2j8 SCIENCE AND PRACTICE OF CHEESE-MAKING 



follows : "Standard whole-milk or full-cream cheese 

 contains, in the water-free substance, not less than 

 50 per cent butter-fat." There has been wide- 

 spread and needless misunderstanding in regard to 

 the meaning of this standard. Many have inter- 

 preted it as meaning that normal or whole-milk 

 cheese must contain 50 per cent of fat. The law 

 does not say that at all, but that 50 per cent, not of 

 the cheese, but of its water-free substance (cheese- 

 solids) must consist of butter- fat. This can easily 

 be made clear by giving a specific illustration of 

 its application, and, for this purpose, we take a ched- 

 dar cheese of average composition,, containing: 



Water 36.80 per cent. 



Water-free substance 63.20 



Consisting of (lOOTOO) 



Fat 33.75 



Proteins. . .23.75 



Salts, etc... 5.70 



63.20 



In order to apply the standard to any cheese, we 

 need to know only the percentages of water and 

 of fat. One then proceeds as follows : Subtract 

 the percentage of water from 100, which gives the 

 cheese-solids or water-free substance, and then 

 divide the percentage of fat in cheese by the per- 

 centage of water-free substance. Expressed in out- 

 line, the statement becomes: (i) 100 minus per cent 

 of water per cent of water- free substance; (2) per 

 cent . of fat-v-per cent of water-free substance= 

 per cent of fat in water-free substance. Example: 

 (i) 100 36.80 (per cent of water in cheese)= 

 63.20 (water-free substance in cheese). (2) 33.75 

 (per cent of fat in cheese)-f-63. 20=53.4, which is the 



