Regans' Orange Bitters #6 is a brand of cocktail bitters, invented in the early 1990s by Gary Regan, a bartender who helped nurture the cocktail movement. The recipe includes orange peel, cardamom, and coriander along with the classic bittering agents: cinchona bark, quassia, and gentian root.

If you're looking for a perfectly balanced bitter, look no further. Citrus flavors and aromas are decidedly forward but not overpowering, allowing them to play well with nearly any spirit (including whiskey, rum, brandy, gin, and vodka), as well as with other bitters.