The grades of meat are based on the texture, firmness and color of meat, age or maturity of the animal and the marbling of fat within the meat cut. The term aging simply means the length of time cuts are stored under controlled conditions of temperature and humidity before they are ready for sale at the meat counter. Beef, for example, that is aged between 21-30 days is better tasting because the connective tissue breaks down, which in turn, makes the meat more tender. Dry aging, whereby a carcass of beef is hung for an allotted period of time, is by far a more preferred method of aging but can be more costly to the shop owner because of the shrinkage of the carcass by the time it is deemed ready to process for the counter.
Beef cuts are named for their anatomical location on the carcass. Cuts from the centre of the carcass - the loin and rib - are suspension muscles. They receive little exercise and therefore are the most tender. These cuts are best cooked by dry heat methods. Cuts from the front and rear of the carcass - the chuck and round - are responsible for locomotion. These heavily exercised muscles are less tender and will require marinating or a slower, moist cooking method.