194 



Testing Milk and its Products. 



butter maker's skill is shown by his ability to reduce the 

 losses by waste in handling the milk, cream and butter, 

 as well as the losses of butter fat in skim milk and butter 

 milk, and his carefulness in weighing, sampling and 

 testing the milk, cream and butter made. 



217. Overrun from cream. The overrun from cream 

 is, as already stated, larger than from milk because 

 there is no loss of fat in the skim milk to be consid- 

 ered. Rich cream will give a slightly larger over- 

 run than thin cream, for the same reasons as have been 

 shown in the calculations of overrun from milk of dif- 

 ferent fat contents. If similar calculations are made 

 for cream of different richness as those given above for 

 milk, the fat available for butter-making and the yield 

 of butter per 100 pounds of fat in the cream will be 

 as shown below. A mechanical loss in the process 

 of butter-making amounting to 2 per cent, has been 

 assumed in these calculations : 



We note that the overrun for cream of different qual- 

 ity under the conditions given ranges from 16.6 for 20- 

 per cent, cream to 17.6 for 40-per cent, cream. A some- 

 what larger overrun would be obtained when the butter 

 made contains less fat and more water than assumed. 



If no losses from waste are considered in the account, 

 the figures for fat available for butter will be 98.8, 99.3, 



