A cosmopolitan is a cocktail made with vodka, Cointreau or Triple Sec, cranberry juice, and fresh-squeezed lime juice or sweetened lime juice. Informally, it is referred to as a Cosmo.
According to the International Bartenders Association the original recipe is based on vodka citron, lemon-flavored vodka. The cosmopolitan is a relative of cranberry coolers like the Cape Codder. Though often presented far differently, the cosmopolitan also bears a likeness in composition to the kamikaze cocktail.
This origins of the cosmopolitan are somewhat disputed. It is likely that the drink was created independently by different bartenders since the 1970s. It is generally recognized that John Caine brought the drink to San Francisco around 1987 from the Midwest. The same year in Manhattan, the internationally recognized version of the cocktail was created by Toby Cecchini, based on a poorly described version of Cheryl Cook's creation.
The cosmopolitan is usually served in a large cocktail glass, also called a martini glass. For this reason, the drink is sometimes mistakenly categorized as a type of martini.
Mix 2 parts lemon vodka to one part triple sec combined with one part cranberry and the juice of half a lime. Cointreau or other high-quality triple sec provides a cleaner taste than cheaper triple sec, and is generally substituted in the cosmopolitan. The cranberry mainly adds colour and should not excessively dilute the drink.
A wedge of lemon or lime, or a twist of orange or lemon peel, are commonly used to garnish. Traditionally a coin sized piece of orange should be "flamed" across the top of the drink. This coats the drink with a slick of citrus oil, but also produces a flame.