Fee Brothers Aztec Black Walnut is from Fee Brothers, a family-owned company founded in 1863 in New York. Fee Brothers survived Prohibition by using glycerin as an alternative to alcohol to make bitters. Inspired by bartenders, Fee Brothers Black Walnut is the first walnut-flavored bitters ever made. A sweetening and bittering agent, Fee Brothers Black Walnut is nutty and spicy. Superb in a Manhattan or a Flip Cocktail.