used for making beef stock. Meat from younger cows (calves) is called veal. Beef from steers and heifers is similar. Beef is first divided into primal cuts, large pieces of the animal initially separated by butchering. These are basic sections from which steaks and other subdivisions are cut. The term "primal cut" is quite different from "prime cut", used to characterize cuts considered to be of higher quality. Since the animal's legs and neck muscles do the most work, they are the toughest; the meat becomes more tender as distance from hoof and horn increases. Different countries and cuisines have different cuts and names, and sometimes use the same name for a different cut; for example, the cut described as "brisket" in the United States is from a significantly different part of the carcass than British brisket. Aging and tenderization To improve tenderness of beef, it is often aged (i.e., stored refrigerated) to allow endogenous proteolytic enzymes to weaken structural and myofibrillar proteins. Wet aging is accomplished using vacuum packaging to reduce spoilage and yield loss. Dry aging involves hanging primals (usually ribs or loins) in humidity-controlled coolers. Outer surfaces dry out and can support growth of molds (and spoilage bacteria, if too humid), resulting in trim and evaporative losses. Evaporation concentrates the remaining proteins and increases flavor intensity; the molds can contribute a nut-like flavor. After two to three days there are significant effects. The majority of the tenderizing effect occurs in the first 10 days. Boxed beef, stored and distributed in vacuum packaging, is, in effect, wet aged during distribution. Premium steakhouses dry age for 21 to 28 days or wet age up to 45 days for maximum effect on flavor and tenderness. Meat from less tender cuts or older cattle can be mechanically tenderized by forcing small, sharp blades through the cuts to disrupt the proteins. Also, solutions of exogenous proteolytic enzymes (papain, bromelin or ficin) can be injected to augment the endogenous enzymes. Similarly, solutions of salt and sodium phosphates can be injected to soften and swell the myofibrillar proteins. This improves juiciness and tenderness. Salt can improve the flavor, but phosphate can contribute a soapy flavor. Cooking methods These methods are applicable to all types of meat and some other foodstuffs. Dry heat Internal temperature Beef can be cooked to various degrees, from very rare to well done. The degree of cooking corresponds to the