Safe Defrosting There are three safe ways to defrost meat: in the refrigerator, in cold water, and in the microwave. Never defrost on the counter or in other locations. Refrigerator: It’s best to plan ahead for slow, safe thawing in the refrigerator. Small cuts and ground meat takes about a day; larger pieces like roasts can take 2 to 3 days. Once the meat defrosts, it will be safe in the refrigerator for 3 to 5 days before cooking. Cold Water: To defrost meat in cold water, do not remove packaging. Be sure the package is airtight or put it into a leakproof bag. Submerge in cold water, changing the water every 30 minutes so that it continues to thaw. Small packages may defrost in an hour or less; a 3- to 4-pound roast may take 2 to 3 hours. Microwave: When microwave defrosting, plan to cook the meat immediately after thawing because some areas of the food may become warm and begin to cook during microwaving. Holding partially-cooked food is not recommended because any bacteria present wouldn’t have been destroyed.
(source: USDA.gov)