FEE BROTHERS AZTEC CHOCOLATE COCKTAIL BITTERS. Tasting Notes: A blend of sweet chocolate, with a hint of heat and spice. A must-have for the creative bartender. Fee Brothers have been one of only two mainstays in the cocktail bitters world for over 100 continuous years. Opened in 1863, Fee Brothers of Rochester, New York, is in its fourth generation of manufacturing top quality bitters.