Michigan State University Extension
Preserving Food Safely - 01600293
Whole. Choose firm, ripe, red berries preferably with a slightly tart flavor. Large berries are better sliced or crushed. Sort berries, wash them in cold water, drain well and remove caps and stems.
Sugar and syrup packs make better quality frozen strawberries than berries packed without sweetening.
Syrup pack Put berries into containers and cover with cold 50-percent syrup (1 cup sugar to 1 cup water), leaving 1/2-inch headspace. Seal, label and freeze.
Sugar pack Add 1 part sugar to 6 parts strawberries and mix thoroughly. Put into containers, leaving 1/2-inch headspace. Seal, label and freeze.
Unsweetened pack Pack strawberries into containers, leaving 1/2-inch headspace. For better color, cover with water containing 1 teaspoon ascorbic acid to each quart of water. Seal, label and freeze.
Puree Prepare strawberries as for freezing whole. Then press berries through a sieve. To 1 pint puree add 4 tablespoons sugar and 1 teaspoon lemon juice; mix well. Put into containers, leaving 1/2-inch headspace. Place a disc made from plastic over the top of puree to prevent discoloration. Seal, label and freeze.