176 MODERN METHODS OF TESTING MILK 



the correct amounts would be about 4 per cent, of fat 

 and 9 per cent, of solids-not-fat. This basis is prefer- 

 able to the use of a legal standard, because legal stand- 

 ards prescribe the lowest permissible amounts of fat 

 and solids-not-fat, while milk that can be regarded as 

 deserving a perfect score in composition should surely 

 be above the low amounts allowed by legal standards. 

 Some might claim that a composition of 4.5 or 5 per 

 cent, of fat content and 9.2 or 9.3 per cent, of solids- 

 not-fat should be used as representing milk of perfect 

 composition. The medium composition between this 

 high extreme and the low extreme of a legal standard 

 should appeal to one on careful thought as the wisest 

 basis for scoring the composition of milk. 



Using 4 per cent, of fat and 9 per cent, of solids- 

 not-fat as indicating the basis of a perfect score in 

 composition in market milk, the next question that 

 arises is as to how many points out of 100 shall be al- 

 lowed for a perfect score in composition. In the writ- 

 er's judgment, not less than 45 points should be al- 

 lowed for perfect composition. Then, for each one- 

 tenth of one per cent, of fat below 4 and of solids-not- 

 fat below 9, there should be a reduction of one point. 

 Thus, milk testing 3.5 per cent, of fat and 8.8 per cent, 

 of solids-not-fat would be scored 38 points on com- 

 position. 



Keeping power of milk in relation to commercial 

 testing and scoring. — The length of time milk remains 

 sweet and palatable for table use is commonly indi- 

 cated as its keeping power or quality. This is an im- 

 portant factor in estimating the commercial value of 

 market milk, since sour or unpalatable milk, or milk 



