 The pisco sour has three different methods of preparation . The Peruvian pisco sour cocktail is made by mixing Peruvian pisco with Key lime juice , simple syrup , egg white , Angostura bitters ( for garnish ) , and ice cubes . The Chilean pisco sour cocktail is made by mixing Chilean Pisco with Pica lime juice , powdered sugar , and ice cubes . Daniel Joelson , a food writer and critic , contends that the major difference between both pisco sour versions " is that Peruvians generally include egg whites , while Chileans do not . " The version from the International Bartenders Association , which lists the pisco sour among its " New Era Drinks , " is similar to the Peruvian version , but with the difference that it uses lemon juice , instead of lime juice , and does not distinguish between the two different types of pisco . 
