A dirty martini is a popular cocktail that combines gin or vodka with dry vermouth and olive brine. The addition of olive brine gives the drink its "dirty" flavor, which adds a savory, salty twist. Typically, it is garnished with one or more olives. To prepare a dirty martini, the ingredients are mixed with ice and then strained into a chilled glass. The drink can be adjusted to taste by varying the amount of olive brine used. It is often served in a martini glass and is a favorite among cocktail enthusiasts for its bold flavor.