The Campari Gin Fizz is a sweet and sour cocktail that is made with gin, campari, and fresh lemon juice. To cut their sharp flavors, simple syrup and an egg white are mixed in as well (the latter of which provides a smooth, silky texture and a frothy top). Finish with club soda for the classic fizz cocktail, or leave it off and strain into a coupe glass for a Campari Gin Sour.