Amargo Chuncho Bitters 75ml. The Amargo Chuncho, or Chuncho Bitters, was so named after the tribe of the Amazonian Indians who resisted the Spanish conquerors. It is the authentic Peruvian bitter and the only one for an authentic Pisco Sour. Chuncho is a complex and balanced combination, with over 30 different fruit peels, spices and flowers from the forests of Peru. This combination is left in barrels for 6 months to mature before bottling. Its most common use is for cocktails but it is also used in cooking. Despite the small dosage we use in cocktails, the bitters give a different profile and help all the ingredients to "tie" together.