What is the best method for freezing mushrooms?
Wash mushrooms and remove stem base. Freeze small mushrooms whole; cut large ones into 4 or more pieces. When blanching mushrooms, add 1 teaspoon citric acid, or 1 tablespoon lemon juice, or 1/2 teaspoon ascorbic acid per quart of water to prevent darkening. Blanch medium or small whole mushrooms 5 minutes; cut pieces, 3 minutes. Chill in ice water. Pack tightly in freezer bags or rigid containers. Squeeze as much air as possible from bags before sealing. Leave 1/2 inch headspace for expansion in containers. To blanch vegetables in boiling water, start counting blanching time as soon as the vegetable is placed in boiling water. Blanch no more than 1 pound of vegetables per gallon of boiling water at a time. Immerse wire basket or mesh bag with vegetables in boiling water. Cover and blanch for required time. Cool immediately in ice water for the same time as for blanching. Drain thoroughly.
