Bourbon whiskey is the most common American version of this spirit. However, what's the difference between whiskey and bourbon? The answer is simple: Bourbon needs to come from America and contain at least 51% corn. Whiskey, instead, can come from many different countries. Think, for example, about Scotch whisky and the versions of this spirit from Ireland and England. Also, bourbon producers can only use their charred-oak barrels once. After the barrel has infused its flavor notes into the bourbon, the producers pass it down to other distilleries that use them to age other liquors and even wine, to create complex and interesting flavor profiles.