A pisco sour is an alcoholic cocktail of Peruvian origin that is typical of the cuisines from Peru and Chile. 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. A pisco sour is an alcoholic cocktail of Peruvian origin that is typical of the cuisines from Peru and Chile. The drink's name comes from pisco, which is its base liquor, and the cocktail term sour, Pisco is a Peruvian grape distillate and it is the basis of Peru's best-known alcoholic beverages.