Phenols

phenols. (fee'-nolz)

    Volatiles found in small quantities in beer. Higher concentrations, due to the brewing water, infection of the wort by bacteria or wild yeasts, cleaning agents, or crown and can linings, impart off-flavors characterized as phenolic, medicinal, or pharmaceutical. Sixty volatile phenolic compounds are present in beer, and their concentration is greater in dark beers than in pale beers.