Food Preservation: Basics for Canning Fruit

Fruits can be canned with the boiling water bath method because they contain high enough acid levels to prevent the growth of Clostridium botulinum spores and the production of botulism toxin. Additionally, when fruits are properly canned, they are heated long enough at high enough temperatures to destroy spoilage-causing microorganisms.

Equipment

A water bath canner can be any large metal container with a fitted lid deep enough to fit a rack on the bottom, the jars, 1 to 2 inches of water above the jars, and 2 to 4 inches of space to allow for boiling.

A pressure canner also may be used in place of a water bath canner if it is deep enough. Place the lid, but do not fasten it. Leave the petcock and/or vent open so steam can escape and pressure does not build up during heating. As with a water bath canner, the jars need to be covered with 1 to 2 inches of water during processing, and space for boiling should be considered.

Use standard canning jars and lids. Commercial food jars, such as mayonnaise and coffee jars, are not recommended because they might not properly seal and are more likely to break than standard canning jars. Check jars, ringbands and lids for defects. Look for chips, cracks, dents, rust and anything else that will prevent airtight seals. Wash jars in hot soapy water and rinse well.

Prepare two-piece metal lids according to manufacturer's directions. Ringbands may be reused if they are not rusted, dented or damaged; lids may be used only once.

Preparing the Produce

Choose fresh, firm fruits for canning. Wash all fruit thoroughly regardless of whether or not it will be pared. Do not soak; soaking might cause the fruit to lose flavor and nutrients. Handle gently to avoid bruising.

Preventing Darkening

Some fruits darken when peeled or cut and then exposed to air. Choose one of these treatments to retard this natural occurrence while preparing fruit for canning:

• Use a commercial ascorbic acid mixture—available in grocery and drug stores—prepared according to package instructions.
• Drop fruit in a solution of 1 teaspoon or 3,000 milligrams ascorbic acid (vitamin C) and 1 gallon water. Vitamin C tablets also may be used. Drain fruit before proceeding.
• Drop fruit into a citric acid or lemon juice solution (1 teaspoon food-grade citric acid or ¾ cup lemon juice to 1 gallon water). Drain fruit before proceeding.

Sweetening Options

Sugar helps canned fruit hold its shape, color and flavor, but it is not needed to prevent spoilage. Fruits also can be packed in hot water or juice. Processing is the same for unsweetened and sweetened fruit. Any of the following may be used to provide sweetness.

Sugar Syr​up

Mix sugar with water and heat until the sugar dissolves; skim if necessary. Use proportions for the sweetness you desire. The table below may be used as a guide and makes enough syrup for a 9-pint canner load.

Juice

Unsweetened apple juice, pineapple juice or white grape juice may be good options, depending upon the type of fruit being processed. These juices can be added either diluted or undiluted, based upon personal preference. Juice can also be extracted from the fruit itself. To extract juice, thoroughly crush ripe, sound, juicy fruit. Heat to simmering (185°F to 210°F) over low heat. Strain through a jelly bag or cheese cloth.

Sugar Mixed Directly With Fruit

Add ¼ to ½ cup sugar to each quart of prepared fruit. Bring to a simmer over low heat. Pack fruit while it's hot in the hot juice that cooks out.

Sweeteners Other Than Sugar

Light corn syrup, light brown sugar or mild-flavored honey can replace as much as half of the sugar used in canning fruit. It is best not to use molasses, sorghum or other strong-flavored syrups; their flavors overpower the fruit flavor and might darken the fruit.

Artificial Sweeteners

Some artificial sweeteners can be added to liquids before canning. Other sweeteners should be added to fruit canned in plain water just before serving. Saccharin-based sweeteners can turn bitter during processing. Aspartame-based sweeteners lose their sweetening power during processing. Check labels for equivalents to the amount of sweet flavor desired.

Canning Juice

Grape Ju​ice

Choose fruit of good quality for eating fresh and cooking. Sweet, well-colored, firm, mature fruit work well. An average of 24.5 pounds will produce 7 quarts; 16 pounds will produce 9 pints. Follow directions for preparation of juice as outlined in the table at the end of this fact sheet.

Apple Juice

Good quality apple juice is made from a blend of varieties. For best results, purchase fresh juice from a local cider-maker within 24 hours after it has been pressed. Follow directions for preparation of juice as outlined in the table at the end of this fact sheet.

Filling Jars

Raw Pack Method

Place raw prepared fruit into jars and cover with hot syrup, juice or water. Pack tightly because raw fruit shrinks during processing. Raw packed fruit is more likely to float. Check the table at the end of this fact sheet for the correct amount of headspace to leave between the top of the fruit and the jar lid.

Hot Pack Method

Heat fruit in syrup, water, extracted juice or steam before placing it in jars. Pack loosely and cover with desired hot liquid. Check the table at the end of this fact sheet for the correct amount of headspace to leave between the top of the fruit and the jar lid.

Sealing Jars

Remove trapped air bubbles by sliding a nonmetallic spatula around the inside of the jar walls. If needed, add more liquid. Wipe the jar rim with a clean, dampened paper towel to remove any food particles. Place prepared lids on jars and metal ringbands. Screw metal bands down, fingertip tight. Avoid overtightening.

Preparing the Canner

Fill canner halfway full with water. To prevent jar breakage, preheat the water to 140°F for raw packed fruits or to 180°F for hot packed fruits. Place closed jars in canner and add boiling water as needed to bring water 1 to 2 inches over the jar tops. Cover the canner with the lid and turn burner to highest heat setting. Bring the water to a vigorous boil. Lower the heat setting to maintain a gentle boil, and start timing. See the table at the end of this fact sheet for specific processing times. Add boiling water as needed during the processing. When processing is complete, turn off heat and let stand for 5 minutes. Remove canner lid and use a jar lifter to remove jars. Then place them on a rack, dry towel or newspaper. Avoid placing jars on a cool surface as this might cause them to break. Do not tighten ringbands or touch the lids until jars have cooled. Allow the jars to cool, undisturbed, away from drafts for 12 to 24 hours.

Checking Seals and Storage

Listen for the familiar "ping" and look for the slight depression in the lid's center to know that it has properly sealed. Remove the ringbands, wipe jars with a damp cloth, and add labels. Store in a cool, dry, dark place.

Signs of Spoilage

If a jar does not seem completely normal before or after opening, do not use. This includes leaking jars, bulging lids and jars that spurt when opened. If the food looks spoiled, foams or has an off odor during preparation, discard it.

References
Andress, E., and J. Harrison. So Easy to Preserve. 6th ed. Athens: University of Georgia Cooperative Extension Service, 2014.
United States Department of Agriculture. Complete Guide to Home Canning, Agriculture Information Bulletin No. 539. 2009.