PASTEURIZATION IN THE DAIRY. 169 



considerable amounts of cream are now subjected to pas- 

 teurization and subsequently shipped to a distant market. 

 In cheese-making the pasteurization has not yet been much 

 used, for the heat appears to produce changes which make 

 it difficult to procure a normal cheese from the milk. 



As a means of treating skim milk for the purpose of pro- 

 tecting from tuberculosis animals to whom it is fed, pasteur- 

 ization has come to be very widely used, and is becoming 

 more popular each year. Especially in the northern countries 

 of Europe where tuberculosis is very common, pasteuriza- 

 tion of milk in creameries is becoming almost universal. In 

 Denmark there is a law requiring this treatment for all 

 creamery skim milk that is to be returned to the farm to be 

 fed to live stock. Practically all creameries in Denmark, are, 

 therefore, supplied with pasteurizing apparatus, and the 

 pasteurization of the milk and cream is one of the everyday 

 routine parts of the work which is rarely omitted. In other 

 European countries, also, the process of pasteurization is 

 being rapidly adopted. In America the practice is by no 

 means so common, and, indeed, in the ordinary American 

 creameries pasteurization is rarely practiced. Our cream- 

 eries are not yet supplied with the necessary apparatus and 

 pasteurization would at present be hardly a possibility. It 

 seems probable, however, that the method of treating milk 

 and cream by pasteurization will before long become much 

 more widely extended in America. 



Although pasteurization does not produce great chemical 

 changes, it does have some slight effect upon milk. One of 

 its results is that the cream thus treated loses some of its 

 viscosity. Pasteurized cream is not so thick as ordinary 

 cream and does not whip so easily, a result which injures 

 its market value. The viscosity and whipping power can be 

 restored to the cream by a simple chemical device suggested 

 by Babcock and Russell (199). This they accomplish by a 

 material called viscogen which is prepared as follows: 2j^ 



