Frozen meats can be safely frozen indefinitely as long as your freezer maintains a temperature of 0°F or lower. At this temperature, bacteria, yeasts, and molds are inactive (not destroyed). Freezing meat simply stops the clock when microbes are concerned. So, if a piece of meat is about to go bad when you freeze it, it's about to go bad when after you thaw it. It's best to freeze fresh meat shortly after purchase unless you plan on using it.
Enzymes are not stopped by freezing, but merely slowed down, so the quality of the food may diminish over time. This is not a safety issue, but a food quality conern.
An avoidable quality detractor is freezer burn. Freezer burn occurs when air comes in contact with the surface of the food. Frozen water on the surface or just under the surface sublimates (like evaporation except going from solid directly to vapor) into the air. (This is the same reason why ice cubes slowly "disappear" in the freezer.) This causes moisture to be lost from the meat over time resulting in discoloration and a dry, leathery texture. The meat is still safe to eat, but the freezer burned sections won't taste good. Simply cut the affected portions off before or after cooking.
The risk of freezer burn can be minimized by good packaging. Although you can safely freeze meat in the packaging provided by the market, the plastic used are usually air permeable. Repacking the meat so that as little air as possible comes into direct contact with the food will reduce the chances of freezer burn. Some effective solutions are to pack the meat in liquid (like chicken parts in broth), vacuum sealing, wrapping in heavy-duty aluminum foil, or using a plastic freezer bag.
Packaging Meat For Freezing
Here's how I freeze inidividual pieces of meat:
First I place the a portion of meat onto a large piece of heavy-duty aluminum foil.
Fold two sides over so they meet in the center. Take the overlapping foil and fold in half to form a seal that runs along the package. Fold again in half in the same direction to form a double seal.
Flatten the open ends to form two flaps. If the flaps are long enough to overlap, fold them over the meat and fold the overlap in half to form a seal. Fold again to form a double seal (as shown below). If the flaps are not long enough to overlap, simply fold each flap in half and once again to seal the ends. The foil should fit tightly against the meat.
After all the meat has been wrapped, label a plastic freezer bag and place foil wrapped meat inside. Squeeze as much air as possible out of the bag and seal. Plastic bags that are not rated for freezing may be gas permeable and may result in freezer burn if frozen for longer than two months.
Wrapping the meat in aluminum foil first keeps portions separate, seals each piece of meat, and allows me to selectively thaw or refreeze portions. When freezing meat in liquid (for example, chicken pieces in broth), I just place the meat and liquid in a freezer bag and make sure that the meat is either in direct contact to the bag or covered by the liquid during freezing.
There are a few safe methods of thawing meat, but only one way that allows you to refreeze the meat if you don't use it. Thawed meat inside the refrigerator is safe to be refrozen as long as the refrigerator maintains a temperature of 40°F or less.
1. Refrigerator - Takes a long time to thaw (one or two days for modest sized meats, 5 hours per pound for large meats like whole chicken or turkey). Results in an even thaw (same temperature throughout once it is done). Can be frozen after thawing.
2. Cold Water Bath - Place the meat in a leak proof bag and submerge in cold water until defrosted. Change the water every 30 minutes to an hour for the duration of the thaw. Cook the meat immediately. Do not refreeze.
3. Microwave Oven - Follow the directions provided with your microwave oven when defrosting. Meat usually comes out unevenly defrosted, so some parts may be warm (a prime breeding ground for microbes). Cook immediately. Do not refreeze.