What is the correct glass type for serving a Whiskey Sour?

The correct choice is Sour Glass for serving a Whiskey Sour because this type of glass is specifically designed to accommodate cocktails that contain citrus juice, which is a key ingredient in a Whiskey Sour. The wide bowl shape allows for proper mixing and serves to enhance the drink's presentation, making it visually appealing while also allowing for a generous surface area for garnishes such as cherries or citrus slices. This is ideal for a drink that is both tart and spirit-forward, as it balances the flavors and provides an enjoyable drinking experience.

While a Cocktail Glass, Champagne Flute, and Collins Glass serve distinct purposes for other beverages, they do not provide the optimal characteristics needed for a Whiskey Sour. The Cocktail Glass, for example, is better suited for serving straight-up drinks without ice, while a Champagne Flute is designed to maintain carbonation and showcase the bubbles in sparkling wines. The Collins Glass, often used for longer drinks and cocktails served with ice, doesn't complement the Whiskey Sour's profile as effectively as the Sour Glass does. Thus, the Sour Glass is the ideal choice for this cocktail.