 A pisco sour is a cocktail typical of South American cuisine . The drink 's name comes from pisco , which is its base liquor , and the cocktail term sour , in reference to sour citrus juice and sweetener components . The Peruvian pisco sour uses Peruvian pisco as the base liquor and adds Key lime ( or lemon ) juice , syrup , ice , egg white , and Angostura bitters . The Chilean version is similar , but uses Chilean pisco and pica lime , and excludes the bitters and egg white . Other variants of the cocktail include those created with fruits like pineapple or plants such as coca leaves . 
