Which of the following is a sign that beer might be too warm?

Excessive foam from the tap is indeed a sign that beer might be too warm. When beer is served at temperatures that are higher than optimal, it can lead to increased carbonation release, causing excessive foaming or over carbonation when poured. This can result in a poor pouring experience and can mask the flavors of the beer.

In contrast, chill haze, which refers to a cloudy appearance that can occur when beer is chilled, is typically not related to serving temperature but rather to the proteins and polyphenols interacting with the cold. A strong aroma can be indicative of a beer’s flavorful characteristics emerging, which could sometimes be appropriate depending on the style and not necessarily a sign of warmth. A flat taste can occur for various reasons including flat beer due to a lack of carbonation, but it is not directly a sign of the beer being too warm; flat beer can also occur when beer is old or has been improperly stored.