Which tool is commonly used to slice garnishes in bartending?

The tool commonly used to slice garnishes in bartending is a knife. A knife is versatile and allows bartenders to cut fruits or vegetables into various shapes and sizes, depending on the cocktail being prepared. It can easily create slices, wedges, or twists that enhance the presentation of the drinks. Bartenders often rely on their knife skills to achieve precise cuts, which are essential for garnishing cocktails not only for aesthetic appeal but also to release essential oils and flavors from the garnishes.

While other tools listed have specific uses, they do not primarily serve the same broad function as a knife in the context of slicing garnishes. A peeler is typically used for removing the skin from fruits and vegetables rather than for slicing. A zester is designed for removing the outer layer or zest of citrus fruits to add flavor, while a mandoline is primarily for creating uniform slices and may not be practical in a busy bar environment. Therefore, a knife stands out as the most appropriate and commonly used tool for slicing garnishes in bartending.