How to freeze fruit for best quality

It’s harvest time in Ohio for fresh fruit, and for those of us who grow our own fruit, that might be more than we can enjoy in its short shelf life window. Sharing with friends and family is an option. Freezing and storing extra fruit to use up over time is another.

Freezing fruit is an easy way to preserve fruit so it retains its nutritional quality.

ensure success

Although the nutritional value of fruit is preserved when frozen, its colour, texture and flavor can be affected by enzyme activity, air, microorganisms, ice crystal formation and the rate of moisture evaporation.

enzyme activity. Enzymes occur naturally in fruit and regulate the ripening process. Freezing fruit slows this process, but doesn’t stop it. Ascorbic acid can be used to control enzyme activity and prevent browning when freezing fruit.

Air. Exposure to air can increase enzymatic reactions and oxidation causing surface browning. It can also increase moisture loss. Make sure the air is removed and the package is tightly sealed before freezing fruit.

microorganisms. Bacteria, mold and yeast are present in all fresh food and multiply rapidly when the temperature is between 40 F and 140 F. Freezing controls the growth of microorganisms; However, survivors can grow again if food is thawed. That’s why it’s important to freeze and thaw fruit properly.

ice crystals. Small ice crystals are desirable as the texture of the fruit is preserved much better. Large crystals damage food cells and create a soft, squishy texture. You can ensure the formation of small crystals by freezing food quickly and evenly. Fruits with high moisture content such as berries and grapes can be frozen individually on baking sheets for 4-6 hours and then placed in storage containers. For fruit that is already in containers, make sure there is enough clearance in your freezer to allow cold air to circulate from all sides. Do not overload your freezer and place the food you are freezing between the food that is already frozen for efficient freezing.

evaporation of moisture. Reducing the amount of moisture evaporating from fruit while it’s in the freezer means packing it properly. The loss of moisture exposes the fruit to oxygen, resulting in a loss of colour, flavor and texture. Containers and freezer bags should be emptied of as much air as possible and allow the proper headspace before sealing.

headspace

• Fruit packed in juice, sugar, syrup, or water, as well as chopped and pureed fruit, should have ½-¾ inches of space for pint containers and 1-1 ½ inches of space for quart containers. It’s important to leave enough room for the liquid to expand so the juices don’t overflow your containers as they freeze. Place a piece of plastic wrap over the fruit to keep it submerged in the syrup or liquid.
• Fruit packaged without sugar or liquid should have a ½ inch headspace.

Packing with sugar or syrup

Fruit can be frozen without sugar, but it freezes harder and takes longer to thaw. Sugar helps keep frozen fruit firm and prevents browning.

Sugar. Fruits destined for cakes and other baked goods are often packed in sugar. One cup of sugar should be used for every 2-3 pounds of fruit. Juice forms when the fruit sits in the sugar. When using sugar-filled fruit in baking recipes, the relative amount of sugar should be factored into the total sugar required for the recipe.

syrup. Fruit that you preserve to serve uncooked can be packed in a syrup of sugar and water. Honey and maple syrup can replace some of the sugar, but may affect the flavor of the end product. Use about ½ to ⅔ cup of syrup for every pint of fruit and 1 ⅓ cup for every quart of fruit. Make sure the fruit is covered in syrup before storing. Allow the syrup to cool before pouring it over the fruit.

• Very Light Syrup: 4 cups water, ½ cup sugar
• Light syrup: 4 cups water, 1 cup sugar
• Medium syrup: 4 cups water, 1 ¾ cups sugar
• Heavy Syrup: 4 cups water, 2 ¾ cups sugar
• Very Heavy Syrup: 4 cups water, 4 cups sugar

Other options. Water, fruit juice, and pectin syrup can also be used to freeze fruit, but they don’t have all the benefits of freezing fruit with sugar or syrup. Juice has some of the benefits of freezing fruit with sugar, and pectin power can be used to improve the freezing quality of fruit that has poor texture when frozen.

Freezing Tips

• Choose fruits that freeze well. Apples, blackberries, blueberries, cantaloupes, grapes, peaches, pears and plums are all in season in Ohio right now.
• Prepare only a few containers for freezing at a time, so that fruit can be frozen quickly and evenly after packing and sealing.
• Before packing, wash the fruit to remove dirt, but do not soak the fruit in water.
• Do not use galvanized copper or iron utensils to prepare fruit for freezing. The acid contained in fruit can react with the metals and form harmful compounds or change the taste of the fruit.
• Before freezing, remove green and bruised areas from fruit.
• Pre-treat fruit to prevent browning by adding ascorbic acid to holding water to prevent browning. Use 1 teaspoon (3,000 milligrams) per gallon of water. Drain the fruit before sweetening or packaging.
• Ascorbic acid may also be added to individual packages of fruit at a rate of ½ teaspoon per liter of cold syrup, or ½ teaspoon in 3 tablespoons of cold water for every 4 cups of fruit intended to be stored without syrup.
• Chill fruit in the refrigerator before packaging.
• Freeze fruit in portions that can be thawed and used for a single meal or portion.
• Choose moisture and steam resistant packaging materials; durable and leakproof; resistant to cracking and brittleness at low temperatures; resistant to oil, grease and water; impervious to the absorption of smacks and odors; easy to close and label. Some recommendations for fruit packaged without sugar or liquid include plastic freezer bags, vacuum freezer packs, rigid plastic containers, and glass or plastic freezer jars. Recommendations for fruit packaged with added sugar or liquid include rigid plastic containers and glass or plastic freezer jars.
• Don’t use paper cartons, food containers made from recycled plastic, flimsy plastic, or containers with cracks or ill-fitting lids.
• Label packaged fruit with the type of fruit, ingredients added, packaging date, number of servings, and use-by date. Frozen fruit should be used within 8 to 12 months of freezing to get the best quality.
• Freeze fruit as soon as it’s wrapped and sealed. Otherwise, refrigerate it until you can. The sooner fruit is frozen efficiently, the better its quality will be preserved in the freezer.
• Do not overload the freezer. Leave enough space for air circulation to make fruit freeze quickly.
• Thaw fruit in the refrigerator, under cold running water, or in the microwave to use immediately.

resources

Penn State Extension