 Considerable variations exist in the pisco used in the cocktails . According to food and wine expert Mark Spivak , the difference is in the way both beverages are produced ; whereas " Chilean pisco is mass @-@ produced " , the Peruvian version " is made in small batches . " Cocktail historian Andrew Bohrer focuses his comparison on taste , claiming that " [ i ] n Peru , pisco is made in a pot still , distilled to proof , and un @-@ aged ; it is very similar to <unk> . In Chile , pisco is made in a column still and aged in wood ; it is similar to a very light cognac . " Chilean <unk> Patricio Tapia adds that while Chilean pisco producers usually mix vine stocks , Peruvian producers have specific pisco types that use the aromatic qualities of vines such as Yellow Muscat and Italia . Tapia concludes this is why Peruvian pisco bottles denote their vintage year and the Chilean versions do not . 
