At Havana, Cuba’s El Floridita bar, this special daiquiri was a usual order of author Ernest Hemingway. It was created by then-head bartender Constantino Ribalaigua Vert, who was known as “Constante” to regulars and “El Rey de los Cocteleros” (“The Cocktail King”) to locals. Legend has it that Hemingway requested a daiquiri with less sugar and more rum, and Vert obliged by doubling the rum, adding grapefruit juice to the customary lime, and swapping out the simple syrup for maraschino liqueur. And that’s how the Hemingway Daiquiri, or the Papa Doble (Papa was a nickname for Hemingway, and “doble” referred to the double jigger of rum), was born. While we prefer including simple syrup to balance out the tartness, feel free to omit if you want to stay true to Hemingway's original version.