DAIRYING 45 



1. The richness of the cream. 



2. The condition of the miik. 



3. The weather conditions. 



4. The number of bacteria present, whether added by a 



starter or from other sources. 



5. The temperature at which the cream is held. 



1. EFFECT OF RICHNESS OF CREAM ON RIPENING 



Some idea of the rate at which cream is ripening in the early 

 stages of the process may be gained by using the tests for acidity 

 which are employed for this purpose. Both Mann's acid test and 

 Farrington's Alkaline Tablets are capable of giving satisfactory 

 results. These tests do not necessarily measure the ripeness of 

 cream, but they may in the early stages of the process serve as a 

 guide to show how fast the acidity is progressing. Cream reaches 

 the limit of its acidity at a lower percentage of acid than milk. 



The fat in cream is neutral, and since the acidity must be de- 

 veloped entirely in the cream serum, the amount of serum present 

 will be governed by the percentage of fat in the cream. A cream 

 testing 20 per cent, fat contains 80 per cent, serum and one testing 

 50 per cent, fat contains only 50 per cent, serum. The amount of 

 acid that may be developed in the thinner cream will therefore be 

 considerably larger than it is possible to obtain in the richer cream. 

 The serum present may contain the same percentage of acidity in 

 both cases, but on account of there being so much more serum in 

 the thin than in the rich cream, the fat in the thin cream is mixed 

 with a larger quantity of the acid serum than is the 1 case with the 

 rich cream. This doubtless has ,some influence not only on the 

 rate at which cream ripens, but on the extent to which the butter 

 flavor is developed by the ripening. 



476. A simple calculation will show the serum acidity of 

 cream of any richness corresponding to a standard acidity for 

 cream containing a certain percentage of fat. If, for example, 0.6 

 per cent, acid in cream testing 25 per cent, fat may be accepted as 

 a standard, then the corresponding serum acidity of cream testing 



