Michigan State University Extension
Preserving Food Safely - 01600314
Whole Syrup pack is preferred for berries to be served uncooked. Sugar pack or unsweetened pack is satisfactory for berries to be used for cooked products such as pie or jam.
Select firm, plump, fully ripe berries with glossy skins. Green berries may cause off-flavor. Sort and remove any leaves and stems. Wash and drain.
Use one of the following packs:
Syrup pack Pack berries into containers and cover with cold 50- percent syrup (1 cup sugar to 1 cup water). Seal, label and freeze.
Sugar pack To 1 quart (1 1/3 pounds) berries, add 3/4 cup sugar. Turn berries over and over until most of the sugar is dissolved. Fill containers. Seal, label and freeze.
Unsweetened pack Pack berries into containers. Seal, label and freeze.
Crushed or puree Prepare for packing in same way as for whole berries. Crush or press through a sieve for puree. To each quart (2 pounds) of crushed berries or puree add 1 cup sugar. Stir until sugar is dissolved. Pack into containers. Seal, label and freeze.