Sept., 1909.] 



A STUDY OP FARM BUTTER-MAKING. 



277 



butter fat from the amount of butter made (1 1.25-1 0.7 5=z0.5). 

 .5 of a pound represents the gain in weight in the finished butter 

 on 10.75 pounds of fat determined from a Babcoek test of cream. 

 On 100 pounds of fat, or expressed in percentage the overrun 

 would be (.5^10.75) 100=4.7%. 



In estimating butter from butterfat it is generally figured 

 that one pound of fat represents 1 1-6 pounds of butter, or an 

 overrun of 16.4%. It will be noticed from the table that in 

 actual practice only four out of ten obtained this amount even 

 when the losses in skimming were not considered. 



It is impossible to draw accurate conclusions as to the low 

 yield of butter from a summary of the above records as each 

 churning is made under widely different conditions. In study- 

 ing the table, each churning should therefore be studied sepa- 

 rately rather than drawing conclusions from average results. 



The amount of butter which is obtained from a given quantity 

 of butterfat in milk depends upon (1) the losses of fat in skim 

 and buttermilk, (2) losses in milk, cream and butter in handling, 

 and (3) the composition of the butter. 



LOSSES OF FAT IN BUTTERMILK. 



One factor which stands out prominently, considering the ten 

 churn ings, is the relation between the churning temperature, the 

 length of time it takes, and the loss in the butter-milk as shown 

 by the following table. 



TABLE III. — Shoichu) relation hetvjeen dm rninrf temperature, time of 

 churning, and loss of fat in the buttermilk. 



No. of churning. 



No. of churning. 



o 



*^ 



■4-» 



3 



a . 



Sa 



1 



3 



4 



7 



10 



Av. of 5 Churning 



60° 



59 



62 



62 



74 



63.4 



2 



5 



6 



8 



9 



Av. of 5 Churning. 



.08 

 .06 

 .05 

 .05 

 1. 

 .248 



