Freeze prepared food as quickly as possible, and thaw frozen food in one of only three ways: in cold water, in the refrigerator or in warm water. Maintaining a freezer temperature of 0 F or lower is one key way to keep food safe. Dangerous bacteria can grow on food that isn't frozen properly.
It is possible to test a freezer's temperature using a thermometer. In a freezer without a thermometer, ice cream is a good indicator of the temperature: ice cream remains rock hard in a freezer that is adequately cold but stays soft in a freezer that is too warm.
Never thaw frozen foods at room temperature. Many foods thaw overnight in the refrigerator, though large items can take a few days to thaw completely. A quicker option is to seal the food in a leak-proof bag and submerge the item in a bowl of cold water. Change the water every 30 minutes until the item is thawed, then cook it, and eat it right away. The fastest way to thaw something frozen is to use the microwave's defrost function.
Frozen foods that are stored properly should remain safe indefinitely. However, frozen items lose flavor, texture and nutritional value after a period of time.