WORKING OF CENTRIFUGAL MACHINES IN DAIRIES. 



149 



Skim-milk, containing only '25 per cent of fat, is not, as a rule, 

 adapted for making into skim-milk cheese. Nothing is easier, 

 where there is a demand for skim-milk cheese, than to so regulate 

 creaming that a skim-milk is obtained with the desired higher 

 percentage of fat. Skim-milk, when Pasteurized, no longer possesses 

 the property of yielding a coherent coagulation under the action of 

 rennet. 



There can hardly be any dairies 

 in which throughout the whole year 

 there will be a supply of such cold 

 water at command that the requisite 

 quantity can be safely enough pro- 

 vided. For that reason ice cannot be 

 dispensed with in dairies, and the 

 necessary supply must be provided. 



Fig. 46. Laval Cream-cooler. 



The precaution of cooling the cream 

 quickly and thoroughly is one which is 

 apt to be least recognized in practice, 

 although it is known by thousands of 

 observations that cream at warm tem- 

 peratures quickly loses its pure taste. It 

 is only by a happy chance that cream, 

 which has been kept for some time at a 

 high temperature, yields good butter. 



If creaming be effected at 30 C., it 



will be sufficiently near the necessary quantity to give, for every litre of 

 milk which passes through the drum, "2 to -3 kilograms of ice. 



76. The Proper Working of Centrifugal Machines in Dairies. 

 Success in dairy management requires that there should be no failure 

 to provide sufficient and well-arranged rooms, and that the staff on 

 the one hand are not overworked, and, on the other hand, that they 

 observe the greatest care and punctuality. 



In every good and well-regulated dairy, separators are used, and in 

 those in which cheese is not made there should be at least ten rooms. First, 

 a room for the milk samples; second, for cleaning the vessels and utensils; 

 third, for separators and their necessary gear; fourth, for keeping milk, 

 skim-milk, and cream, with an arrangement for cooling; fifth, for butter- 

 casks; sixth, for cream-souring and the working of butter; seventh, for the 

 storage of ice; eighth, for coal storage; ninth, for steam-engines; and tenth, 



