Which glass is used for serving an Old Fashioned cocktail?

The Old Fashioned cocktail is traditionally served in a rocks glass, also known as an Old Fashioned glass. This type of glass is short and sturdy, allowing for the muddling of ingredients like sugar and bitters when preparing the drink. The shape of the rocks glass is perfect for showcasing the cocktail's rich, amber color and facilitates the addition of ice, which enhances the drink's flavor as it chills.

Using a rocks glass also enhances the overall drinking experience, as it allows for a more intimate feel when enjoying a classic cocktail. The wider mouth of the glass enables the aromas of the bourbon and other ingredients to be easily accessible, contributing to the overall enjoyment of the drink. In contrast, the other glass types listed do not adequately fit the traditional style and presentation of an Old Fashioned.