Cointreau has been made in Angers since 1849 from a blend of sweet and bitter orange peels, distilled rather than macerated — which is why it stays clear and tastes of orange oil rather than orange syrup. It is the backbone of a proper Margarita, a Sidecar, and a Cosmopolitan, and the difference between it and generic triple sec is immediately obvious in a glass. The 375ml is a sensible size for a home bar that doesn't run through it quickly.