CHAPTER IV. 



HEATING THE MILK 



PREPARING THE MILK FOR SEPARATION. 



On the farm the milk is in its very best condition for separa- 

 tion immediately after milking, and the warm skim milk is then 

 at its best for feeding purposes. Indeed, where convenient and 

 where the separator is not too far from the stable it may be started 

 as soon as the milkers are far enough ahead to keep it going and 

 the milk may thus be strained directly into the separator tank, and 

 thus save the cleaning of an extra vessel. But the separation 

 should never be done in the stable or anywhere where smells and 

 dust may contaminate the cream. If, by some accident, the supply 

 of milk should not be kept up, a little water or skim milk should be 

 run through the separator to drive out the cream. If the night's 

 milk is not separated till morning it should be warmed to 80 or 90 

 degrees. This is essential with all hollow bowl separators, and 

 only in a less degree with the others. 



At the creameries the heating of the milk is an important 

 function and is but seldom done in a satisfactory, uniform man- 

 ner. The two principal systems used are, either heating the milk 

 in a large body in the receiving vat, or passing it through some 

 heating apparatus on its way from there to the separator. The 

 danger of the first lies in the keeping of the already old milk 

 at a high temperature and thus souring and developing bad flavors, 

 and of the second, in the fact that the fat does not take the heat as 

 quickly as the "serum" and thus the true temperature desired is 

 not obtained, and also in the fact that no automatic regulator has 

 been employed that would keep the milk from varying consider- 

 ably. I have thus, even in good creameries, observed a variation 



of 10 deg. with heaters like Fig. 27. 



< 



THE HEATERS. 



Most of the heaters used in our American creameries were 

 similar to Fig. 27, which represents an improvement on the so- 

 called "Danish Weston" heaters, but unless they are made 



37 



