Whisky is a spirit made from fermented grain (usually barley, corn, rye and/or wheat). The grains are used to create a mash, which involves the malted grain, water and heat to convert the starch in the grains to sugar. The sugars are then fermented and then distilled. The distillation process commonly takes place in a copper still producing a high alcohol product that is then diluted back to a specific alcoholic concentration. The spirit is usually aged in wooden barrels depending on the type of whisky.