ABSTRACTShanxi aged vinegar differs from other vinegars in that it has a unique thermal process (6 days at 85°C) which creates its typical flavour. The present study evaluated the key aroma compounds of Shanxi aged vinegar made from tartary buckwheat by gas chromatography–olfactometry–mass spectrometry. The influence of the thermal processing on product aroma was also studied. A total of 45 compounds were detected of which 24 were correctly identified while 21 were tentatively identified: the remaining six were unknown. Of the 45 compounds detected, 13 have not been previously reported in other vinegars. Most of the aroma compounds identified increased significantly during the first 3 days of heating and then decreased from the fourth day onwards. The changes may have resulted from different kinds of reactions, such as the Maillard reaction and other associated reactions such as degradation of amino acids. This study would be helpful for optimizing the processing conditions of Shanxi aged vinegar. Copyright © 2011 John Wiley & Sons, Ltd.