Scotch Whisky is more than just a drink; it is a legally protected product that must be produced in Scotland and aged in oak casks for at least three years. The unique flavors of Scotch are often defined by five distinct regions: Highlands, Lowlands, Islay, Speyside, and Campbeltown. For example, whiskies from Islay are famous for their 'peaty' or smoky flavor. This occurs when peat—an accumulation of partially decayed vegetation—is burned to dry the malted barley. The smoke from the peat infuses the grain with phenols, which survive the distillation process. Speyside, however, is known for sweeter, fruitier whiskies. The water source, the shape of the copper stills, and the type of barrel (such as former Sherry or Bourbon casks) all contribute to the complex final profile.