Thawing food safely
The USDA only officially recommends three methods to safely thaw food: in your refrigerator, in cold water and in the microwave. There are other effective ways to defrost or cook frozen food that are generally considered to be safe but the USDA only explicitly endorses these three methods. But before we get into detailed explanations of those methods, we should know why they are necessary.
The Danger Zone
The foodborne bacteria, yeasts, mold and viruses contaminating your food only become inactive when frozen, they aren’t destroyed by the freezing process like many people assume. Freezing only stops the clock — the second you take your food out of the freezer to thaw, that clock immediately starts ticking again. At temperatures between 40 to 140 degrees F, a range the USDA has deemed the Danger Zone, harmful foodborne microorganisms come back to life and start to rapidly multiply, doubling every half an hour or so until after about two hours, the thawing food has become too unsafe to eat and should be discarded. If the ambient temperature is 90 degrees F or above, the food should be discarded after only 1 hour.
This is why you should never set your food out to thaw at room temperature. The USDA goes further saying, “Also, never thaw foods in a garage, basement, car, dishwasher or plastic garbage bag; out on the kitchen counter, outdoors or on the porch. These methods can leave your food unsafe to eat.” A car? A garbage bag? The bizarrely inclusive nature of this warning clearly demonstrates the importance of being educated and informed on these potentially life-threatening food safety issues. Your dishwasher doesn’t have a defrost button for a reason.
Refrigerator thawing is the preferred way to defrost food because it holds numerous advantages over the other two approved methods.
It’s the easiest. Simply place your frozen meat in the refrigerator in a leak-proof bag or pan to catch drips and forget about it until its ready to be cooked. There’s no need to continually change water or check temperatures.
It’s the safest. Your thawing food is under constant refrigeration and will never have a chance to reach Danger Zone temperatures. In fact, unlike the other two defrosting methods, you don’t have to cook the food immediately after thawing. Chicken and ground beef can hold for 1-2 days and steaks, roasts and chops can hold for 3-4 days. Thawing food in your refrigerator will even allow you to refreeze your food without cooking it first if necessary (albeit with some quality loss).
The only downside to this method is that it a requires lengthy thaw times — as much as 24 hours per every 5 pounds of weight. Even small amounts of food might need a full day to completely thaw, so if you forget to take it out of the freezer on time, you’re out of luck. But hey, patience and smart planning should be a part of every cook’s skillset.
Refrigerator Thawing Times
|Beef||Required Thawing Time|
|Rolled rib roast||8-10 hours per pound|
|Standing rib roast||7-8 hours per pound|
|Rump roast||7-8 hours per pound|
|Sirloin steak (1-inch thick)||8-10 hours per pound|
|Round steak||5-6 hours|
|Ground beef (1 pound package)||18-20 hours|
|Patties (separated)||5-6 hours|
|Stew meat (1 pound package)||18-20 hours|
|Pork||Required Thawing Time|
|Cutlets||7-8 hours per pound|
|Steak||7-8 hours per pound|
|Sausage (1 pound package)||18-20 hours|
|Veal/Lamb||Required Thawing Time|
|Chops (1/2-inch to 3/4-inch thick)||7-8 hours|
|Chicken||Required Thawing Time|
|Whole chicken (1 pound)||4-6 hours per pound|
|Whole chicken (5 pounds)||24 hours|
|Whole chicken (10 pounds)||48 hours|
|Separated chicken (1/2 pound)||12 hours|
|Separated chicken (1 pound)||24 hours|
|Separated chicken (2 pounds)||48 hours|
|Turkey||Required Thawing Time|
|Whole turkey (4-12 pounds)||1-3 days|
|Whole turkey (12-16 pounds)||3-4 days|
|Whole turkey (16-20 pounds)||4-5 days|
|Whole turkey (20-24 pounds)||5-6 days|
|Whole turkey (1 pound)||48 hours|
Cold Water Thawing
This method is much faster than refrigerator thawing but will require you to change the water every 30 minutes. Place the frozen food in a leak-proof package or plastic bag with as much air remove as possible. Handle the food carefully, as any leak could cause the tissue in your food to absorb extra water or worse, introduce bacteria from the surrounding environment. Submerge the frozen food in cold tap water (under 40 degrees F) and weight the food down if necessary. Change the water completely every half an hour, adding ice or cold water as needed to maintain the correct temperature.
Small packages of meat — like a pound of beef or chicken — might thaw in an hour or less. Three or four pound packages might take 2 to 3 hours. In general though, allow about half an hour per pound of frozen food. Once the food has thawed completely, it must be cooked immediately. You can refreeze the food only once it has been cooked.
For those seeking the very best their frozen meat has to offer (and who isn’t), a very cold water bath is the most effective method to minimize “purge” or fluid loss. Follow the same steps as above but place the meat and the cold water in an insulated cooler. After an hour, add a quart of ice . Add more ice as needed, about every hour, to maintain a temperature of 40 degrees F or below. Stir the water occasionally, to disrupt the cold water envelope that surrounds the meat.
While microwave thawing is considered safe, it isn’t ideal. In fact, it’s unfit by design. The frequency microwaves operate at (2,450 MHz) was chosen because of how well it stimulates water. But frozen water is crystalline and almost invisible to microwaves at that frequency. So even with the proper defrost settings, food thaws inconsistently as it only heats the liquid water, with some areas becoming warm and even cooked, which can bring the food into the Danger Zone range. Cook any food you thaw in the microwave immediately to help prevent bacterial growth.
If you do use your microwave to defrost, remove the original packaging, plastic wraps, cartons or polystyrene trays from the meat, and place on a clean container or platter to catch any juices that leak out and prevent contaminating your microwave.
Follow your instruction manual for the proper thawing instructions for your model microwave. If, in the likely event you can’t find your manual, your auto defrost button should work fine. Many newer models just require you to know the code and approximate weight of the food you’re thawing to get acceptable results.
If you don’t have a reliable defrost button, reduce the power to 30 or 50-percent and check your food frequently as it thaws, flipping and/or rearranging as necessary. Many meats require about 8-10 minutes per pound to properly defrost so that might be good way to estimate how much time you’ll need to defrost. Do not use full power or your food will be cooked on the outside and frozen on the inside, a worst case scenario for safety and taste.
In a related note, many people assume their frozen meals have already been cooked before freezing and packaging but this is a dangerous misconception. You should take as much care preparing your boxed frozen meals as you do food you have frozen yourself. After thawing in the microwave, always cook immediately. You can refreeze the food only once it has been cooked.
Other Thawing Methods
Cooking without thawing
The USDA says it’s safe to cook food from a frozen state, with the caveat that you add at least 50% more cooking time, perhaps nearly twice as much depending on what your cooking. In fact, not only is cooking from frozen safe, there are even some strong arguments among food scientists and steak lovers for never thawing frozen steaks at all. Frozen steaks brown just as well as thawed steaks, yet retain nearly 10% more moisture and routinely beat their thawed counterparts in taste tests. Fish, shrimp and chicken can all be cooked from frozen with great success.
Warm water bath
This method is approved by the National Restaurant Association and standard culinary textbook. Simply unwrap frozen meat and place it in a bowl of tepid water (105 degrees F) under rapidly dripping water that is slightly cool. The moving water helps regulate the temperature and keep bacteria growth to a minimum.
Hot water bath
Very similar to the sous vide technique (which itself can produce stunning results from frozen food), this method is meant to quickly defrost smaller, thinner pieces of meat. Frozen meat is sealed in zipper-lock bags and submerged in 140 degree F water until it is completely thawed. The whole process takes about 8-12 minutes, keeps bacterial growth to a minimum and doesn’t cook the meat (though it does turn chicken opaque).
Instant Pot/Pressure cookers
Pressure cookers like the Instant Pot are tightly sealed and operate at very high temperatures. They are a safe and easy way to cook frozen food as long as the food isn’t too large (so avoid frozen roasts) and the cooking method is appropriate (avoid braising and steaming). To cook frozen meat, brown what you can with a little oil in a cast iron skillet or using the sauté/browning function of your Instant Pot. Add cooking liquid (usually about a cup) and allow for extra cooking time.
|Frozen Beef/Pork||5 minutes per inch of thickness|
|Frozen chicken||4 minutes per per inch of thickness|
|Frozen whole chicken or turkey||1 minute per pound|
Also please be aware that large frozen pieces of meat can take up to 40 minutes to achieve pressure sometimes causing your electric pressure cooker to time out and restart.
Metal pans/defrosting trays
The USDA repeatedly and explicitly warns about thawing food at room temperature, but many professionals routinely use a cast-iron skillet or steel pan to rapidly thaw their meat anyways. It <em>can</em> be done safely as long as the meat is relatively thin, lays flat against the tray’s surface and the thawing process can be completed in at most two hours before bacteria growth can really start to develop (1 hour if the ambient temperature is 90 degrees F or above). The value of defrosting trays are the subject of some debate but at the end of the day they transfer heat exactly like almost any pan in your kitchen would. In fact, the only notable difference between a dedicated defrosting tray and a pan you have lying around your kitchen is that a tray will most likely have grooves to drain off excess liquid.
Instant Pot/Slow cookers
This one is a bit murky and more than a little contentious. The USDA states that you should “always thaw meat or poultry before putting it into a slow cooker”. Manufacturers claim, along with many experts, that cooking frozen meat in a slow cooker is perfectly safe as long as you plan on a little extra cooking time and make sure your food is served at a safe temperature (160 degrees F for ground beef, pork, lamb and veal / 165 degrees F for poultry). This is considered to be the temperature(s) where the bacteria present in our food has been killed off to a safe level.
However, the USDA is concerned that frozen food spends too much time in slow cookers thawing out at Danger Zone temperatures giving bacteria ample time to produce the heat-resistant toxins that actually cause foodborne illnesses. It makes little difference if the bacteria themselves are destroyed by an internal temperature of 165 degrees F if the toxins survive. That said, everyone has to decide if convenience outweighs safety. Just promise me you won’t be the guy thawing out his pork shoulder in a garbage bag in the bed of his truck parked in his garage.
Sources: FSIS (USDA),1, 2, Food Safety, Cooks Illustrated,1, Eat Right, Epicurious,1, The Kitchn,1, 2, AmazingRibs, CrowdCow,1, NYTimes, RealSimple, HuffPost, MomStart, BeefLovingTexans, Leaf.tv, HIPCooking
Image: RawPixel/Markus Spiske