Most dairy products can safely be frozen, although it's important to note that the texture or appearance may change after freezing. If you want to freeze milk or other dairy products in liquid form, make sure to leave at least a half-inch of space in your airtight storage container, as the liquid will expand when frozen. Freezing shredded cheese often yields better results than freezing a block of cheese. When you're ready to use the frozen dairy products, allow them to defrost in the refrigerator before use. Since the texture may have changed, you may want to use them as ingredients when cooking rather than consuming defrosted dairy products as is. Dairy products are perishable by nature, so you should store them at 40 degrees Fahrenheit or below. If you leave dairy products out by mistake, you should throw them away after they are out for two hours (or one hour in 90 degrees Fahrenheit or warmer).