Analysis of the key odorants of tempeh after different fermentation time and after frying, revealed several groups of sensory important compounds. These groups comprised of nitrogen containing compounds, 2-acetyl-1-pyrroline and pyrazines, however, out of the 12 detected pyrazines only two were of major significance. Another important group was aldehydes, formed in lipoxygenase pathways and autooxidation, the amount of aldehydes increased significantly during the frying process, methionine degradation of sulfur compounds (dimethyltrisulfide) and also 1-octene-3-one. Characterization of key odorants using FD was generally in good accordance with OAV method results. A vast amount of identified peaks by GC × GC-ToFMS, indicate a need for sensory guided (GC–O) analysis, in detection of volatiles important for the flavour of tempeh and also other food products.