Regan's orange bitters
Regans' Orange Bitters #6 is a brand of cocktail bitters invented in the early 1990's by Gary Regan, who based his original recipe on a recipe in Charles Baker's The Gentleman's Companion: An Exotic Drinking Book. The recipe includes orange peel, cardamom and coriander along with the classic bittering agents cinchona bark, quassia and gentian root. They are now made by the Buffalo Trace distillery.
There were two other versions,#4 was homemade and too bitter and #5 was rejected by the TTB for being potable! Regans' Orange Bitters #6 is a pale orange in color and clear. It smells of bitter oranges and honey, with a flowery topnote, but the palate is driven by an assertively peppery bitterness that cuts through the sweetness of the citrus.