All Scotch whisky was originally made from malted barley. Commercial distilleries began introducing whisky made from wheat and rye in the late 18th century, Scotch whisky is divided into five distinct categories: single malt Scotch whisky, single grain Scotch whisky, blended malt Scotch whisky.All Scotch whisky must be aged in oak barrels for at least three years

-Reisterstown Wine & Spirits