206 ILLINOIS STATF DAIRYMEN'S ASSOCIATION. 



Comparison of Butter Fat Churned and Recovered in the Butter. 



The results obtained from these comparisons gave such in- 

 teresting data in the 1907 experiments that it seemed best to col- 

 lect additional data of a similar nature. The 1908 experiment 

 offered an excellent opportunity for this work since it was con- 

 ducted on a much larger scale, thus reducing the percent of me- 

 chanical error and giving more uniform results. 



To obtain an accurate determination of the butter fat handl- 

 ed in each of the twenty comparisons, each delivery of milk and 

 cream was tested, involving a fat determination of 1494 indi- 

 vidual samples. The cream thus obtained for each churning day 

 was placed in two ripeners, a sample from which was tested in 

 triplicate, from each vat before and after the starter was added. 

 The cream in the ripeners was churned in four churnings from 

 which sixteen representative tubs were packed. 



Samples were taken for analysis from the churn and by trier 

 from the tubs twenty- four hours later. The percent of fat found 

 in these samples was in turn compared with the Babcock determi- 

 nation of fat delivered on that respective day. 



As an illustration. May 6, the amount of butter fat churned 

 according to each patron's test, was 819 pounds; the test of 

 cream in the two ripeners before starter was added gave 809.4 

 pounds and the test after starter was added gave 807.8 pounds. 

 All of this cream was churned in churnings Nos. i to 4. The 

 churns contained 297, 192, 297 and 195 pounds of butter res- 

 pectively, or a total of 981 pounds. Referring to Table 13, it 

 can be seen that the sample from churn i contained 80.81 per 

 cent of fat, and the average per cent of fat in the four tubs of 

 butter was 83.24. The same method of determination was used 

 in the other three churnings. The total pounds of butter fat 

 recovered for the day was, according to samples taken from 

 churns, 809.06 and from tubs 826.35. The same system of 

 checking was followed for each succeeding day 



