What flavoring ingredient is used in the Old Fashioned cocktail?

In the Old Fashioned cocktail, orange essence is a key flavoring ingredient. Traditionally, the drink is made with bourbon or rye whiskey, muddled sugar (often simple syrup), and bitters. The addition of an orange peel or twist provides a citrus aroma and flavor that enhances the overall profile of the drink. The oils released from the orange peel during preparation give the cocktail its distinct character, balancing the sweetness and bitterness present in the drink.

While lemon is commonly used in many cocktails to add acidity, it is not a traditional element of the Old Fashioned. Simple syrup is used to sweeten the drink, but it does not contribute a flavor essence in the same way that the fragrant oils from the orange do. Ginger has its own unique flavor that is not associated with the classic Old Fashioned. Hence, orange essence stands out as the correct ingredient that defines and elevates the flavor of this timeless cocktail.