It is very important to have clean utensils, cloths, and work surfaces, including cutting boards and countertops. Jars and lids must also be absolutely clean. Lids must be free of dents. Use flat-lid seals only once. Reuse screw-top lids only if they are rust-free and not bent. Begin by assembling and cleaning your equipment. Wash jars, lids, and screw tops in warm, soapy water; and rinse thoroughly. You will need an additional saucepan for cooking produce.
Place clean flat-lid seals and empty jars standing upright on the rack inside your canning pot and fill pot with water to cover 1 to 2 inches above rim of jars. Hint: To prevent flat lids from floating, place them underneath the jars before filling the pot with water. Bring water to a simmer. Jars must simmer at 180 degrees for a minimum of 10 minutes before they will be ready to use.
Follow the recipe exactly. You cannot substitute fruits or vegetables, because the sugar-to-acid ratio must be precise. Wash all fruits and vegetables thoroughly, but do not soak them. Remove the stems, hulls, pits, skins, and cores (according to your recipe instructions), and cut away all soft or bruised spots, as well as any places where skin is broken.
Always cook fruits and vegetables in a non-reactive (stainless steel or enamel) saucepan. This is important
because some substances can react with food, giving it an unpleasant, metallic taste.
Use the jar lifter to take a jar from hot-water bath. Pour out any hot water that may be in jar. While jar is still wet and warm, put stainless-steel funnel in its mouth. Ladle in hot jam, or whatever you are canning, making sure to leave the amount of "head space" specified in your recipe. This space is essential to achieve a proper seal. Wipe jar lip with clean, damp cloth to remove spillage. Using a pair of tongs, lift a flat-lid seal from rack; place on jar, and secure screw top.
Boiling Water Bath
The boiling water bath process will sterilize your jars. Using the jar lifter, lower filled jar into boiling water and rest it on the rack in the canning pot. Place them 1 inch apart, away from sides of the pot. Repeat this procedure, one jar at a time, until all jars are filled and covered by 1 to 2 inches of water. Again, the 1- to 2-inch level is crucial in order to achieve a proper seal. Cover pot and keep at full boil for time specified in recipe. Remove jars with lifter; cool for 24 hours on wire rack.
Before putting the cooled jars away, test each seal. Press center of lid; it should stay rigid. Or, remove screw top, grasp edges of lid and lift. If lid flexes or comes off, store the food in the refrigerator and use within 1 week. If the seal is good, label the jars and store them in a cool, dry place for up to a year.
If you find any of the conditions listed below after the jars have been stored away, destroy the contents so they will not be eaten by people or animals.
Then discard all metal lid seals: broken seals, bulging lids, mold in contents, around seal or underside of lid, small bubbles in contents, spurting liquid, caused by pressure from the inside as jar is opened, off odor, mustiness.