Which of the following is a sign of a "beer clean" glass?

A "beer clean" glass is characterized by several important features that ensure optimal performance for serving and enjoying beer. One of the primary indicators of a beer clean glass is that water sheets and runs off rather than forming drips. This quality is crucial because it indicates that the surface has been properly cleaned and is free of residues such as soap, oil, or grease, which can interfere with the beer's head retention and overall presentation.

When water sheets off a glass, it shows that the surface tension is optimal for beer, allowing for a proper head to form when beer is poured. This not only enhances the visual appeal of the beer but also affects the aroma and flavor, as a good head traps volatile compounds that contribute to the overall sensory experience.

In contrast, other options signify issues with cleanliness. A glassy and shiny surface, while aesthetically pleasing, does not inherently mean that the glass is clean. The presence of bubbles when washed suggests residual detergent or oils, which would compromise the glass's cleanliness and the beer's quality. Lastly, a cloudy appearance when filled indicates that there are likely impurities present, which can negatively affect the beer’s flavor and clarity. Thus, the attribute of water sheeting off is the definitive sign of a properly prepared beer clean