What sensory aspect is primarily affected by the temperature of beer?

The aroma of beer is significantly influenced by its temperature, making it the primary sensory aspect affected. Beer releases different volatile compounds that contribute to its aromatic profile, and these compounds behave differently at various temperatures. When beer is served too cold, some of the aromatic compounds can be suppressed, resulting in a muted aroma that obscures important scent characteristics. Conversely, as the temperature rises, these volatile compounds are more readily released into the air, enhancing the beer's aroma and allowing the drinker to perceive the full breadth of its fragrant notes.

While appearance (such as color and head retention), sourness (which is related to flavor perception), and clarity (which relates to particulate matter suspended in the beer) are important aspects of beer, they are not as directly influenced by temperature as aroma is. Temperature does play a role in overall perception, but aroma is the most sensitive to it and can significantly change the experience of the beer.