The use of egg whites in Whiskey Sours has gone in and out of fashion over time. Jerry Thomas who published the first cocktail recipe book didn't include it in his recipe, but many of his contemporaries did. Today, whether your whiskey sour has egg white in it will depend on the bartender making it. We personally love egg white sours, but for Caged Heat, it became easier to explain what kind of cocktail it was by calling it a spicy whiskey sour even though it doesn't call for egg. We highly encourage you to use egg white, or it's vegan counterpoint aquafaba with any of our syrups if that appeals to you.