Which of the following is NEVER recommended as a preparation for beer glasses?

Frosted with ice crystals is never recommended as a preparation for beer glasses because this method can negatively impact the beer's flavor and aroma. When a glass is frosted, the temperature can be so low that it numbs the palate, making it difficult for drinkers to fully appreciate the beer's intended characteristics. Additionally, it can cause condensation to form on the glass, which may dilute the beer when it spills or drips back into the glass.

In contrast, other methods like air drying, lightly chilling, and serving at room temperature can enhance the drinking experience. Air drying allows any residual water to evaporate, leaving the glass clean and ready. Lightly chilled glasses can help maintain a beer's temperature and flavor profile, while serving at room temperature is appropriate for many styles of beer, allowing their aromas and flavors to fully unfold. Thus, frosting a glass is not aligned with best practices for beer service.