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

Frosting beer glasses with ice crystals is never recommended because it can negatively affect the beer's aroma and flavor. When glasses are overly chilled, it can suppress the aromatic compounds that contribute significantly to the overall experience of the beer. Many styles of beer, particularly those with complex aromas like IPAs or Belgian ales, benefit from a slightly warmer serving temperature, which allows the flavors and aromas to be fully expressed.

Conversely, warming with hot water, wiping with a clean cloth, and rinsing with cold water each serve specific purposes in preparation. Warming with hot water can be appropriate for certain styles that benefit from higher temperatures, while wiping with a clean cloth ensures the glass is free from dust and oils that could interfere with the beer's appearance and aroma. Rinsing with cold water can help remove dust or residues and cool the glass without causing ice crystals that negatively impact the beer's characteristics.