Frozen raw hamburger meat remains safe in the freezer indefinitely, but it is best if used within four months. Completely cooked hamburger meat that is frozen within two hours of cooking should be used within four months.
Hamburger meat can be frozen in its original packaging if it is to be used quickly, but it should be wrapped in plastic wrap, aluminum foil or freezer paper for long-term storage. Partially cooked hamburger meat should not be frozen because partially cooking it allows harmful bacteria to grow, which are not destroyed when the meat is defrosted and cooked again later.
Frozen hamburger should be thawed in the refrigerator, where it can be kept cold enough to prohibit the growth of harmful bacteria. It can also be thawed in the microwave or by wrapping it in a watertight plastic bag and soaking it in cold water, changing the water every 30 minutes. Hamburger meat thawed in the refrigerator can be refrozen within two days, whereas meat thawed in a microwave or in cold water cannot be refrozen.
Failure to follow safe food handling procedures, including guidelines for freezing and thawing hamburger meat, can lead to serious illnesses, especially for the young, the elderly and those with weakened immune systems.