Canning Fruit & Canning Tips
Did your strawberry patch yield a bumper crop? Were the ripe peaches at the farmers' market too tempting to pass up? Do you and your family enjoy "pick-your-own" days in local cherry orchards?
If you answered "yes" to any of those questions, you've probably experienced TMF (Too Much Fruit) Syndrome. Good news—you can turn that surplus into long-lasting treats such as jams, jellies, fruit "butters," and preserves that will delight your family and friends…and remind you of summer long into the cold, cheerless winter months.
"Canning" fruits (a misnomer, because you use glass jars rather than metal cans) is very satisfying and surprisingly easy. It's all a matter of using the right equipment and following a few simple but essential rules.
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 naturally high in acid.
- Cooking or candy thermometer. High-acid foods such as fruits can be preserved in water heated to 8°F or 9°F 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, below.) 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).
Guidelines for Preserving
- All preserves should be made in small amounts (about 4 cupfuls of fruit); recipes should never doubled.
- Wash glasses and jars in hot, sudsy water.
- Sterilize glasses and jars: Place a folded dish towel in the bottom of a deep pot and place the containers on it. Cover with hot water and bring to a boil. Simmer for 15 minutes, then cover and leave in hot water. Remove containers from the water about 5 minutes before using. They should be hot but not dry.
- Fill glasses or jars immediately: glasses to within 1/4" of the top, jars to within 1/8". Place lids on filled jars immediately. Seal according to manufacturer's instructions.
- If using paraffin instead of lids, melt it in a small container with a lip until it is hot but not smoking. Pour a 1/8" layer over the top of jelly, tilting the glass so that the wax touches all outer edges.
- Cover the canner and process according to recipe directions.
When Is It Done?
A thermometer is your best bet for timing the cooking of any preserve. Because temperature is affected by weather and altitude, we recommend that you test the boiling point of water each time you preserve. Adjust recipe temperatures accordingly (water boils at 212°F at sea level). Cook jellies to 8°F above the adjusted boiling point; jams and preserves need to reach 9°F above boiling.
When you're finished processing, remove the canning rack or use tongs to remove jars. Set them on towels or rack at least 1" apart. Cool completely for 12 to 24 hours. To test the seal, press the center of each lid. If the "dip" in the lid holds, the jar is sealed. If it bounces up and down, it isn't sealed. You may refrigerate unsealed jars and use them within 3 days; freeze them; or reprocess them in clean jars and new lids.
Pectin and acid both contribute to jelling. Unripe fruit contains more pectin than overripe fruit, so select unblemished produce that is ripe but still firm and include some unripe fruit as well. Although apples, crab apples, currants, grapes, gooseberries, plums, and cranberries are high in natural pectin, some cooks prefer to add commercial pectin, which comes in either liquid or powdered form, to assure a perfect jelly. Others combine low-pectin fruits, such as berries, with the juice of high-pectin fruits and add lemon juice to increase the acidity.
Jellies are made from fruit juice and sugar cooked together until the jelling point is reached.
In addition to your large kettle and long-handled spoon, you will need a jelly bag made of cheesecloth or flannel (nap side in), a rack or colander to hold the bag, and a large bowl to catch the juice. Do not squeeze the bag when straining juice for jelly or your finished product will be clouded. You will also need a ladle to fill the glasses.
To extract the juice from fruit, cover apples and other hard fruits with water and boil for 20 to 25 minutes; crush berries or grapes. Add only enough cold water to prevent burning and cook about 10 minutes. Do not overcook or the flavor and pectin content will suffer.
After the juice has been extracted, return it to the pot with sugar and cooked over moderate heat until the sugar dissolves. Then raise the heat and boil rapidly until the jelling point (220°F at sea level) is reached.
Making Preserves and More
Preserves contain whole berries or large pieces of fruit, and are not as thick as jams, which contain crushed or chopped fruits.
Fruit "butters" contain no butter; they are made by cooking fruit pulp with sugar until the mixture is thick but spreadable. You can use the leftover pulp from jelly-making, or you can start from scratch.
Conserves are made from more than one fruit and generally have nuts or raisins added toward the end of cooking.
Marmalades have pieces of fruit in a clear jelly. They are traditionally made from citrus fruits, but occasionally contain pineapple or other fruit.
All types of preserved fruit should be cooked slowly until the sugar dissolves and then boiled rapidly until the jelling point for jams (221°F at sea level) is reached.
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