You’ll need to change the water every 30 minutes to ensure that it stays sufficiently cold. Using this thawing method, small packages of frozen meat or poultry (about a pound) can defrost in one hour or less. For larger items, you should estimate about 30 minutes of defrosting time per pound of food.Once the food is thawed completely, you’ll need to cook it immediately.oultry, fish and ground meat that’s been defrosted in the fridge can be kept for an additional 1 to 2 days in the refrigerator before cooking. Beef, pork, lamb or veal (roasts, steaks or chops) will keep refrigerated for another 3 to 5 days after thawing.