What citrus fruit is often expressed over an Old Fashioned cocktail for added flavor?

The Old Fashioned cocktail traditionally features orange as a key flavor component. When preparing this classic drink, bartenders often express the oils from the orange peel over the drink, which enhances the overall aroma and adds a subtle sweetness that complements the bourbon or rye whiskey base. This aromatic quality is crucial to the cocktail's profile, as it balances the richness of the spirits with the citrus notes.

While other citrus fruits such as lemon and lime can be used in various cocktails, they do not typically align with the traditional taste profile of the Old Fashioned. Grapefruit, while aromatic and flavorful, is also not a standard garnish or flavor enhancer for this specific drink. The use of orange underscores its role in crafting a well-balanced and aromatic Old Fashioned.