Finishing refers to the practice of maturing a spirit, for short periods of time, in a cask that previously held other liquids. The process allows whiskey makers to add additional layers of flavor to a whiskey. The practice started with the Scotch whisky industry. The technique has become quite common in Scotland and is being adopted by other whiskey producers around the world. It has even been used by other spirit producers, ranging from rum to brandy to tequila.