Abstract: A method for the preparation of naturally stabilized, thick bodied, fermented milk products by fermentation is described. Mixed cultures of milk fermenting, non-slime, lactic acid producing bacteria and slime producing Streptococcus lactis, Streptococcus cremoris or mixtures thereof having the thickening characteristics in milk of Streptococcus cremoris NRRL-B-12,361, 12,362 or 12,363 are used, preferably in addition with a diacetyl producing bacterium for flavor. The fermented milk products are thick bodied without any ropiness or sliminess and are stable to separation of whey from curd upon storage at refrigeration temperatures, with little or no added stabilizing agents such as gums and starches or thickening agents such as added non-fat milk solids. The preferred product is a thick bodied buttermilk.

Abstract: Naturally stabilized fermented milk products are prepared with a concentrate of Streptococcus thermophilus cells that produce a stabilizer in situ when cultured in milk. The concentrate is obtained by culturing the stabilizer-producing Streptococcus thermophilus in a growth medium including milk solids to obtain at least about 10.sup.8 cells per ml. The growth medium preferably contains maltose, sucrose, fructose or lactose which enhances stabilizer formation.

Abstract: Storage stable, lyophilized, acid producing bacteria, such as lactic acid bacteria, are prepared by lyophilizing the bacteria in the presence of at least 5% by weight of the bacteria of a basic organic or inorganic buffering agent, preferably an alkali metal salt of glycerophosphate, to provide lyophilized bacteria containing less than 5% by weight water, and sealing the lyophilized bacteria in a container while in a vacuum or surrounded by a gaseous atmosphere substantially free of oxygen, preferably argon which is essentially free of oxygen.

Abstract: A biologically concentrated Streptococcus diacetylactis is used to develop in creamed cottage cheese a desirable diacetyl flavor and aroma when creamed cottage cheese is stored at refrigeration temperatures. The biologically concentrated Streptococcus diacetylactis is prepared without mechanical concentration by growing Streptococcus diacetylactis on a special media to produce at least about 10.sup.9 cells per ml.

Abstract: A novel mutant strain Streptococcus diacetilactis NRRL-B-8177 which is particularly adapted for the preparation of creamed Cottage cheese without fermentation (or prior incubation) of the creaming mixture or dressing is described. This strain produces about one-half of the acid produced by S. diacetilactis 18-16 which is regarded as the best bacterium that is commercially available for use in Cottage cheese. Improved flavor and prophylaxis against spoilage bacteria of the dressed Cottage cheese is preferably provided by blending a concentrate of the Streptococcus diacetilactis NRRL-B-8177 cells with a creaming mixture at less than about 50.degree. F. (10.degree. C.) and then mixing the cold cream mixture with dry Cottage cheese curd cooled to less than about 50.degree. F. and maintaining the temperature at less than about 50.degree. F.

Abstract: Frozen compositions of lactic acid producing bacteria which incorporate an alkali metal salt of glycerophosphoric acid are described. These salts reduce damage to the bacteria upon freezing and storage which with certain bacteria is evidenced by enhanced lactic acid forming activity upon thawing and use of the compositions as fermented dairy product starter cultures.

Abstract: A method for testing milk to determine its ability to be fermented by bacteria in order to produce cheese, cottage cheese and the like is described. The method utilizes a colorimetric oxidation-reduction dye which rapidly changes color when the milk is readily fermentable.