Volatile Compounds and the Changes in Their Concentration Levels during Storage in Beers Containing Varying Malt Concentrations

Volatile compounds in beers brewed with different amounts of malt were analyzed by using the stir bar sorptive extraction-gas chromatography-mass spectrometry method. We identified 90 compounds-25 esters, 17 terpenes, 14 alcohols, 11 acids, 6 furans, 6 aroma compounds, 5 carbonyls, and other compounds. An analysis of aged beer suggested that the concentration levels of stale flavor compounds-beta-damascenone, gamma-nonalactone, ethyl cinnamate, and 2-methoxy-4-vinylphenol-in nonmalt beer were different from those in all-malt and standard beer. Additionally, concentrations of these compounds did not increase during storage in most nonmalt beer analyzed in this study. Nerolidol may be a good marker candidate regardless of the malt content.