Scotch is made mostly from malted barley, while bourbon is distilled from corn. Scotch is whiskey made in Scotland, while bourbon is whiskey made in the U.S., usually Kentucky. Whiskey is defined as a type of distilled alcoholic beverage made from various fermented grain mashes, including barley, rye, wheat and corn. It is usually aged in wooden casks. When it comes to the difference between scotch, whiskey and bourbon, it’s both geographic and about ingredients.