Esters and phenols are organic compounds that contribute to the aroma and flavor of many beer styles. You frequently hear the terms “estery” and “phenolic” in sensory descriptions, but what exactly do these terms mean?
For starters, here are the technical definitions (which are probably only meaningful to the chemically curious):
An ester is an organic compound in which the hydrogen (H) in one of the compound’s carboxyl groups (-COOH) is replaced by another hydrocarbon.