You can safely defrost chicken breasts by submerging them in cold water, heating them in the microwave, or leaving them in the refrigerator. Handle chicken or any other perishable food item with care in order to prevent the growth of potentially harmful bacteria in your food. It is not safe to defrost chicken by leaving it on a counter or by putting it in warm water because both environments allow the meat to get too warm. Raw chicken should not be allowed to get warmer than 40 degrees Fahrenheit (4 degrees Celsius) because anything above that temperature allows any bacteria present in the food to reproduce and can quickly make the chicken unsafe to eat.
If you defrost chicken breasts by putting them in cold water, thawing will take about one hour per pound (0.45 kg) of meat. Very large pieces take longer. Cutting the breasts into smaller pieces allows the chicken to defrost more quickly.
Make sure that the chicken is tightly wrapped so that bacteria from the raw meat doesn't contaminate the surfaces around it. Keeping it wrapped also prevents water from soaking into the meat which isn't dangerous but can negatively affect the quality of your chicken. If you have a hard time keeping your package of chicken breasts submerged, try putting a glass baking pan on top of it to weigh it down. Make sure that everything that comes into contact with the package is thoroughly washed afterwards.
It is difficult to say how long it takes to defrost chicken breasts in the microwave because each appliance varies in power and efficiency. It is usually best to heat the chicken on a medium power setting for a couple of minutes at a time and to check to see if any parts have started to cook. It is also safe to cook frozen chicken without defrosting it beforehand, so theoretically, you can combine the defrosting and cooking processes if you plan to also cook the chicken in the microwave. As always, carefully clean any surface that the chicken comes in contact with while it is raw.
The most highly recommended and safest way to defrost chicken breasts is to let them sit in the refrigerator until they are completely thawed. This process can take about five hours per pound (0.45 kg), but to be on the safe side, it is usually best to defrost chicken breasts for a whole day or at least overnight. When defrosting this way, make sure your refrigerator is set to 40 degrees Fahrenheit (4 degrees Celsius) or lower. The chicken breasts should be kept wrapped, and it is also a good idea to put a plate or pan under them so that any liquid that drips off as they thaw is contained and can be washed off afterwards.