What is the primary purpose of a shaker in bartending?

The primary purpose of a shaker in bartending is to mix and chill cocktails. When a shaker is used, ingredients such as spirits, juices, syrups, and other components are combined effectively through vigorous shaking. This process not only ensures that the flavors intermingle seamlessly but also incorporates ice, which cools the mixture down rapidly, creating a refreshing drink.

Shaking is a common technique for cocktails that contain ingredients which require thorough mixing, such as citrus juices or creams, as it emulates the action of stirring but with added aeration and chilling benefits. The result is a well-blended cocktail that has a smooth texture and an inviting, chilled temperature, which is crucial for the overall drinking experience.

The other options, while related to the bartending process, do not encapsulate the main function of a shaker. Straining is typically done after shaking to separate the liquid from the ice, measuring is a distinct process often accomplished with jiggers, and icing cocktails is more about cooling rather than the comprehensive mixing aspect that the shaker provides.