From The Food Encyclopedia by Jacques Rolland and Carol Sherman
The fat-coated, curved organ that removes waste from the bloodstream and, along with water, excretes it as urine. Kidneys occur in pairs and may have one or more lobes each; they darken with age and acquire a tougher texture and a stronger smell and taste. Classed as variety meat, kidneys from cattle, pigs, poultry, rabbit and sheep are eaten; calves' liver is considered a delicacy. They should be eaten almost immediately after they are purchased. Usually soaked in water first to minimize any odor, then trimmed of fat if necessary, kidneys are cooked slowly by braising, broiling or simmering in pies or stews. They may also be sliced and stir-fried in China, grilled for a full breakfast in England, served on skewers in the Middle East or added to soup in Poland.
