Fruits can be canned using 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 properly canned fruits are heated long enough at high enough temperatures, spoilage causing microorganisms are destroyed.
Equipment
A water bath canner can be any large metal container with a fitted lid. It must be deep enough to fit a rack on the bottom, the jars, and 1 to 2 inches of water above the jars. Space for boiling should also be considered.
A pressure canner that is deep enough may also be used in place of a water bath canner. Place the lid, but do not fasten it. Leave the petcock and/or vent open so steam can escape, and pressure does not increase 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 spaghetti sauce and pickle jars, are not recommended because they might not properly seal and are more likely to break than standard canning jars. Check jars, screw bands, and lids for defects. Look for chips, cracks, dents, rust, and anything else that will prevent airtight seals. Wash in hot soapy water and rinse well.
Prepare two-piece metal lids according to the manufacturer's directions. Screw bands 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 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. When preparing fruit for canning, choose one of the following treatments to prevent this natural occurrence:
- Place fruit in a solution of 1 teaspoon (3,000 milligrams) of powdered ascorbic acid (vitamin C) and 1 gallon water. Crushed vitamin C tablets also may be used. Drain fruit before proceeding.
- Use a commercial ascorbic acid mixture. These mixtures are available in the canning and produce sections of many stores. Prepare the mixture according to the package’s instructions. Drain fruit before proceeding.
- Place fruit into a solution of powdered citric acid and water. This may be less effective for controlling discoloration than other methods. Follow the manufacturer's directions. 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 options may be used to provide sweetness.
SUGAR SYRUP
Mix sugar with water and heat until the sugar dissolves; skim if necessary. Use proportions for the sweetness you desire. “Very light” is closest to canning fruit in its own juice. The ratios in Table 1 may be used as a guide to make 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, undamaged, juicy fruit. Heat to simmer (185–210 degrees Fahrenheit) over low heat. Strain through a jelly bag or cheesecloth.
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.
NON-NUTRITIVE SWEETENERS
While sweeteners provide a sweet taste to the fruit and canning liquid, they do not provide the other preservative effects of sugar. It is best to add non-nutritive sweeteners 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. Sucralose-based sweeteners may be added before canning but may leave an aftertaste. Sucralose-based sweeteners can also be sweeter than anticipated, so it is recommended to use a less than one-to-one substitution. Check labels for equivalents to the amount of sweet flavor desired.
Canning Juice
GRAPE JUICE
Choose fruit of good quality for eating fresh and cooking. Sweet, wellcolored, firm, mature fruit work well. An average of 24.5 pounds will produce 7 quarts; 16 pounds will produce 9 pints. Follow the juice-preparation directions in Table 2.
APPLE JUICE
Good quality apple juice is made from a blend of apple varieties. For best results, purchase fresh juice from a local cidermaker within 24 hours after it has been pressed. Follow the juice-preparation directions in Table 2.
Filling Jars
RAW PACK METHOD
Place raw, prepared fruit into jars and then cover with hot syrup, juice, or water. Pack tightly because raw fruit shrinks during processing. Raw-packed fruit is more likely to float. Check Table 2 for the correct amount of headspace to leave between the top of the fruit and the jar lid. Due to quality, some fruits are not recommended for raw packing.
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 Table 2 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 tool around the inside of the jar walls. If needed, add more liquid. Wipe the jar rim with a clean, dampened towel to remove any food particles. Place prepared lids on jars. Place metal screw bands on tops of jars and screw them down until they are fingertip tight. Avoid over-tightening.
Preparing the Canner
Fill the 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 until it is 1 to 2 inches over the jar tops. Cover the canner with the lid and turn the burner to the highest heat setting. Bring the water to a vigorous boil. Lower the heat setting to maintain a gentle boil and start timing—see Table 2 for specific processing times. Add boiling water as needed during the processing to keep the water level at least 1 inch above the jars. When processing is complete, turn off the heat, remove the lid, and let stand for 5 minutes. Use a jar lifter to remove jars. 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 screw bands or touch the lids until the jars have cooled. Allow the jars to cool undisturbed and away from drafts for 12 to 24 hours.
Checking Seals and Storage
Listen for the familiar "ping" as the jars cool. Look for the slight depression in the lid's center. When completely cooled, test for a proper seal by pushing down on the center of the lid; it should not pop up and down. Allow the canned foods to cool on the countertop before removing the screw ring bands. Jars should not be stored with the screw bands on. After removing the screw bands, push down on the center of the lids and wipe the jars with a clean, damp cloth to remove any residue or stickiness. Add labels with the date, batch, food product, and any other specific information. Store jars in a cool, dry, dark place.
Signs of Spoilage
If a jar does not seem normal before or after opening, do not consume the fruit. This includes leaking jars, bulging lids, and jars that spurt when opened. If the food looks spoiled, foams, or has an off odor, discard it.
|
|
For more information on food preservation, visit the Ohio State University Extension Food Preservation webpage.
Resources
For more information on food preservation, visit:
- National Center for Home Food Preservation:
nchfp.uga.edu - United States Department of Agriculture Complete Guide to Home Canning:
nchfp.uga.edu/resources/category/usda-guide
Originally written May 28, 2015 by Christine Kendle and Katherine Shumaker, Extension Educators, Family and Consumer Sciences, Ohio State University Extension.