Rotate stock—first in, first out. Frozen meats do not keep indefinitely. Recommended shelf life at 0°F (-18°C) for beef, veal, and lamb: 6 months; for pork: 4 months (pork fat turns rancid easily in the freezer).
Defrost carefully. Tempering in the refrigerator is best. Defrosting at room temperature encourages bacterial growth.
Do not refreeze thawed meats. Refreezing increases loss of quality.