Can you freeze milk in its plastic container?

Yes, milk can be frozen. Freeze it in plastic freezer contrainers and leave 1/2- to 1-inch headspace to give the milk room to expand as it freezes. You shouldn't freeze milk for longer than one month. Thaw it in the refrigerator and stir well before using. Milk that has been frozen is best to use for cooking as it may be slightly grainy when it's thawed. But there's no harm in drinking it at all.