The Forbidden Sour is a mix of Pomegranate Flavored Liqueur, Bourbon Whiskey, Lemon Juice, and Simple Syrup. The history of the drink is unclear, but it is believed to date back to the early 1900s. The cocktail was likely created in the United States, though its exact origin is unknown. The Forbidden Sour gained popularity in the 1920s and has been a staple of American culture ever since.