Scotch, quite simply, is whisky made and aged at least three years in Scotland. All whisky made in Scotland is Scotch, and must follow specific production regulations. All Scotch varieties fall within two broad categories or are blends of these two: malt whisky and grain whisky. Malt whisky must be 100 percent malted barley. Grain whisky may include wheat, rye, corn or other grains. Scotsman Andrew Usher pioneered mixing grain and malt whiskies together, creating blended whisky in 1853. Blending revolutionized the distilling industry, creating smoother and milder whiskies than Scotland’s traditional malt whiskies. Other master blenders, such as Johnnie Walker, John Dewar and James and John Chivas followed suit, founding some of the world’s most famous brands. While there are examples of 100 percent grain whisky, most Scotch grain whisky is blended with malts to make blended whisky.