Beef, flesh of mature cattle, as distinguished from veal, the flesh of calves. The best beef is obtained from early maturing, special beef breeds. High-quality beef has firm, velvety, fine-grained lean, bright red in colour and well-marbled. The fat is smooth, creamy white, and well distributed. In young beef the bones are soft, porous, and red; the less desirable mature beef has hard white bones. Beef tenderness and flavour are improved by aging; in one common aging method the carcass is hung for about two weeks at approximately 36 °F (2 °C), encouraging physical changes in the muscle tissue that enhance the quality of the meat.