On the whole, freezing fruits is less complicated and time-consuming than freezing vegetables. Fruits do not generally require a blanching/cooling/drying cycle before packaging for the freezer (apples are an exception, though this action is optional). However, there are several methods to choose from, depending on the fruit’s intended use when thawed, which involves planning and forethought. The fruit is prepared for freezing and then packed, either on its own or mixed with various solutions, usually involving sugar and/or ascorbic acid, before freezing.
Always select fully ripe, but firm, fruit. If the fruit is soft or mushy but still fresh-smelling and fresh-tasting, consider making a purée for freezing. Wash fruit (berries very gently), unless otherwise recommended, in cool or cold running water or lifting the fruit in and out of one or two changes of water. Do not soak fruit for very long as this will cause a loss of nutrients and flavor and can water log the fruit. Cut away or discard any parts that are green or of poor quality. Don’t let galvanized equipment come into direct contact with fruit-the acid in fruit dissolves the zinc, which is poisonous. Also, be wary of iron utensils or chipped enamel ware, as metallic off-flavors cans result. Prepare fruits as they will be used, stemmed, pitted, peeled, and/or sliced.
There are several ways to pack fruit for freezing. Sweetened fruit is accomplished with a syrup pack, sugar pack or sweetened pectin syrup pack. For unsweetened fruit, the options are dry pack, tray or loose pack, unsweetened pectin syrup pack, water or unsweetened juice pack, and purée or fruit juice pack. (The difference between the two “juice packs” will be clarified below.) Always leave some head space in whichever containers you use, including freezer bags, to allow for expansion. This is more crucial in rigid containers, especially glass canning jars. For dry pack, 1/2″ head space is usually sufficient, for any liquid pack, leave 1/2″ head space for a wide-mouth pint jar, 1″ for a wide-mouth quart jar, 3/4″ for a narrow- or regular-mouth pint jar, and 1 1/2″ for a narrow- or regular-mouth quart jar. Always leave 1 1/2″ head space for juice in whichever containers are used.
The type of pack is usually determined by the intended use. Fruits packed in syrup are generally best for uncooked desserts. Fruits packed in dry sugar or unsweetened can be used for uncooked or cooked recipes. If you plan to make jam or other sweet spreads from frozen fruit, leave the fruit unsweetened. You can add the correct amount of sweetener when making the jam. Don’t worry if there is an excess of liquid from the thawed fruit. Simply allow it to drain off and use it as part or all of the liquid required for any thickening required or use in other culinary endeavors.
A note here on using sugar solutions. Unsweetened fruits lose quality faster than sweetened fruits. Sugar helps fruit retain its flavor, color and texture, though sugar is not necessary to preserve fruit.
Some fruits need pretreatment to prevent darkening–peaches and apples for example. Ascorbic acid (vitamin C), citric acid, lemon juice and pineapple juice are all preventative options, though ascorbic acid is by far the most effective. Actually, ascorbic acid can be used with all fruits. Besides its color retention ability, it helps preserve flavor and adds some nutritive value as well. You can find powdered ascorbic acid in pharmacies, health food stores, the canning section of supermarkets and on-line. You can also crush vitamin C tablets (or take apart capsules), though these often contain fillers that, will not detrimental to the fruit, can make a cloudy solution. Instructions for using ascorbic acid solutions are given with the different fruits.
Sugar substitutes or artificial sweeteners provide sweetness but they do not function like sugar, which thickens syrups, preserves color and gives a firm texture. Research using stevia and xylitol is sparse and mostly anecdotal; xylitol is perhaps the closest alternative to sugar for freezing procedures. It’s best to freeze fruit first using an unsweetened pack and then adding the sugar alternate(s) when using the thawed fruit.
Syrup Pack: A syrup pack is made with sugar dissolved in water. The water can be cold, warm or hot. Sugar dissolves quickest in hot water, but the syrup must then be cooled before using. The proportion of sugar to water depends on the sweetness of the fruit. Lighter syrups are better for mild-flavored fruits, heavier for very sour fruits. Generally, a light syrup is 30% sugar to water, medium is 40% and heavy is 50%. Freezing guides recommend a 40% solution for most fruits, though check the individual listings for specifics.
Light Syrup: 30% – 2 1/4 c sugar + 5 1/4 c water = 6 1/2 c syrup
Medium Syrup: 40% – 3 c sugar + 5 c water = 6 c syrup
Heavy Syrup: 50% – 4 1/4 c s + 4 1/4 c water = 6 1/2 c syrup
Note that the percentages are approximate. In general, up to one fourth of the sugar may be replaced by mild-flavored honey or light corn syrup.
One-half to 3/4 of a cup of syrup is used for pints and 1 cup to 1 1/2c of syrup for quarts.
A small piece of crumpled freezer or other water-resistant paper can be used to hold down the fruit in the syrup, if necessary.
Sugar Pack: With this method, you sprinkle sugar over the fruits, generally 1/2 to 2/3 c of sugar per quart of fruit, though it’s really a matter of personal preference. Mix gently until the juice is drawn out and the sugar has dissolved. Soft, sliced fruit such as peaches, strawberries, plums, and cherries will yield sufficient syrup if the fruit is layered with sugar and allowed to stand for 15 minutes. Some small, whole fruits may be just coated with sugar and frozen.
Sweetened Pectin Syrup Pack: This pack differs from the unsweetened pectin syrup pack in that it is formulated with some sugar. This pack is recommended for strawberries and peaches most.
1 box powdered pectin + 1 – 2 c water + 1/2 sugar. Combine pectin and 1 c of water in a saucepan. Bring to the boil and boil 1 minute. Remove from heat and add sugar, stirring to dissolve. Carefully pour into a large measuring cup and add enough water to make 2 c of syrup. Chill before using.
Dry Pack: Wash fruit, dry, pack in container of choice, seal, and freeze. This is good for small, whole fruits that taste good without sugar.
Tray or Loose Pack: This is a dry, unsweetened pack that is good for small, whole fruits such as blueberries and raspberries. The fruit is easier to remove from the freezer container. Spread a single layer on shallow, rimmed trays and freeze. A layer of wax or parchment paper on the tray under the fruit will allow for easy transfer to the freezer container.When the fruit has frozen, usually in 1 – 2 hours, pack and seal. If the fruit is on the tray in the freezer for a long period, freezer burn can result, as well as moisture loss and a decrease in quality.
Unsweetened Pectin Syrup Pack: Though this is considered unsweetened, the powdered pectin may contain a small amount of sugar, usually dextrose. This method is often used for strawberries and peaches that retain their texture better than if frozen in water of juice.
1 box powdered pectin + 2 3/4 c water. Combine pectin and one cup water in a saucepan. Heat to boiling and boil one minute. Remove from heat and add remaining water. Makes about 3 c of moderately thick syrup. Add more water if a thinner syrup is desired. Chill before using. Coat fruit with a thin glaze of syrup only.
Only use enough to coat the fruit thinly-thoroughly, but thinly.
Water Or Unsweetened Juice Pack: These packs often yield a product that don’t have the plump texture and good color of those packed with sugar. The fruits take longer to freeze and longer to thaw. That being said, blueberries, raspberries, and steamed apple slices take well to this method. Just pack the container with fruit and cover with water or unsweetened fruit juice, leaving the appropriate head space.
Purée or Fruit JuicePack: Purée or juice fruit and pack as is. Sweetening is optional Adding ascorbic acid is a good idea. Use crumpled freezer or other water-resistant paper or plastic wrap on top to reduce surface moisture crystallization.