<human>:  What is the difference between bourbon and Scotch whiskey?
<bot>: The main difference between bourbon and Scotch whiskey is that bourbon is a type of American whiskey made primarily with corn, while Scotch whiskey is a type of whiskey made primarily from malted barley and aged in oak casks for at least three years. Additionally, bourbon is aged in new charred oak barrels, whereas Scotch is generally aged in used oak barrels. Lastly, while bourbon is usually distilled to no more than 80 percent alcohol by volume (ABV), Scotch whisky is distilled to a slightly lower strength of around 70-80 percent ABV.