A Black and Tan beer is made up of two beers: a Bass pale ale at the bottom, and a Guinness stout on top. The stout is less dense than the pale ale, allowing it to float on top and create the classic two-tone pint for which the drink is named. The combination of the two beers creates a unique flavor that is both sweet and bitter. The pale ale adds a light, malty sweetness, while the stout adds a roasted, coffee-like bitterness.