Pisco Sour is a classic South American cocktail, originally invented in Lima, Peru, but also popular in Chile. The base liquor is pisco, a brandy produced by distilling fermented grape juice into a liquor with high alcohol content.
There is ongoing rivalry between Chile and Peru with regards to the origin of pisco. This cocktail is claimed by both countries as their national drink! The following recipe is for the Peruvian version of Pisco Sour. The Chilean version uses Chilean pisco, and excludes egg whites and bitters.
Peru pays tribute to pisco not once, but twice in a year: the first Saturday of every February is the official “Día del Pisco Sour” (Pisco Sour Day), while the fourth Sunday of every July is declared “Día del Pisco” (Pisco Day).