178 Dairy Bacteriology. 



aroma. Texture registers more accurately the physical 

 nature of the ripening. The cheese should not be curdy 

 and harsh, but should yield quite readily to pressure under 

 the thumb, becoming on manipulation waxy and plastic 

 instead of crumbly or mealy. Body refers to the openness 

 or closeness of the curd particles, a close, compact mass 

 being most desirable. The color of cheese should be even, 

 not wavy, streaked or bleached. 



For a cheese to possess all of these characteristics in an 

 optimum degree is to be perfect in every respect a condi- 

 tion that is rarely reached. 



So many factors influence this condition that the problem 

 of making a perfect cheese becomes exceedingly difficult. 

 Not only must the quality of the milk the raw material 

 to be used in the manufacture be perfectly satisfactory, 

 but the factory management while the curds are in the vat 

 demands great skill and careful attention; and finally, the 

 long period of curing in which variation in temperature 

 or moisture conditions may seriously affect the quality, 

 all of these stages, more or less critical, must be successfully 

 gone through, before the product reaches its highest state 

 of development. 



It is of course true that many phases of this complex 

 series of processes have no direct relation to bacteria, yet 

 it frequently happens that the result attained is influ- 

 enced at some preceding stage by the action of bac- 

 teria in one way or another. Thus the influence of the 

 acidity developed in the curds is felt throughout the whole 

 life of the cheese, an over-development of lactic-acid bac- 

 teria producing a sour condition that leaves its impress not 

 only on flavor but texture. An insufficient development 

 of acid fails to soften the curd-particles so as to permit of 



