What is a common sign of over-carbonated beer when poured?

Excessive head foam is a clear indicator of over-carbonated beer when poured. When beer is over-carbonated, the high levels of dissolved carbon dioxide rapidly escape as the beer is poured, resulting in an abundance of foam. This excessive head can create an unpleasant drinking experience, as it takes longer to settle and might mask the beer's aromas and flavors. Proper carbonation is essential for maintaining a balanced mouthfeel and enhancing the beer’s overall profile, and when there is too much carbonation, it disrupts this balance.

The other signs are not typically associated with over-carbonation. A flat beer, for instance, would suggest under-carbonation rather than over. An unpleasant odor can stem from several different issues, including poor fermentation or contamination, rather than carbonation levels. Lastly, a pale color relates to the beer's ingredients and brewing process, not its carbonation status.