Ginger beer is a non-alcoholic or lightly alcoholic beverage known for its robust and spicy ginger flavor, which makes it a popular mixer in a variety of cocktails. Traditionally, ginger beer was brewed through a fermentation process that resulted in a mildly alcoholic drink, but most modern versions are non-alcoholic and carbonated, similar to ginger ale but with a stronger, more pronounced ginger taste.

In the context of cocktails, ginger beer is a key ingredient in several classic drinks. The Moscow Mule, for example, combines vodka with ginger beer and lime juice, served in a copper mug to enhance its refreshing qualities. Another popular cocktail, the Dark 'n' Stormy, pairs dark rum with ginger beer and a splash of lime. These cocktails rely on the spicy, effervescent qualities of ginger beer to complement and enhance the flavors of the spirits they are mixed with, making it an essential component in many bartenders' repertoires.