(n.) Invented by Carthusian Monks in the early-16th century for medicinal purposes, Chartreuse is one of the earliest-known herbal liqueurs. There are two versions: the 110-proof green, which has more spice and pepper notes, and the 80-proof yellow, which skews sweeter and more mellow. The exact recipes are kept secret by the monks, but more than 130 herbs, plants and botanicals are said to be used to create the vividly-hued spirits, which are sweetened with sugar and aged in oak casks for five years. Premium versions, which have been aged for 12 years, bear the V.E.P. label (Viellement Exceptionnellement Prolongé) and are worth searching out.