MANUFACTURE OF STARTERS: PRODUCTION OF FROZEN CONCENTRATED CHEESE STARTERS BY DIFFUSION CULTURE

Diffusion culture allows the production of concentrated cheese starter without centrifugation principally by removing inhibitory lactate from fermentations. Laboratory scale fermentation systems are described which remove lactate via a diffusion membrane. Single and mixed strain cultures were grown to concentrations of 10¹¹/ml in an enzyme digest of skimmed milk supplemented with yeast extract. The present stage system is capable of producing at least half the annual bulk starter requirements of a creamery processing 100,000 gal of milk/day. Concentrated cultures were harvested in hypodermic syringes and as frozen granules. Concentrates were tested for purity and activity and suitable ones used in a commercial cheesemaking trial which produced a high proportion of extra selected grade Cheddar cheese.