What is considered an unacceptable way to serve beer in terms of glass condition?

A glass with a thin ring of gunk at the liquid level is unacceptable because it indicates that the glass is not properly cleaned. Any residue left in a glass can negatively impact the beer's flavor and aroma, as well as diminish the overall drinking experience. Clean glassware is essential for showcasing the beer’s color, carbonation, and head retention. Furthermore, contaminants can lead to off-flavors and aromas that detract from the beer's intended character.

While a completely dry glass is preferred, as moisture can dilute the beer's aroma and form a less ideal head, it is not as critical as ensuring that the glass is free from residues or contaminants. A sparkling clean glass is the ideal scenario, and even a frosted glass can be acceptable in certain contexts, although it may not allow for optimal aroma appreciation. The presence of gunk, however, fundamentally undermines the quality of the beer being served.