12 DAIRYING 



Second, more cream will rise in twenty-four hours than in 

 twelve hours. The difference between the weight or the specific 

 gravity of the butter fat and the milk serum is not very great and 

 the cream is therefore slow in rising to the surface. It will con- 

 tinue to rise so long as the milk is perfectly sweet, but it is 

 stopped by the souring and thickening of the milk. 



Third, the milk of a '"fresh" cow contains fat globules of a 

 larger size than those in the milk of a "stripper/' and the cream 

 will therefore rise more quickly at the beginning than at the end 

 of the cow's period of lactation. This gradual diminution in size 

 of the fat globules, together with the increase in viscosity of the 

 milk from the beginning to the end of the lactation period, has a 

 tendency to retard the cream separation by any process. 



Fourth, the fat globules of milk are not uniform in size with 

 all breeds of cows ; the average size of these globules is to a cer- 

 tain extent a breed characteristic. The Holstein and the Ayrshire 

 cows, as a rule, give milk which contains smaller fat globules 

 than those in the milk of the Jersey and Guernsey breeds. On 

 this account cream will separate more quickly and completely 

 from the milk of some cows than from that of others ; the larger 

 the fat globules the more quickly the cream will rise and the 

 richer it will be when all other conditions are uniform. 



Fifth, cream is ordinarily skimmed from shallow pans with a 

 skimmer, made clam-shell shape and about six inches in width. 

 Several small holes are punched in the center of its bowl to allow 

 the skim milk to drain away from the cream while skimming. If 

 this skimmer is skillfully used, the cream is nearly all taken from 

 the milk, but a careless handling mixes the cream more or less 

 with the skim milk, and fails to get all the cream. 



2. Characteristics of "Shallow Setting" Cream. 



232. The "shallow setting" method is a rather crude one, but 

 it has been used for many years, and is still found in some local- 

 ities. Earthenware crocks of varied sizes are occasionally substi- 

 tuted for the tin pans, but the process of getting the cream differs 

 only in the shape and material of the containing vessel. 



