A Moscow Mule cocktail includes vodka, ginger beer and lime juice and is often garnished with a wedge of lime. The amount of each ingredient added varies depending on the recipe or bartender.
The Moscow Mule is a vodka-based cocktail that was invented in 1941 by John G. Martin and Jack Morgan. It is traditionally served on the rocks and in a copper mug, although Collins glasses are also commonly used. Smirnoff Vodka, which was barely recognized at the time, became the vodka of choice for the Moscow Mule when Martin purchased the company in 1939 and brought its spirits over to the Cock 'n Bull restaurant, where the drink won its famed reputation.
Recipes vary slightly in ingredient order and measurements, but most start with ice followed by the addition of lime juice and vodka before finishing it off with ginger beer. The preparer then stirs the drink with a rod and serves it. BonAppetit.com features the Moscow Mule recipe from Cock 'n Bull Bar in Santa Monica, California, which uses 1/4 cup vodka, 1 tablespoon lime juice and 1/2 cup chilled ginger beer. Chow.com's recipe uses slightly less vodka with 1 1/2 ounces and doesn't specify the amount of ginger beer. Preparation times range from three to five minutes.