Mesophilic and Thermophilic Cultures Used in Traditional Cheesemaking

Most cheese varieties require acidification of milk by a select group of bacteria called starters. They ferment lactose to lactic acid and in so doing aid the cheesemaker in developing the desired texture as well as acidity of the cheese. However, while other microorganisms play the major role in flavor development of cheese, it is the starter that sets the stage for quality cheese manufacture. Starters were traditionally derived from the native microflora of the milk, but this practice is almost unheard of today. With the advent of better hygienic milking practices and industrialized cheesemaking, there was a need for more uniformity and reliable sources of the starter culture. Today's starters are produced by companies specializing in their production as well as in the development of new strains for cheesemakers. The choice of starter for the manufacture of a specific cheese is dictated by the cheesemaking protocol, but it is also governed by the need to produce cheese with desired physical attributes. The properties of the starter that make it possible to do so help drive innovation in developing new potential choices in starter cultures. Indeed, the demands for predictable and reliable rates and extent of acidification of milk for cheesemaking and flavor development are as key for successful cheesemaking today with artisanal cheesemakers as they are for larger, more industrial-scale cheesemakers.