Abstract: 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.

Abstract: A freeze-dried sour dough French bread starter culture, or baking additive for other purposes, is prepared by inoculating an unsterilized and unpasteurized flour-water-salt suspension with a natural mother or starter sponge containing numerous naturally occurring and closely related strains of Lactobacillus sanfrancisco, and also containing substantial levels of the natural fermentations acids, lactic and acetic; incubating said mixture at about 82.degree. F. until a specified acidity level is reached corresponding to about 2.times.10.sup.9 viable bacteria per gram; cooling to about 55.degree. F., and adding stabilizers compatible with the flour system, in particular certain disaccharides; freezing under moderate conditions (-10.degree. to -25.degree. F.) without first separating the cells from the flour medium; followed by conventional freeze-drying in vacuo (vacuum of approximately 50 to 200 microns) to a moisture content in the final product of about 2%.

Abstract: A freeze-dried sour dough French bread starter culture, or baking additive is prepared by inoculating an unsterilized and unpasteurized flour-water-salt suspension with a natural mother or starter sponge containing strains of Lactobacillus sanfrancisco, and also containing substantial levels of the natural fermentations acids, lactic and acetic; incubating said mixture at about 82.degree. F. until a specified acidity level is reached corresponding to about 2 .times. 10.sup.9 viable bacteria per gram; cooling to about 55.degree. F. and adding stabilizers compatible with the flour system, freezing under moderate conditions (-10.degree. to -25.degree. F.) without first separating the cells from the flour medium; followed by freeze-drying in vacuo to a moisture content in the final product of about 2%.