Freezing fruits is simple and easy. Freezing costs more than canning or drying but preserves more nutrients and a fresher flavor, if done properly.
Freezing does not completely destroy bacteria, molds, and yeasts, but it does retard their growth. As soon as food is thawed, microorganisms may continue to grow.
Natural enzymes in fruits cause flavor, color, texture, and nutritive value changes. Freezing slows enzyme activity but does not stop it. You can prevent enzyme browning in light-colored fruits by treating them with ascorbic acid and other commercial products.
Selecting and Washing
Fully ripe fresh fruits lose quality rapidly after harvesting. Harvest only an amount you can preserve within a few hours; otherwise, refrigerate, then freeze as soon as possible.
Choose fully ripe, but firm, fruit. Underripe fruits may be bitter. Freeze soft, very ripe fruits as purees.
To thoroughly remove dirt, bacteria, and pesticide residue, wash all fruits in cold water. Drain and rinse several times with cold water. Lift fruits from water to prevent redepositing of dirt and residues. Do not let fruits soak.
Packaging
Air leads to flavor loss or off flavors. If moisture evaporates, frozen food becomes dry, tough, and may develop grayish spots called "freezer burn." To prevent air exposure and moisture loss, use only moisture-proof, vapor-proof packaging designed for freezing. Examples are "can or freeze" glass jars, plastic freezing containers, heavyweight aluminum foil, plastic-coated freezer paper, and polyethylene wraps and bags. Only sealing tape designated for freezer use will adhere at freezing temperatures. Place freezer bags in rigid containers for easy stacking.
Pack fruit and syrup tightly in freezer bags or rigid containers. Squeeze air from bags before sealing. Leave 1/2-inch headspace for expansion in rigid containers. Whole berries may be frozen in a single layer on a tray until nearly solid. Package at once. Label and date product and return it to freezer.
Freezing
Because water in fruits expands during freezing and breaks cell walls, thawed fruits may leak juices and be soft. To retain quality, freeze fruits quickly at lowest possible freezer setting. Freeze only 2 to 3 pounds of food per cubic foot of available storage space in 24 hours.
Storing
Maintain freezer at 0 degrees Fahrenheit (F) or less. If power fails, keep freezer closed; food should stay frozen 24 to 48 hours. If available, protect food with 25 pounds of dry ice per 10 cubic feet of freezer space. Food can safely be refrozen if it still contains ice crystals. Some loss of quality and food value will occur.
Keep an inventory and use oldest foods first. The more food you put into your freezer in a year, the less the operating cost per pound. Use frozen fruits within one year. Citrus fruit and juices should be used within 6 months.
Preparing
Defrost fruit in its original package in one of these ways: at room temperature in a pan of cool water, in a microwave oven, or in the refrigerator. Serve fruit with a few ice crystals still remaining. Completely thawed fruits will be limp or mushy and may discolor.
Directions for Freezing Fruit
Wash and sort fruit. Discard poor quality pieces. Work with small quantities. Pare and remove pits, seeds, and blemishes. Leave whole, slice, or puree (see chart or directions for individual fruits).
Treat washed and sorted fruit with ascorbic acid (available at drugstores, 1 teaspoon = 3 grams) or some other treatment to prevent discoloration of fruits, particularly apples, peaches, and nectarines. Add crystalline ascorbic acid to chilled syrup just before using or follow manufacturer's directions if using other anti-darkening products.
Pack with sugar or syrup or leave unsweetened (dry). Unsweetened fruits lose quality faster than sweetened fruits. Sugar helps fruit retain its flavor, color, and texture, but is not necessary to preserve fruit safely. Artificial sweetener can also be added to fruit prior to freezing.
Types of Pack
Sugar pack--Sprinkle sugar over the fruit and mix gently. Allow to stand for 10-15 minutes to draw out juice, which will dissolve sugar, or freeze immediately.
Syrup pack--Dissolve sugar in lukewarm water until the solution is clear. Cool, then add ascorbic acid and just enough syrup to cover fruit (about 1/2 to 2/3 cup per pint). To keep fruit under syrup, place a small crumpled piece of plastic or freezer wrap on top and press fruit down into syrup before sealing the container. One-fourth of the sugar may be replaced by light corn syrup or mild-flavored honey.
Dry pack--Pack fruit in container, seal, and freeze. Good for small whole fruits that taste good without sugar.
Tray pack--Spread a single layer of fruit on shallow trays and freeze. When frozen, package promptly and return to freezer. This pack allows portions to be used when needed.
Other unsweetened packs--Unsweetened fruit may also be packed in water, unsweetened juice, or pectin syrup. (To make pectin syrup, dissolve 1 package powdered pectin in 1 cup water, heat to boiling, and boil for 1 minute. Add 1 3/4 cup water and cool.) To keep the fruit under liquid, follow directions for syrup pack.
Artificial sweeteners--Sugar substitutes can be used in any of the unsweetened or dry packs or they can be added to the fruits before serving. However, sugar substitutes do not offer the beneficial effects of sugar (color protection and thickness of syrup).
References
Ball Blue Book (Vol. 1). (1995). Ball/Alltrista Corporation, Muncie, Indiana.
How to Freeze Food the Right Way. Gerald D. Kuhn and Anne V. A. Resurricion. Cooperative Extension Service, The Pennsylvania State University.
Preserving Food Safely (Version 3.0). Home Economics Library Program, Cooperative Extension Service, Michigan State University.
Putting Food By (Fourth Ed.). Janet Green, Ruth Hertzberg, Beatrice Vaughn, The Stephen Greene Press, Lexington, Massachusetts.
So Easy to Preserve (Third Ed.) (1993). Cooperative Extension Service, The University of Georgia.
Compiled by Sharon L. Mader, County Extension Agent, Family and Consumer Sciences/4-H, Sandusky County
Revised by Pat Shenberger, Ashland County
Syrups for use in freezing fruits
Type of syrup Percent syrup* Cups of sugar** Cups of water Yield of syrup in cups
Very Light 10 1/2 4 4 1/2
Light 20 1 4 4 3/4
Medium 30 1 3/4 4 5
Heavy 40 2 3/4 4 5 1/3
Very Heavy 50 4 4 6
* Approximate
** In general, up to one-fourth of the sugar may be replaced by corn syrup or mild-flavored honey. A large proportion of corn syrup may be used if a very bland, light-colored type is selected.
How to prepare fruits for freezing
Fruits Preparation
Apples Peel, core, and slice.
Syrup pack--Use 30-40 percent syrup; add 1/2 teaspoon (1500 mg.) ascorbic acid per quart of syrup. Slice apples into syrup in container, seal, and freeze.
Sugar pack--To prevent darkening, dissolve 1/2 teaspoon (1500 mg.) ascorbic acid in 3 Tablespoons water, sprinkle over fruit or steam blanch 1 1/2-2 minutes. Mix 1/2 cup sugar to 4 cups frui t. Seal and freeze. Dry and tray pack can be used.
Apricots Wash, halve, and pit. Peel and slice if desired. If not peeled, heat in boiling water 1/2 minute to keep skins from toughening during freezing. Cool in cold water and drain.
Syrup pack--Use 40 percent syrup and add 3/4 teaspoon (2250 mg.) ascorbic acid per quart of syrup.
Sugar pack--Pretreat fruit; dissolve 1/4 teaspoon (750 mg.) ascorbic acid in 3 Tablespoons cold water; sprinkle over 4 cups fruit. Mix 1/2 cup sugar per quart of fruit and stir until dissolved. Pack, seal, and freeze.
Bananas Peel and mash thoroughly. Add 1/2 teaspoon (1500 mg.) ascorbic acid or lemon juice per cup of mashed banana. Package, seal, and freeze.
Blueberries For dry pack, do not wash (washing results in a tougher-skinned product). Pack berries into container or freeze on a tray, then package. Wash before using. For sugar pack, wash first, then mix 2/3 cup sugar to 4 cups berries.
Cherries, red sour Wash, stem, and pit.
Syrup pack--Use 50 percent cold syrup, seal, and freeze.
Sugar pack--Mix 3/4 cup sugar to 4 cups cherries, then seal and freeze. Can use dry or unsweetened pack.
Cherries, sweet Wash, stem, and pit.
Syrup pack--Use 30-40 percent syrup with 1/2 teaspoon ascorbic acid to each quart syrup. Seal and freeze. Dry or unsweetened pack may be used.
Cranberries Pack without sugar in containers or freeze fruit on a tray. A 50 percent syrup may be used.
Grapes Sort, stem, and wash. Leave seedless grapes whole; cut grapes with seeds in half and remove seeds.
Syrup pack--Cover with 40 percent cold syrup, seal, and freeze.
Juice--Crush grapes. Add 1 cup water per gallon of grapes. Simmer for 10 minutes, then strain through a jelly bag. Let set overnight in refrigerator to remove tartrate crystals. Pour off clear juice for freezing and discard sediment. Seal and freeze.
Melons (cantaloupe, honeydew, or watermelon) Peel and remove seeds, then cut melons into slices, cubes, or balls.
Syrup pack--Put in containers and add 30 percent cold syrup. Seal and freeze.
Unsweetened--Pack into containers, seal, and freeze.
Peaches, nectarines Wash and peel.
Syrup pack--Use 40 percent syrup and add 1/2 teaspoon (1500 mg.) ascorbic acid per quart of syrup. Slice peaches directly into cold syrup in containers, press fruit down and add syrup to cover.
Sugar pack--Mix 2/3 cup sugar to 4 cups fruit. To retard darkening, sprinkle ascorbic acid solution (1/4 teaspoon in 3 Tablespoons cold water) to each quart fruit.
Plums, prunes Wash, halve, or quarter and pit.
Syrup pack--Cover with 40-50 percent cold syrup. Add 1/2 teaspoon (1500 mg.) ascorbic acid to each quart syrup. Seal and freeze.
Rhubarb Wash, trim, and cut into 1-inch lengths. Heating rhubarb in boiling water 1 minute, then cooling promptly in cool water helps retain color and flavor.
Dry pack--Pack tightly into containers without sugar, seal, and freeze.
Syrup pack--Pack into containers and cover with 40 percent cold syrup, seal, and freeze.
Strawberries Wash and remove caps.
Syrup pack--Cover berries in container with a cold 50 percent syrup, seal, and freeze.
Sugar pack--Mix 3/4 cup sugar to 4 cups berries, stir and let stand 15 minutes. Pack, seal, and freeze. May use dry or tray pack to freeze for unsweetened berries.
2006-09-02 12:16:51
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answer #5
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answered by Anonymous
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