What is the purpose of the "double dunk" technique when rinsing a glass?

The "double dunk" technique is specifically designed to enhance head retention when pouring beer. This method involves rinsing the glass twice, which helps to create a consistent environment inside the glass, ensuring it is clean and free of any residual oils or film that could negatively impact the formation of the head. Proper head retention is essential for trapping aromas and allowing for the overall enjoyment of the beer, as the head plays a critical role in the beer's presentation and aroma.

While other choices may suggest benefits related to cleanliness or efficiency, they do not directly relate to the primary function of the double dunk technique, which centers on improving the experience of consuming the beer by maintaining its structural integrity during the pour.