The Mule is a simple, spicy highball — a base spirit over ice with fresh lime and a generous top of ginger beer, traditionally served in a frosty copper mug. The vodka Moscow Mule started it, but the formula swaps cleanly: tequila for a Mexican Mule, bourbon for a Bourbon Mule, and so on. Ginger's heat and lime's acidity keep every version crisp.
