212 ILLINOIS STATE DAIRYMEN'S ASSOCIATION. 



The above Table offers a striking comparison of the over- 

 run obtained. The average over-run when based upon butter 

 fat churned was 20.5 per cent. The highest over-run for a 

 single churning, No. 41, was 26.7 per cent and lowest, in churn" 

 ing 20, which was 15.3 per cent. In these same two churnings 

 the composition in the butter packed in the tubs permitted an 

 over-run of 24.3 and 17.2 per cent respectively. The Table 

 shows remarkable uniformity between butter fat churned and 

 butter fat recovered. The only mechanical loss considered for 

 each individual churning was the butter fat lost in the buttermilk. 

 If the creamery operators are to use the over-run recorded in the 

 above Table as standard, they must take the following facts into 

 consideration : 



1. The loss in handling the milk and cream until it reaches 

 the churn, must be reduced to a minimum. 



2. The weight of butter packed must be the same as weight 

 on bill of sale. 



3. The butter fat paid for must be approximately the actual 

 amount received. 



4. After allowing for the mechanical loss, the over-run 

 should be consistent with the per cent of fat actually in the 

 butter. By referring to Table 15, May 26, the butter in the tubs 

 from churning 25 contained 81.47 per cent fat and churning 26 

 from the same vat of cream contained 85.00 per cent of fat or a 

 difference in fat content of 3.53 per cent. 



The greatest factor influencing over-run obtained in cream- 

 ery operation, is the sampling and testing of the milk and cream 

 received. An error of one-tenth of one per cent in testing 4.0 

 per cent milk and one per cent in 40 per cent cream will alter the 

 over-run 3 per cent. 



Table 17 is made up from Tables 15 and 16, in order to give 

 a complete daily comparison of the butter fat received and 

 churned, total pounds of butter made, together with the respect- 

 ive over-run. 



