THE PASTEURIZATION OF MILK 



surrounding the handling of the milk were noted 

 in order to determine if other factors aside from 

 the temperature and holding time had any effect 

 upon the cream line. 



In making the tests, the samples of milk taken 

 were set in standard cream gauge glasses and the 

 actual percentage of cream showing upon the milk 

 as indicated thereon was carefully noted. These 

 tests were made during the early part of Decem- 

 ber, 1914. 



FIRST TEST. The first test was made at a plant 

 in which the pasteurizing apparatus consisted of 

 three tanks of the type shown in Fig. 13. Each 

 tank had a capacity of about forty cans of milk, 

 and after being filled the milk was heated by 

 means of a revolving coil of pipe extending through 

 the tank, through which coil hot water and steam 

 were forced. After the milk reached the proper 

 temperature, the steam was shut off in this coil 

 and the milk was held at the same temperature 

 for the desired length of time. It was then dis- 

 charged into a cooler consisting of a tank in which 

 were revolving disks, which is not here illustrated, 

 and immediately cooled. Since it required con- 

 siderable time for the tank to be fully emptied 

 212 



