48 DAIRYING 



Per Cent. Fat in the Skim Milk. 

 Spring. Fall. 



.11 Stable Feed 14 



.13 Mixed Feed 16 



.15 Pasture Feed 18 



308. The stable milk skimmed a trifle better in each case 

 than the pasture milk. Whether this is due to the difference in 

 viscosity or the effect of exercise of the cows is uncertain, but 

 it has been noticed that morning milk skims better than night 

 milk, and milk that has stood quietly better than that which has 

 been transported. 



The effect of such differences in the skim milk may not seem 

 to amount to much, but .1 pound buter fat is worth 2^ cents, 

 and this loss may easily occur in each 100 pounds milk skimmed, 

 if all the known precautions for skimming clean are not taken. 



Methods of Heating Milk Before Skimming. 



309. Holding milk at a skimming temperature (85 de- 

 grees F.) for one-half hour or more before skimming is not ad- 

 visable because of the rapid development of bacteria at this tem- 

 perature, and a partial ripening of the milk which may be re- 

 sponsible for objectionable flavors in the cream or the butter if 

 the latter is made from the cream. 



This makes the heating of milk in a large receiving vat at a 

 creamery objectionable because it may be thus heated for too long 



a time. 



310. Heating milk by forcing steam directly into it is also 

 objectionable, first, because of the unevenness of the heating; 

 second, because the excessive heat from the steam may coagulate 

 particles of casein around the fat globules, and third, the steam 

 may contain impurities from the water, or the boiler from which 

 it comes. 



Milk heaters with a revolving dasher that throws the milk in 

 a thin film around a steam heated drum are not the best kind of 

 a heater because the excessive agitation splits up the fat globules, 



