Glycerol of about 170 European wines was analyzed using gas chromatography−combustion−isotoperatio mass spectrometry technique. 13C/12C isotopic ratio measurements were performed tocharacterize glycerol's δ13C values of genuine wine samples from European Union wine-producingcountries. Glycerol was also successfully dosed using an internal reference, 1,5-pentanediol. Keywords: Authenticity proof; stable isotope; carbon-13; glycerol; wine; GC-C-IRMS; Botrytis cinerea