ILLINOIS DAIRYMEN'S ASSOCIATION. 175 



add four or five drops of the phenothalen indicator. Having 

 filled the cylinder to the top or 100 cc mark with the 50th 

 normal alkali solution, begin pouring slowly into the cream 

 sample, mixing with a rotary motion of the hand or stirring- 

 with a glass rod until there is a pink color noticeable, which does 

 not disappear by continued stirring. Note the number of cc 

 of the alkali solution required to bring about this result. A 

 cream under most conditions should be churned at an acidity 

 somewhere between .55 and .70 per cent of acid, depending on 

 the richness of the cream and market requirements for flavor. 



Cream that requires 66 cc to neutralize it is not appre- 

 ciably riper than that requiring 64 cc. While in the case of 

 the Mann test, an error of 2 cc means a very appreciable varia- 

 tion in the ripeness of the cream. 



Since the amount of acid present in any given quantity of 

 cream depends on the amount of milk serum, we have adopted 

 the rule in our work of ripening cream to the point where it 

 requires .9 as many cc's of alkali as there are pounds of serum 

 in 100 pounds of cream, the milk serum being the portion of 

 cream not fat. For example, a cream testing 30 per cent fat 

 would have 70 pounds of serum. .9 of 70 would be 63; there- 

 fore in our practice a 30 per cent cream should be ripened to 

 require 63 cc of alkali or would contain .63 of one per cent of 

 acid. In the case of a 25 per cent cream, there would be 75 

 pounds of serum, .9 of which would be 67^. Therefore, that 

 cream would be ripened to .67 or .68 per cent acidity. Each 

 buttermaker can adopt for his own use whatever relation he finds 

 best. Then he can prepare a little chart and paste on the bottle : 



20 per cent cream requires .72 percent aciditv at churning. 



25 per cent cream requires .67 per cent acidity at churning. 



30 per cent cream requires .63 per cent acidity at churning. 



If the above is too high he may take .8 as much acidity as 

 he has milk serum. 



The advantages which we have found in the use of this 

 method are that the small bottles of normal solution do not lose 

 their strength as long as they are left properly corked. Several 



