Chartreuse is a French liqueur made by Carthusian Monks since the 1740s, known for its unique history, complex flavor, and the secrecy surrounding its production. The liqueur is named after the Grande Chartreuse monastery located in the Chartreuse Mountains near Grenoble, France, which is the head monastery of the Carthusian order. The recipe for Chartreuse is said to be based on an ancient manuscript gifted to the monks in 1605, which contained a formula for an "elixir of long life."

Chartreuse is distinctive for its use of over 130 herbal extracts, and the exact recipe is a closely guarded secret known to only a few monks. The liqueur comes in several varieties, with Green Chartreuse and Yellow Chartreuse being the most widely known. Green Chartreuse (55% alcohol by volume) is notable for its bright green color and strong herbal flavor, making it the only liqueur in the world with a completely natural green color. Yellow Chartreuse (40% alcohol by volume) is milder and sweeter, with a pale yellow color, attributed to the addition of honey and a slightly lower alcohol content.

The production process involves macerating the selected herbs and plants in a base alcohol, followed by distillation and aging in oak casks. This process contributes to the liqueur's complex flavors and aromas, which can include notes of citrus, mint, spice, and floral undertones, among others.

Chartreuse is enjoyed in various ways: neat, on the rocks, with water, or as an ingredient in cocktails. Its unique flavor profile allows it to add depth and complexity to a wide range of drinks. Due to its strong and distinctive taste, it is often used as a digestif, consumed after a meal to aid digestion.

In addition to Green and Yellow Chartreuse, there are also limited editions and variations produced by the monks, including Chartreuse V.E.P. (Vieillissement Exceptionnellement Prolongé), which is aged for an extended period and offers an even more complex flavor profile. Despite its commercial success, the production of Chartreuse remains a monastic enterprise, with profits supporting the monastic community and their charitable endeavors.