What spices are to a chef, bitters are to a bartender. Gone are the days when a lonely bottle of Angostura bitters held court behind the bar. A cocktail renaissance has swept across the globe, inspiring in bartenders and their thirsty patrons a new fascination with the ingredients, techniques, and traditions that make a cocktail so special; and few ingredients have as rich a history or serve as fundamental a role in our beverage heritage as bitters.