To freeze food is to lower its temperature until most of its water content turns to ice, which slows or stops the microbial and enzymatic activity that causes spoilage. It is the everyday verb for the preservation technique described more fully under freezing, and covers everything from freezing raw ingredients like meat and vegetables to freezing fully cooked dishes for later reheating. Proper freezing depends on airtight packaging and a consistent storage temperature at or below 0°F (-18°C); improper freezing leads to freezer burn and texture loss on thawing.