Which flavor is primarily derived from yeast?

The flavor that is primarily derived from yeast is apple. During fermentation, yeast can produce esters and phenols, which contribute various flavors and aromas to beer. One of the common esters produced by yeast is ethyl acetate, which has a fruity aroma that often resembles apple. This is particularly evident in certain styles of beer, especially those that use ale yeast, which tends to produce more pronounced fruity esters compared to lager yeast.

While citrus, floral, and chocolate flavors can originate from hops, malt, or other ingredients used in brewing, they are not directly associated with yeast activity in the same way that apple flavors are. Citrus notes are often derived from hop varieties, floral flavors can come from the hops or from certain malts, and chocolate flavors are typically a result of roasted malts. In contrast, apple characteristics are a direct product of the fermentation process and the specific yeast used in brewing.