CREAM RIPENING 247 



fore contains 100 25 = 75 per cent serum. When the per 

 cent acid in the cream is known, the per cent acid in the serum 

 is calculated by dividing it by the per cent serum and multiply- 

 ing the quotient by 100. The per cent acid in the serum, of 

 cream testing 25 per cent fat and .6 per cent acid is as follows : 



-y~-X 100 = .8 per cent acid. The above calculation shows that 



the standard amount of acid in the serum should be .8 per 

 cent. On the above basis the standard per cent acid for cream 

 of any richness may readily be calculated, by deducting the 

 per cent fat in the cream from 100, multiplying the difference by 

 .8 and dividing the product by 100. 



Example : Cream tests 33% fat. To what per cent acid should 

 it be ripened? 



100 33 = 67; 67 * ' 8 = .536 per cent acid. 



1UU 



For the convenience of the operator Table 42 has been 

 devised which shows the desired degree of ripeness in per 

 cent acidity, number of cubic centimeters of one-tenth normal 

 alkali solution required as per Mann's test and degree acidity as 

 per Soxhlet-Henkel method. 



In using this table the butter maker and student should 

 bear in mind that it was devised only as a guide applicable 

 and convenient under fairly normal conditions. Its value is 

 limited by the fact that its figures need modification and read- 

 justment under a great variety of conditions, and at best should 

 be applied only to cream that is of good quality and sweet 

 when it reaches the creamery and to butter intended for imme- 

 diate consumption. 



Overripened Cream. The overripening of cream is det- 

 rimental to the flavor, texture and keeping quality of butter. 

 In overripened cream the most favorable acid bacteria have 

 gone beyond their maximum stage of activity, the excessive 

 degree of acidity, their own product, is detrimental to their 

 further development, they become weakened, degenerate and 

 give way to other fermentations, less desirable and usually 

 harmful to the flavor of the butter. 



