SKIM-MILK. 195 



this case we understand the same by the term "keeping 

 quality " as in case of new milk, for which reason all that 

 has been said in regard to the keeping quality of the latter 

 holds good also with sweet skim-milk. 



Different kinds of sweet skim-milk will keep for a 

 longer or shorter time according to the method of creaming 

 practised and the treatment it receives. The skim-milk 

 obtained from the Holstein method is often quite acid, 

 although it ought to be sweet. This skimmed milk being 

 often "blue-soured" and of poor quality, it cannot be 

 expected to keep long, and at farms where the method is 

 used the complaint is often made that the skim-milk 

 causes the calves to scour. In the Gussander method the 

 skim-milk is also reported not to keep well; in the deep 

 setting system, on the other hand, it keeps so much the 

 better. The skim-milk obtained by the ice method may 

 be even model as far as keeping quality goes i.e., if the 

 milk has been properly handled previous to the cream- 

 ing and later on has been treated in the dairy according to 

 the strict directions of the ice method. We have seen 

 that the skim-milk is not deprived of any of its bacteria in 

 the ice method; all germs present in the milk before the 

 cooling are found in it when they escape the torpor into 

 which they are placed through the cooling. By pasteuriz- 

 ing the skim-milk the number and vital power of the bac- 

 teria found in the same may be diminished, and if it is at 

 once properly cooled the advantages thus gained will be 

 retained. 



Separator Skim-milk. The skim-milk offering the best 

 guarantee for keeping quality is, however, that obtained by 

 the centrifugal method of creaming. Docent Fjord cor- 

 rectly stated in a lecture in 1883 that separated milk must 



