264 MODERN BUTTER MAKING. 



result will be the number of pounds of milk testing 

 the desired per cent. The difference between this 

 result and the original amount of milk will be the 

 quantity of skim-milk to be extracted. 



Problem: 2,000 lbs. of milk testing 3.5 per cent of 

 butter fat is to be made to test 4 per cent. How 

 many pounds of skim-milk must be extracted? 



Solution: 



3.5-=-4=.875. 



2,000X-875=1,750 lbs. of milk testing 4%. 



2,000—1,750=250 lbs. of skimmilk to be extracted. 



(b) When skim-milk is used to lower fat in milk. 



When reducing the fat content in milk by adding 

 skim-milk, the following rule may be used : 



Rule: Multiply the milk by its per cent of butter 

 fat, divide the product by the desired per cent of 

 butter fat, multiply the quotient by 100 and the pro- 

 duct will be the total amount of milk with the de- 

 sired test. The difference between the original 

 quantity and the total quantity will give the number 

 of pounds of skim-milk to be added to produce the 

 desired per cent of butter fat. 



Problem: 5,000 lbs. of milk testing 4.5 per cent 

 is to be reduced to 3.8 per cent butter fat. Plow 

 many pounds of skim-milk must be added to reduce 

 the test to 3.8 per cent of butter fat? 



Solution: 



5,000 X4-5==225 lbs. fat in milk. 



225-=-3.8=59.21. 



59.21X100=5,921. 



5,921—5,000—921 lbs. of skim-milk to be added to 

 5,000 lbs. of 4.5% milk to reduce the test to 3.8%. 



