The Pisco Sour belongs to the Sour category of drinks. This category are drinks that contain a liquor with lemon or lime juice. These drinks tend to be appetizing, tart, and zesty. The lemon juice adds the sourness, which the simple syrup tames. They can be made with almost any spirit, the original and the most popular version is the Whisky Sour dating back to the 1880s.  The Pisco Sour is the South American version of the whisky cocktail. Pisco is a grape brandy from South America, and the two major producers are Chile and Peru.