Freezing whole or skim milk is a way to preserve milk that may otherwise go to waste. Keep frozen milk in the freezer until you are ready to use it for cooking and baking. Thaw it in the refrigerator and give it a shake or stir to counteract the separation that takes place during the freezing process. Use it just like fresh milk in recipes that call for it.
Freeze milk in freezer-safe glass jars or in freezer-safe plastic containers. Like water, milk expands when it freezes, so you will need to leave head space in the jar or container for the milk to expand into. You can freeze milk in wide-mouth pint jars, leaving about 1/2 inch of head space for the milk to expand or in wide-mouth quart jars, leaving 1 inch of head space. If you are freezing the milk in narrow mouth, also called regular, jars, leave 1 1/2 inches of head space for both size jars. Milk can remain frozen for up to 3 months.