A distilled spirit made from a fermented mash of sugars derived from cereal. Scotch malt whisky and Irish whiskey are made from malted barley from which the starch is converted to sugars through germination. Bourbon whiskey is made from a grain mixture containing at least 51 per cent corn. Rye whiskey is made from at least 51 per cent rye grain. The malting process releases enzymes used to convert the starch to sugars. It is then roasted and mashed as a fermentation that converts the sugars into alcohol. The fermented wort liquid is distilled and the distillate collected. Maturation takes place in wooden casks. For Scotch whisky, this must be for a minimum of three years. Single malt whisky is from a single distillery. Most whiskies are blended.