WHY CREAM TESTS VARY 121 



pretty conclusively that once more another definite 

 reason is found for variations in cream tests. When 

 the milk was separated at the correct temperature, 

 viz. 90 Fahr., a cream containing 42 % of butter 

 fat was obtained, but immediately the temperature 

 of the milk was allowed to fall to 80 Fahr. a 5 1 % 

 cream was produced. This to my mind, especially 

 during the winter months, would account for cream 

 tests becoming suddenly much higher on some days 

 than others, even though the speed of the machine 

 had been correct, and the regulating screw un- 

 changed. 



If a machine would do equally as good work 

 at low temperatures, I should prefer during the 

 summer months to separate at low rather than 

 higher temperatures, as the resulting cream would 

 keep better and arrive at the creamery in a sounder 

 condition ; but unfortunately we know from expe- 

 rience that separating milk which has been partially 

 cooled can only be accomplished at the expense of 

 clean skimming, owing to the more viscous con- 

 dition of the milk. This is more especially true 

 when the skimming operations occupy a consider- 

 able period of time. 



Summary of why Cream Tests Vary. 



1. Speed of machine being either too low or 



too high. 



2. Fluctuations in the temperature of the milk. 



