Before you start, assemble the following items in your kitchen:
- Heavy 8- to 10-quart kettle with a large, flat bottom. A pot this size allows the preserves to boil quickly and evenly.
- Canning rack. Not essential but helpful, this device has high handles that make it easy to remove jars from hot water. Any large pot can be used if it has a rack, a tight-fitting lid, and is deep enough to allow one inch of water to boil briskly over the tops of the jars.
- Glass jars with screw-on lids. You may buy canning jars or recycle commercial jars. Glasses and jars that are not nicked may be reused, as may the screw bands that hold the lids in place but the flat lids must be new. The most practical jar sizes are 6 ounces to 1 quart.
- Pressure canner. Useful if you’re preserving low-acid foods such as vegetables; an ordinary stockpot with a tight-fitting lid is fine for preserving fruits, which are high in acid.
- Cooking or candy thermometer. High-acid foods such as fruits can be preserved in water heated to 8° or 9° above boiling (212°F) for a length of time specific to each fruit.
- Long-handled spoon.
- Large piece(s) of cheesecloth.
- Paraffin wax. Necessary only if you're not using standard two-part screw-on lids or clamped glass lids.
- Commercial pectin. A necessary addition if you’re canning low-pectin fruit such as berries and peaches, and often required even with high-pectin apples and grapes if the fruit is too ripe. (See About Pectin.) Commercial pectin comes in powdered and liquid forms; they are not interchangeable. Use the pectin type specified in the recipe.
- Long-handled tongs for removing jars (if you’re not using a canning rack).