γ-Glu-Phe, γ-Glu-Met and γ-Glu-Val, are identified in sourdough by liquid chromatography-tandem mass spectrometry in MRM mode. γ-Glutamyl dipeptides are found in higher concentrations in sourdough fermented with L. reuteri when compared to the chemically acidified controls. Proteolysis is an important factor for generation of γ-glutamyl dipeptides. Sensory evaluation of bread reveals that sourdough bread with higher concentrations of γ-glutamyl dipeptides ranks higher with respect to the taste intensity when compared to regular bread and type I sourdough bread. Sourdough breads fermented with L. reuteri LTH5448 and L. reuteri 100-23 differ with respect to the intensity of the salty taste; this difference corresponds to a different concentration of γ-glutamyl dipeptides.