Q: What’s the best way to defrost a large roast? Thawing it in the refrigerator takes an extremely long time.
A: First, a note about frozen meat: It doesn’t spoil, since any bacteria that might be present are dormant at freezing temperature. (Freezing doesn’t kill the bacteria, however.) But as meat thaws, it’s essential that it not enter the “danger zone,” which is between 40°F and 140°F (4.4°C and 60°C)—the temperature range at which bacteria multiply most rapidly, thereby increasing the risk of foodborne illness.
With that said, there are several ways to safely defrost meat and poultry, according to the USDA. That includes refrigerator thawing, which, as you point out, is a lengthy undertaking that you must plan for, since a large item (like a frozen turkey) needs about 24 hours for every 5 pounds (yes, that means a 12-pound frozen roast or turkey will take more than two days!). Bear in mind that even small pieces of meat can take all day to thaw. How long exactly depends on such factors as the size and thickness of the meat, where in the fridge the meat is placed (some spots are colder than others), and the temperature setting of the refrigerator (it will take longer at 35°F than 40°F).
This is the safest method, however, because the meat remains at a constant safe temperature of 40°F or below during the entire thawing process. Just be sure that your fridge is properly set (check it with an appliance thermometer, placed near the door, not tucked away in the back). Once the meat thaws, you can cook it right away or keep it refrigerated for 1 to 2 more days (for poultry, ground meat, fish) or 3 to 5 days (for red meat cuts). Food experts say that refrigerator thawing is also best for preserving the quality of the meat.
A faster option is cold water thawing, which should take about 30 to 60 minutes per pound of frozen meat. But care must be taken to keep the meat safe. Seal it in a leak-proof bag (or keep it in its store wrapping if that’s secure), then immerse it in cold water; change the water every 30 minutes. Once thawed completely, the meat should be cooked right away.
The last—and quickest—method is microwave thawing, which is especially handy if you forgot to take the meat out of the freezer in advance and are in a hurry. Remove the plastic wrapping the meat came in and place the meat on a microwave-safe dish. You can use the “defrost” or low-power feature (usually 30 percent power), or check the owner’s manual to determine the correct power level and time. Expect it to take about 7 to 8 minutes per pound of meat. Because microwaving can thaw the meat unevenly (creating potential “hot spots”), bacteria can start to multiply, which means that you must cook it immediately afterward.
How not to thaw meat: Don’t run it under hot water or leave it on the counter, as this allows the outer layers to warm to unsafe temperature, while the interior remains frozen.
Keep in mind that if you need to start cooking the meat before you can thaw it, it’s safe to do so, though it will take about 50 percent longer than usual. To get answers to other meat and poultry food-safety questions, the USDA provides a hotline number at 202-720-2791 (where you can speak with a food-safety specialist), or you can visit ask.usda.gov or send an email to firstname.lastname@example.org.