What additional ingredient is mixed with Irish whiskey in an Irish Coffee?

In an Irish Coffee, half and half is the additional ingredient mixed with Irish whiskey. The drink combines freshly brewed hot coffee with Irish whiskey, and the richness of half and half contributes to its creamy texture. This combination enhances the smoothness of the whiskey and balances the robustness of the coffee with a layer of richness.

The correct mixing of these ingredients is fundamental to achieving the iconic flavor profile of an Irish Coffee. The drink is typically topped with whipped cream, which, along with the half and half, provides a luxurious mouthfeel and visually appealing presentation. This specific combination is key to the authenticity and enjoyment of an Irish Coffee, making half and half the essential ingredient that complements the whiskey perfectly. Other ingredients listed do not traditionally belong in an Irish Coffee, as they would alter the fundamental nature of this classic beverage.