The metabolic interactions among the dominant Greek traditional wheat sourdough species Lactobacillus sanfranciscensis and Saccharomyces cerevisiae and the complementary species Lactobacillus brevis, Lactobacillus paralimentarius, Pediococcus pentosaceus and Weissella cibaria were examined. Their effect on the sensory properties of bread was evaluated as well. Wheat sourdough bread making was carried out according to a three-stage traditional procedure adjusted to semi-industrial scale. L. sanfranciscensis and S. cerevisiae were used as starter cultures either as such or in combination with L. brevis, L. paralimentarius, P. pentosaceus and W. cibaria. The determination of the metabolic products in sourdough samples was performed by HPLC analysis. L. brevis, W. cibaria and P. pentosaceus had basically no effect either on growth of the basal microflora or on the total metabolite production. On the other hand, L. paralimentarius seemed to have a negative effect on L. sanfranciscensis growth. All sourdough breads produced exhibited worthy organoleptic properties. Bread made with S. cerevisiae, L. sanfranciscensis and L. brevis ranked first in the sensory evaluation. The qualitative and quantitative differences observed in the metabolites ' profiles of the sourdoughs prepared with the different combinations of starters could not be correlated with the sensorial analysis of the respective breads produced. (c) 2005 Elsevier Ltd. All rights reserved.