University of Missouri Extension

GH1502, Reviewed November 2011

Quality for Keeps: Freezing Fruits

Reviewed by the Food Preservation Team
Human Environmental Sciences Extension

Frozen foods can add variety to your meals year-round. As with any method of food preservation, following specific guidelines will assure you of high quality, safe food.

Tips for successful freezing

Table 1
Approximate yield of frozen fruits from fresh

Fruit Fresh, as purchased or picked Frozen pints
Apples 1 bushel (48 pounds)
1-1/4 to 1-1/2 pounds
32 to 40
1
Apricots 1 bushel (48 pounds)
2/3 to 4/5 pound
60 to 72
1
Blackberries, blueberries, boysenberries, dewberries, elderberries, gooseberries, huckleberries, loganberries and youngberries. 1 crate (24 quarts)
1-1/3 to 1-1/2 pints
32 to 36
1
Cantaloupes 1 dozen (28 pounds)
1 to 1-1/4 pounds
22
1
Cherries, sweet or sour 1 bushel (56 pounds)
1-1/4 to 1-1/2 pounds
36 to 44
1
Cranberries 1 box (25 pounds)
1/2 pound
50
1
Grapes 1 bushel (48 pounds)
2 pounds
20 to 24
1
Peaches 1 bushel (48 pounds)
1 to 1-1/2 pounds
32 to 48
1
Pears 1 bushel (50 pounds)
1 to 1-1/4 pounds
40 to 50
1
Pineapple 5 pounds 4
Plums* 1 bushel (50 pounds**)
1 to 1-1/2 pounds
34 to 50
1
Raspberries 1 crate (24 pints)
1 pint
24
1
Rhubarb 15 pounds
2/3 to 1 pound
15 to 22
1
Strawberries 1 crate (24 quarts)
2/3 quart
38
1
*Includes blackberries, blueberries, boysenberries, dewberries, elderberries, gooseberries, huckleberries, loganberries and youngberries.
**As defined by Missouri Department of Agriculture.

Preventing darkening

Fruits like peaches, apples, pears and apricots darken quickly when exposed to air and during freezing. They also may lose flavor when thawed. There are several ways to prevent darkening and flavor loss in frozen fruit.

Crystalline (powdered) ascorbic acid, or vitamin C, is the most effective agent in preventing darkening of fruit. Not only does it preserve natural color and flavor of fruits, but it adds nutritive value as well. Ascorbic acid in crystalline or powdered form is available at some drugstores or where freezing supplies are sold. Check in advance as it may have to be special ordered.

Ascorbic acid tablets are more readily available and less expensive, but are more difficult to dissolve. Also, fillers in the tablets may make the syrup cloudy. Three thousand milligrams of ascorbic acid in tablet form equal one teaspoon of crystalline ascorbic acid. To use, dissolve ascorbic acid in a little cold water. If using tablets, crush them so they will dissolve more easily. Use the amount specified for each fruit.

How to use ascorbic acid with different freezing methods

Commercial ascorbic acid mixtures are special anti-darkening preparations, usually made of ascorbic acid mixed with sugar or with sugar and citric acid. The important active ingredient in these mixtures usually is ascorbic acid. Follow manufacturer's directions for use. Do not confuse these mixtures with the ascorbic acid specified in directions for individual fruits found in this publication.

Citric acid or lemon juice are sometimes used in place of ascorbic acid. Neither, however, is as effective as ascorbic acid. When used in quantities high enough to prevent darkening, they often mask natural fruit flavors and make a tart-tasting product. To use, dissolve 1/4 teaspoon crystalline citric acid or 3 tablespoons of lemon juice in a quart of cold water. Place prepared fruit in the mixture for 1 to 2 minutes. Drain and pack the fruit.

Steaming works best for fruits that will be cooked before use. Steam the fruit in single layers over boiling water just until hot.

Sugar syrups work during preparation by excluding air from the fruit. Slice fruit directly into the syrup, and then use the same syrup for packing the fruit. To make this as effective as other methods, add ascorbic acid to the syrup.

Types of packs

There are several ways to pack fruits for freezing: syrup pack, sugar pack, unsweetened pack, tray pack and artificial sweetener pack. Whichever method you choose, be sure to leave the appropriate headspace (Table 2).

Table 2
Headspace for wide-mouth rigid containers

Type of pack Pint Quart
Liquid pack (Fruit packed in juice, sugar, syrup or water; crushed or pureed fruit and freezer jams) 1/2 inch 1 inch
Dry pack (Fruits packed without added sugar or liquid)*** 1/2 inch 1/2 inch
Fruit juice 1-1/2 inches 1-1/2 inches
***Tray-packed fruits do not need any headspace.

Caution
Do not use narrow-mouth jars for freezing foods packed in liquid, as expansion of the liquid could cause the jars to break at the neck

How you plan to use the fruit determines the type of pack:

Intended use Type of pack
Uncooked desserts Syrup
Cooking purposes (pies, crisps) Dry sugar/dry unsweetened
Sweet spreads Unsweetened (so that correct amount of sweetening can be added at time of preparation)

Syrup pack

The sweetness of the fruit to be frozen depends upon the proportion of sugar to water used. A 40 percent syrup is recommended for most fruits. Lighter syrups are desirable for mild-flavored fruits to prevent masking the flavors. Heavier syrups may be needed for very sour fruits. See Table 3 for proportions of sugar and water to use for the different syrups. To make the syrup, dissolve sugar in lukewarm water, mix until the solution is clear. Chill syrup before using

Use just enough cold syrup to cover the prepared fruit after it has been placed in the container (about 1/2 to 2/3 cup of syrup per pint). Leave appropriate headspace (Table 2). To keep fruit under the syrup, place a small piece of crumpled, water-resistant paper, such as waxed paper, on top of the fruit and gently press fruit down into the syrup. Seal container tightly, label and freeze.

Table 3
Syrups for use in freezing fruits

Type of syrup Sugar (cups)**** Water (cups) Yield of syrup (cups)
20 percent (very light) 1-1/4 4 4-2/3
30 percent (light) 2 4 5
40 percent (medium) 3 4 5-1/2
50 percent (heavy) 4-3/4 4 6-1/2
60 percent (very heavy) 7 4 7-3/4
****In general, up to one-fourth of the sugar may be replaced by corn syrup or a mild-flavored honey. A larger proportion of corn syrup may be used if a very bland, light-colored type is selected.

Sugar pack

Sprinkle sugar over fruit and mix gently until the juice is drawn out and the sugar dissolved. Soft-sliced fruits such as peaches, strawberries, grapes, plums and cherries will yield sufficient syrup for covering if the fruit is layered with sugar and allowed to stand 15 minutes. Pack into containers, leaving appropriate headspace (Table 2). To keep fruit under the syrup, place a small piece of crumpled, water-resistant paper, such as waxed paper, on top of the fruit and gently press fruit down into the syrup. Seal container tightly, label and freeze.

Unsweetened pack

Most fruits have a better texture, color and flavor if packed in sugar or syrup. However, sugar is not necessary to safely preserve fruit. For those wishing to cut down on sugar, fruit can be packed dry without any sugar, or covered with water or unsweetened juice containing ascorbic acid. For a juice pack, use unsweetened, light-colored, complementary juices such as apple, pineapple, orange or white grape juice. For all unsweetened packs, leave appropriate headspace (Table 2). When fruit is packed in unsweetened water or juice, keep fruit submerged by placing a small piece of crumpled, water-resistant paper, such as waxed paper, on top of the fruit and gently press fruit down into the juice or water. Seal container tightly, label and freeze.

Raspberries, blueberries, blanched apples, gooseberries, cranberries and rhubarb can be frozen without sugar and still be a good quality product.

Tray pack

The tray pack is a dry unsweetened pack that is good for small, whole fruits such as blueberries, raspberries and cranberries that give a good quality product without sugar. Spread a single layer of prepared fruit on shallow trays and freeze. Leave in the freezer just long enough to freeze firm. Longer exposure to dry freezer air will result in moisture loss and a decrease in quality. When frozen, promptly package, leaving no headspace, seal tightly, label and return to the freezer. The fruit pieces remain loose and can be poured from the container and the package reclosed.

Puree pack

Puree fruit and add ascorbic acid. Sweetening is optional. Pack, leaving appropriate headspace (Table 2), seal container tightly, label and freeze.

Artificial sweetener pack

Sugar substitutes work well in frozen fruit. They can be used in any of the unsweetened or dry packs, or they can be added to the fruits just before serving.

Artificial sweeteners give a sweet flavor but do not provide the beneficial preservation effects of sugar, such as color protection or thickness of syrup. The label on a sweetener package will tell you how much sweetener is equivalent to standard amounts of sugar. Use the label directions to determine the amount needed.

Thawing and using

Fruit is best served while it is still partially frozen with a few ice crystals still remaining. If thawed completely, frozen fruit will become mushy because of cell wall damage from ice crystals that form during the freezing process. Thaw fruit in the refrigerator, in the container you froze it in, about 12 hours per pint. For a shorter thawing time, run cold water over container until thawed. Thaw only enough fruit for one meal. Serve the juice from frozen fruit, too, as it is flavorful and contains nutrients.

Tips

Freezing instructions for specific fruits

Apples

When you plan to use apples in uncooked desserts or fruit cocktail, the syrup-pack method is preferred. A sugar or unsweetened pack is good for pie making. Select full-flavored apples that are crisp and firm, not mealy in texture. Wash, peel and core. Slice medium apples into twelve sections, large ones into sixteen.

Applesauce

Select full-flavored apples. Wash apples, peel if desired, core and slice. To each quart of apple slices, add 1/3 cup water or apple juice; cook until tender. Cool and strain if desired. Sweetening can be added if needed: 1/4 to 3/4 cup sugar for each quart of sauce. Or, use your regular recipe for applesauce.

Pack into containers, leave headspace, seal and freeze.

Apricots

Select firm, ripe, uniformly yellow apricots. Sort, wash, halve and pit. Peel and slice if desired. If apricots are not peeled, heat them in boiling water 30 seconds to keep skins from toughening during freezing. Cool in cold water and drain.

Dissolve crystalline ascorbic acid in cold water and sprinkle over 1 quart (7/8 pound) of fruit. Mix 1/2 cup sugar with each quart of fruit. Stir until sugar is dissolved. Pack apricots into containers and press down until fruit is covered with juice, leave headspace, seal and freeze.

Avocados

Select avocados that yield to gentle pressure with skins free from dark blemishes. Avocados are best frozen as puree. Avocados are not satisfactory frozen whole or sliced.

Bananas

Select firm, ripe bananas. Peel; mash thoroughly. Add 1 tablespoon lemon juice or 1/2 teaspoon ascorbic acid per cup of mashed banana. Pack into containers, leave headspace, seal and freeze.

Blackberries, boysenberries, dewberries, loganberries, youngberries

Select fully ripe, firm berries. Wash carefully in cold water, discarding soft, underripe or defective fruit, leaves and stems. Drain.

Blueberries

Select full-flavored, ripe berries. Wash berries and remove leaves, stems and immature or defective berries. Preheating in steam tenderizes skin and improves the flavor of the product.

Cherries, sour

Select bright red, tree-ripened cherries. Wash, stem and pit.

Cherries, sweet

Select bright, fully ripened cherries of dark colored varieties. Wash, stem and pit.

Gooseberries

Choose fully ripe berries if freezing for pie; choose berries a little underripe for jelly. Sort, remove stems and blossom ends and wash. The unsweetened pack is best for use in pies or preserves.

Grapes

Choose fully-ripe, firm, sweet grapes. Sort, stem and wash. Leave seedless grapes whole; cut table grapes with seeds in half and remove seeds.

Melons (cantaloupe, crenshaw, honeydew or watermelon)

Select firm-fleshed, well-colored, ripe melons. Cut in half, remove seeds and rind. Cut melons into slices, cubes or balls.

Peaches or nectarines

Select well-ripened fruit and handle carefully to avoid bruising. Sort, wash and peel. Note: peeling without a boiling water dip gives a better product. Slice or halve if desired.

Dissolve crystalline ascorbic acid in cold water and sprinkle over 1 quart (1-1/3 pounds) of fruit. Mix 2/3 cup sugar with each quart of fruit. Stir until sugar is dissolved. Pack into containers, leave headspace, seal and freeze.

Pears

Select full-flavored pears that are crisp and firm, not mealy in texture. Wash, peel and core. Slice medium pears into twelve sections, large ones into sixteen.

Persimmons

Select orange-colored, soft-ripe persimmons. Sort, wash, peel and cut into sections. Press fruit through a sieve to make a puree. For a better product, add 1/8 teaspoon crystalline ascorbic acid or 1-1/2 teaspoons crystalline citric acid to each quart of puree. Puree made from native (Missouri) varieties needs no sugar. Puree made from cultivated varieties may be packed with or without sugar.

Pineapple

Select firm, ripe pineapple with full flavor and aroma. Pare and remove core and eyes. Slice, dice, crush or cut the pineapple into wedges or sticks.

Note
If you plan to use frozen pineapple in gelatin desserts, bring it to a boil and simmer 2 to 3 minutes and cool before freezing. Raw pineapple, either fresh or frozen, contains an enzyme that prevents a gel from forming. Heating the pineapple before freezing will prevent this problem.

Plums

Select firm, ripe fruit soft enough to yield to slight pressure. Sort and wash. Leave whole or cut in halves or quarters and pit.

To prepare puree from heated fruit, add 1 cup water for each 4 quarts (4 pounds) of fruit. Bring to a boil, cook two minutes, cool and press through a sieve. Mix 1/2 to 1 cup sugar, depending on tartness of fruit, to each quart (2 pounds) or puree. Pack into containers, leave headspace, seal and freeze.

Raspberries

Harvest fully ripe, firm, well-colored berries. Remove those that are immature or defective. Wash and drain.

Strawberries

Select fully ripe, firm berries with a deep red color. Discard immature and defective fruit. Wash, drain and remove caps. Sugar and syrup packs produce a better quality product than unsweetened strawberries.

Original authors: Barbara J. Willenberg and Karla Vollmar Hughes.

GH1502, reviewed November 2011

GH1502 Quality for Keeps: Freezing Fruits | University of Missouri Extension

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