1-(2-Furyl)propane-1,2-diol, the ultimate product of furfural metabolism, was detected in beer for the first time. The diol was very stable and its concentration remained unchanged during storage of the beer in a bottle. The diol could not be detected in wort prior to fermentation. During the main fermentation, the diol increased to a level of 30 ppb, which was maintained throughout the subsequent secondary fermentation (lagering) process. The results of an analysis of the diol in commercial beer samples are also discussed.