be tested for accuracy before each canning season. Also check your pressure canner to see if the rubber gasket is flexible and soft, not brittle, sticky or cracked. If you need to replace the rubber gasket, make sure you know the brand and model number of your canner when you go to the store to purchase one. There are many styles of gaskets available, and you will not be able to judge the thickness and size of the rubber gasket by sight. Check the pliability of the washer on the air vent and the pressure release plug. Hold the lid to the light to make sure any small pipes or vent ports with openings are clean and open all the way through. Small vents can be cleaned with a small brush or a pipe cleaner.
Boiling water canners are needed for canning fruits, pickles, acidified tomatoes, jellies and jams. The canner should be deep enough to allow at least one to two inches of water to boil vigorously above the tops of the jars. Some of the new boiling water canners are designed for processing jams and jellies and are only deep enough for pint jars. If you plan to can in quart jars, look for a taller canner and measure the height of the canner so that there is space for a rack, the jars, at least one inch of water above the jars, and room for the water to boil rapidly without boiling over. Both types of canners should have a rack in the bottom to keep jars off the bottom of the caner. It may be a flat rack or a lift out type rack.
Jars. Inventory your jars and decide if you need to buy new jars. Inspect them for nicks, cracks, or chips—especially around the top sealing edge. Nicks can prevent lids from sealing. Very old jars can weaken with age and repeated use and may break under pressure and heat. New jars are a better investment over time than buying used jars at yard sales or flea markets. Use mason jars that are specifically designed for home canning. Although canning jars come in a variety of sizes from half-cup to half-gallon jars, processing times have not been developed for many foods in half-pint, 12-ounce, or 24 ounce jars. If a recipe does not specify a processing time for one of these jars, process according to the time given for the next larger jar. Half-gallon canning jars are only suitable for very acid juices such as apple juice and grape juice.
Lids. Use two piece lids consisting of a flat metal disc which has a sealing compound around the outer edge and a separate metal screw band. This is the only type recommended by the USDA. Always use new flat lids. The screw bands are reusable if they are not bent, dented or rusted. Do not reuse lids from commercially canned foods for home canning.
Some other items are helpful for home canning. A jar lifter is essential for easy removal of hot jars from the canner. A wide mouth funnel helps in packing small food items and jams into canning jars. A plastic bubble freer removes air bubbles from jars. Metal knives or objects should not be used as a bubble freer because they can scratch the glass making the jar more susceptible to breakage. A lid wand has a magnet on the end that helps remove lids from the hot water. A timer or clock is needed to determine the end of the processing time.
Finally, make sure that you have up-to-date canning instructions. The USDA canning guides were last updated in 2009. Major revisions were made about twenty years ago. Canning books published prior to 1994 will not have safe processing times and/or methods. The National Center for Home Food Preservation offers canning information and research tested canning recipes. Visit the Penn State Home Food Preservation Web Site for links to tested recipes.
Planning ahead can save you time, money, and frustration. Make it a happy, successful canning season by getting prepared before your harvest is ready.