Mixologist julie reiner (of flatiron lounge in new york city) created this drink after returning home from a tour of peruvian pisco distilleries. Its a wonderful way to show off your favorite bottle of pisco, with a well-rounded flavor that even pisco neophytes can appreciate. The original cuzco recipe calls for aperol as the bitter citrus apritif. Wed stick with that or another not-too-bitter brand; something like campari would be too bitter, and overpower the more delicate flavors of pisco and kirsch. Reiners recipe calls for the kirsch to be used as a rinse that is, swirled around the glass and then discarded. Since its such a small amount, you could substitute maraschino liqueur for the kirsch. Maraschino is a little funkier than kirsch, but it works well with the aromatics of the pisco and grapefruit.