Recipes for canning fruit usually call for adding sugar or sugar syrup. However, all fruits can safely be canned or frozen without sugar. While sugar helps hold the texture, shape and color of fruit, it is primarily added for flavor. It is not needed to prevent spoilage. You can safely preserve all fruits in water or in fruit juice by following reliable canning directions for preparing and processing the fruit.
When canning without sugar, use high-quality fruit. Overripe fruit will soften excessively. Take special care to follow steps that prevent darkening of light-colored fruit. Several treatments may be used to prevent or retard darkening. One is to coat the fruit as it is cut with a solution of 1 teaspoon crystalline ascorbic acid or 3,000 mg crushed vitamin C tablets per cup of water. Another is to drop the cut pieces in a solution of water and ascorbic acid, citric acid or lemon juice. Use 1 teaspoon ascorbic or citric acid or 3/4 cup lemon juice to 1-gallon water.
An ascorbic acid/water solution serves as a desirable anti-darkening treatment, adds nutritive value in the form of vitamin C, and does not change the flavor of the fruit as lemon juice may do. Ascorbic acid is available in crystalline or tablet form in drug stores and supermarkets. Ascorbic acid mixtures, such as ascorbic acid combined with sugar or with citric acid and sugar, also are available. For these, follow the manufacturer’s directions.
For best results, prepare fruits to be canned without sugar using the hot-pack method. However, water or regular unsweetened fruit juices may be used instead of sugary syrup.
To prepare, bring thoroughly ripe, crushed fruit to a simmer over low heat. Strain through a clean jelly bag or cloth. Blends of unsweetened apple, pineapple and white grape juice also are good filling over solid fruit pieces.
If ascorbic acid products are not used in the pretreatment of cut fruit, they may be added to the canning juices or liquids before processing to help keep the fruit from darkening during storage. Use 1/4 to 1/2 teaspoon crystalline ascorbic acid or 750 to 1,500 mg crushed vitamin C tablets per quart of fruit. Commercial ascorbic and citric acid mixtures also may be used according to manufacturer’s directions.
Honey or light-colored corn syrup may be substituted for up to half the sugar called for in a canning syrup recipe. However, these products do not reduce the calorie or carbohydrate content of the sugar syrup, and thus are not acceptable sugar replacements for people on diabetic diets.
Substituting plain water for the sugar syrup reduces the calorie content of canned fruit by approximately 205, 280 or 375 calories per pint, assuming 2/3 cup of thin, medium or thick syrup, respectively, is replaced with water.
Adjust headspace and add lids. Process jars of fruit packed with water or fruit juice as for fruits packed with syrup. Use USDA recommended procedures and timetables that have been adjusted for altitude.
All fruits may be frozen without added sugar. Sugar is not needed for the preservation of frozen fruits, but it does help the fruit maintain quality longer.
Berries and fruits such as cherries, plums, dates, grapes, melon balls, pineapple chunks and rhubarb slices that do not darken when exposed to air are best frozen in single layers on trays, then packed into freezing bags or containers. These fruits may be served partially thawed, giving some juice, but with some frozen firmness still remaining in the fruit itself.
Light-colored fruits, such as apples, peaches and apricots, freeze well in unsweetened juice or water. Pack them in rigid containers, leaving 1/2 inch of headspace for square pint containers and 1 inch for quart containers. Retard darkening of light-colored fruits by one of the methods discussed in the section on canning fruit without sugar. Artificial sweeteners, if available, may be added to the water in an amount equal in sweetness to a sugar-sweetened syrup. Make a small batch to test for acceptability before freezing large quantities.
Canning Relishes and Pickles
Sweet relish and pickle recipes do not adapt as well to sugar-free canning as do plain fruits. Try recipes that call for artificial sweeteners, but don’t be too discouraged if some batches are disappointing. Finished products often are mushy or have an unsuitable flavor. When canning pickles and relishes, use the boiling water bath method and processing times that are adjusted for altitude.
(Sources: Ball Blue Book, Ball Corporation, Muncie, IN 47302; Colorado State University: http://www.ext.colostate.edu/pubs/foodnut/09302.html; So Easy To Preserve, S. Reynolds and P. Ybarra, 1983. Extension Service, University of Georgia, Athens; The Complete Guide to Home Canning. Agriculture Information Bulletin No. 539-1, U.S. Department of Agriculture Extension Service, revised 2009)
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