ON BUTTERMAKING 7 



pies of suspected milk from each patron are placed 

 in small glass jars holding about half a pint. The 

 milk is heated to 90 F. and retained at this tem- 

 perature to make conditions favorable for the 

 growth of any abnormal bacteria or ferments that 

 may be present. Cheesemakers add a small amount 

 of rennet to the samples of milk so that a curd is 

 formed that may be studied for defects: The 

 samples are examined frequently during the day, 

 and tested for odors or other defects that may have 

 developed. 



What are the uses of the fermentation test? 



1. To assist in locating sources of bad flavors 

 in milk, cream, and butter. 



2. To study the nature of the milk furnished by 

 each patron. 



3. To study the action of suspected starters on 

 samples of milk. 



How should milk and cream be sampled for fat 

 testing? 



Samples of milk can be accurately measured by 

 the use of a 17.6 c. c. pipette. They can also be 

 weighed, using 18 grams for each test. 



All samples of cream should be accurately 

 weighed on reliable scales, using 4 grams for each 

 sample. Accurate work cannot be done by using 

 a pipette for measuring, as cream of different per- 

 centages of fat varies considerably in volume. 



When milk and cream are paid for on the fat 

 basis, composite samples of each patron's milk or 

 cream are kept and tested at least twice each 

 month 



