186 AMERICAN DAIRYING. 



patented. This does very efficient work; it 

 will cool a vat of cream from 70 cleg, down to 

 within 3 cleg, of the temperature of the water 

 used in a short time, a full vat requiring not to 

 exceed thirty-five minutes. Care must be used 

 here, as this rapid cooling of the cream does 

 not harden the fat with the same degree of 

 rapidity that the thermometer indicates it has 

 cooled the cream. It is best to cool a few 

 degrees cooler than you wish to churn, or con- 

 tinue the cooling operation for a time to give 

 the fa-t in the cream time to harden. 



Temperature to churn. The temperature 

 to churn is the next question. The old practice 

 was 58 to 62 cleg. This is the temperature at 

 which a large majority churn to-day. I have 

 been studying over this churning question for 

 several years. My early work was in the line 

 of acidity, which work was clone in connection 

 with the Illinois Experiment Station and a 

 bulletin issued which covered our work. But 

 when the Babcock test was introduced I com- 

 menced to use it on the buttermilk and secured 

 results that surprised me very much. The va- 

 riations in the percentage of fat were astonish- 

 ing, the range being from .1 of 1 per cent up 

 to 2 per cent (two per cent). At the end of the 

 first year I had learned that the churning was 

 much more exhaustive in winter than it was in 

 summer. I had supposed the opposite would be 



