Which mixing method should be utilized for powdered ingredients?

The stirring method is the most appropriate choice for mixing powdered ingredients because it allows for gentle incorporation, ensuring that the powders are evenly distributed throughout the liquid without causing aeration. This method is particularly useful for ingredients such as powdered sugar or cocoa, which can easily clump together if subjected to vigorous shaking or blending. Stirring also helps to maintain the desired texture and consistency of the drink, which is essential in bartending as it can influence the overall flavor and presentation.

On the other hand, shaking can introduce air into the mixture and may not adequately dissolve the powders, while blending is typically reserved for larger ingredients or when a smoother texture is required, such as in smoothies. Layering is primarily used for drinks that are meant to have distinct layers, which isn't suitable for powdered ingredients that need to be fully integrated into a liquid.