Olive oil is made from the fruit of the olive tree, and is an integral part of Mediterranean cuisine. The extraction process begins with milling whole olives in a stone or metal grinding bowl. The olives are then pressed with a heavy weight and the liquid that comes out is a mixture of water, crushed olives, and oil. The olives are then crushed and passed through a series of screens to remove the skin and flesh, leaving behind just the oil. The oil is then either bottled, or sold to be processed further.