THE BUTTER OVERRUN 169 



Per Cent Butter Overrun. By per cent butter overrun 

 is understood the amount of butter made in excess of each 

 hundred pounds of butter fat used therefor. If 120 pounds of 

 butter are produced from 100 pounds of butter fat, the overrun is 

 20 per cent. Therefore if y stands for per cent overrun, b for 

 pounds of butter obtained from f pounds of butter fat then 



100 



Example: 1,800 pounds of cream containing 30 per cent of 

 butter fat produce 630 pounds of butter. Determine per cent 

 of butter overrun. 



Answer: 



630 -1, 800 Xy 3 ^ = i 



i,8ooXV& 



The above formula may also be written as follows: 



y = 100 -- i 



Thus the per cent of overrun from the foregoing example is de- 

 termined as follows: 



The Financial Value of the Overrun. The manufacturers 

 of butter consider that the overrun or even a part thereof is 

 sufficient to pay for manufacturing expenses and dividends on 

 the investment. It is therefore evident that the matter of 

 overrun is of vital importance to the creamery manager. He 

 knows the manufacturing cost per pound of butter, and if he 

 also knows the value of the overrun based on each pound of 

 butter manufactured, or on each pound of butter fat used in 

 manufacturing, then he will be fairly well informed as to the 

 extent of his profit or loss. The exact value of the overrun 

 per pound of butter or of butter fat, when the overrun and 

 the selling price of butter are known, is determined as follows: 



If y represents the value of overrun per pound of butter, 

 z the value of overrun per pound of butter fat, d the market 



