Beef – quickly and safely thaw frozen ground beef, what are the options

I suppose that depends on what you're defrosting it for.

The microwave (on low power) is safe and quick. The downside is that you're using a microwave, which means there's a good chance you'll actually cook the outside slightly in the process, and you're killing enzymes that are normally part of the flavour. The lower the heat, the less the impact of this, but it's still a problem. If I'm preparing the meat for marinating, stir-fry, etc., something with a powerful or thick sauce, then I wouldn't worry about it, but if it's going onto a grill with just a little bit of seasoning, you might want to avoid this.

Running it under warm water would seem to work, but I've found that it takes forever to defrost this way (the exterior will loosen up but the interior stays stubbornly frozen), and you're soaking it in the process. This really isn't suitable if you need to pound or fold the meat or do anything complicated with it.

I would use the microwave if desperate, but it's really best to thaw the meat in the refrigerator or, if you're in a bit of a hurry, the sink. It takes longer, but it'll turn out much better than the microwave in terms of flavour and tenderness.

P.S. One other word of advice: If you're making a dish that requires the chicken to be cut or sliced, it's best not to defrost it all the way. It's easier to cut when frozen, and will defrost very quickly once it's in pieces. I'm mainly talking about the breast here, this doesn't work so well with meat stuck to bones.

Update: I'm noticing a lot of recent hubbub about the dangers of defrosting in the sink / on the countertop or using warm water and I wanted to clarify something. Please note that that the advice above applies to chicken that will be immediately cooked after defrosting and that the defrosting is done over a period shorter than 2 hours.

Raw chicken must not be kept at any temperature above 40° F (4.4° C) for more than an hour or so. Do not defrost a chicken breast in the sink and then toss it back in the fridge. Definitely don't try to defrost a whole bird this way - stick to the refrigerator or very cold running water.

As long as you follow the above precautions and cook the chicken thoroughly (up to an internal temperature of 165° F), you're not in any serious danger of salmonella poisoning, even if the original piece of meat was contaminated - and most chicken sold today is contaminated, for the record.

If the meat is going back in the refrigerator for marinating or you plan to delay cooking for any other reason, then you need to either thaw it very fast (using the microwave) or at a very low temperature (using the refrigerator or cold running water).

A lot of bacteria grows in the range of 40-100°F (4-38°C) (i.e. room temperature). It's definitely not recommended to defrost meat at room temperature. In fact, you are not supposed to leave meat at room temperature for more than an hour.

However, defrosting in the refrigerator can take a long time and require you to plan at least one day ahead of time. I'm not so good at this, which leads to a safe and fast solution: Defrost meat in a waterproof ziploc bag in cold water. Change the water every 30 minutes until defrosted. The water is a better conductor of heat than air, so the defrosting is quite fast and the water is cold so there's minimal safety risk.

From the USDA:

Uh, oh! You're home and forgot to defrost something for dinner. You grab a package of meat or chicken and use hot water to thaw it fast. But is this safe? What if you remembered to take food out of the freezer, but forgot and left the package on the counter all day while you were at work?

Neither of these situations are safe, and these methods of thawing lead to foodborne illness. Food must be kept at a safe temperature during "the big thaw." Foods are safe indefinitely while frozen. However, as soon as food begins to defrost and become warmer than 40 °F (4 °C), any bacteria that may have been present before freezing can begin to multiply.

Foods should never be thawed or even stored on the counter, or defrosted in hot water. Food left above 40 °F (unrefrigerated) is not at a safe temperature.

Even though the center of the package may still be frozen as it thaws on the counter, the outer layer of the food is in the "Danger Zone," between 40 and 140 °F (4 °C and 60 °C) – at temperatures where bacteria multiply rapidly.

When defrosting frozen foods, it's best to plan ahead and thaw food in the refrigerator where food will remain at a safe, constant temperature – 40 °F (4 °C) or below.

There are three safe ways to defrost food: in the refrigerator, in cold water, and in the microwave.

Refrigerator Thawing Planning ahead is the key to this method because of the lengthy time involved. A large frozen item like a turkey requires at least a day (24 hours) for every 5 pounds of weight. Even small amounts of frozen food -- such as a pound of ground meat or boneless chicken breasts -- require a full day to thaw. When thawing foods in the refrigerator, there are several variables to take into account. Some areas of an appliance may keep the food colder than other areas. Food placed in the coldest part will require longer defrosting time. Food takes longer to thaw in a refrigerator set at 35 °F (2 °C) than one set at 40 °F (4 °C).

After thawing in the refrigerator, ground meat and poultry should remain useable for an additional day or two before cooking; red meat, 3 to 5 days. Foods defrosted in the refrigerator can be refrozen without cooking, although there may be some loss of quality.

Cold Water Thawing

This method is faster than refrigerator thawing but requires more attention. The food must be in a leak-proof package or plastic bag. If the bag leaks, bacteria from the air or surrounding environment could be introduced into the food. Also, meat tissue can also absorb water like a sponge, resulting in a watery product.

The bag should be submerged in cold tap water, changing the water every 30 minutes so it continues to thaw. Small packages of meat or poultry – about a pound – may defrost in an hour or less. A 3- to 4-pound package may take 2 to 3 hours. For whole turkeys, estimate about 30 minutes per pound. If thawed completely, the food must be cooked immediately.

Foods thawed by the cold water method should be cooked before refreezing.