A spray-dried flour culture product is prepared by seeding a flour-water-salt suspension with natural mother or starter sponge containing strains of Lactobacillus sanfrancisco and Torulopsis holmii, incubating and holding said culture under prescribed conditions and spray-drying to yield a free flowing powder. Although the two microorganisms are virtually destroyed during spray drying, the present product contains a unique growth-promoting substance advantageous for use with prior art viable freeze-dried flour cultures as well as a useful amount of residual acidity.
