Freezing or refrigerating meat and poultry prevents the growth of dangerous bacteria, such as salmonella and listeria monocytogenes. Some defrosting techniques may facilitate bacterial growth. Ingesting these bacteria may lead to food poisoning, so it's safer to immediately cook defrosted meat instead of freezing and thawing it again.
Defrosting in the Refrigerator
If you defrost meat or poultry in the refrigerator, you can safely refreeze it again before cooking because the constant temperature of a refrigerator is cold enough to prevent rapid bacterial growth. However, defrosting meat or poultry in the refrigerator may take a day or more, depending on the size of the cut. If you don't plan ahead, you may need to use another defrosting technique.
Cold Water and Microwave Defrosting
If you don't have time to defrost meat or poultry in the refrigerator, you can defrost it by submerging it in cold water, changing the water every 30 minutes, or by putting it in the microwave on the defrost setting. If you use these defrosting strategies, you should cook the meat immediately. Defrosting meat in cold water or in the microwave may allow bacterial growth, and if too many bacteria grow, cooking the meat will not kill them all. However, you can refreeze meat after cooking.
Unsafe Defrosting Techniques
Never defrost meat or poultry at room temperature or in hot water because bacteria will begin to multiply rapidly at these temperatures. Discard raw meat or poultry that has been kept at room temperature for more than two hours, or more than one hour at 32.2 degrees C or more.
Cooking Frozen Meat
You don't have to defrost meat or poultry before cooking. However, cooking frozen meat or poultry will take longer than cooking defrosted cuts. Use a food thermometer to make sure you cook lamb, veal and beef steaks to 62.8 degrees Celsius, pork and minced meat, veal or lamb to 160 degrees and poultry to 165 degrees. Don't rely on the appearance of meat to know when it's done; undercooked meat may look safe but still contain bacteria.