What is a key ingredient in a Starbucks Doubleshot on Ice?

In a Starbucks Doubleshot on Ice, espresso is a key ingredient because it serves as the base for this beverage. The Doubleshot on Ice is primarily made with two shots of espresso, which contributes to its bold coffee flavor and rich caffeine content. The espresso is combined with ice and typically includes a splash of milk, making it a refreshing drink that highlights the coffee’s taste while also providing a creamy texture. Other flavors like vanilla or a sweetener may be added to enhance the drink, but the espresso is essential as it defines the drink’s character.

While milk is commonly involved in the drink, it's the espresso's presence that is central to creating a Doubleshot on Ice. The other options, such as matcha and caramel, are not foundational components of this specific drink, and their absence would not change the essential nature of a Doubleshot on Ice.