72 CANADIAN DAIRYING. 



fat) the cream in a given time, but the greater will be 

 the volume. The longer the time the cream remains 

 on the milk, after the first twelve hours, the less the 

 volume of cream, but it will be richer, t.e. t contain 

 more fat. The shrinkage in volume of cream on a 

 can of milk 8j^-inches in diameter and 20 inches 

 deep, is about one-eighth of an inch for each twelve 

 hours, after the first twelve hours, up to forty-eight 

 hours after setting. 



It is very important to cool the milk as rapidly as 

 possible to a temperature below 45 degrees, as this 

 retards the souring of the milk and so hinders cream 

 rising. According to Babcock, it also tends to pre- 

 vent the formation of lacto-fibrin, which hinders the 

 cream rising. Experiments conducted at the Ontario 

 Agricultural College gave results as follows : Cans of 

 milk cooled to an average temperature of 41 degrees 

 contained .2 per cent, fat in the skim-milk. Similar 

 cans cooled to 47 degrees gave a loss of .3 per cent, 

 fat in the skim-milk ; while lots of the same milk 

 cooled to 52 degrees contained .7 per cent, fat, or 

 over three-quarters of a pound of butter in one 

 hundred pounds of skim-milk. These results show 

 very forcibly the need of cooling to below 45 degrees 

 in order to recover most of the fat or cream. 



While experiments indicate a slightly greater loss 

 of fat in the skim-milk by delaying the setting of 

 milk from one-half to one hour after milking, the 

 difference is not sufficient to cause any anxiety in 

 case the setting is delayed a short time through 

 pressure of other work. The rule is set at once if 

 possible. 



