Black Walnut Bitters bring a robust nut flavor to the spice rack behind your bar. The best bartenders and master-Mixologists know the secret to a happy customer is the magic that goes into every creation. That’s why they choose Fee Brothers. 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.