300 ILLINOIS STATE DAIRYMEN'S ASSOCIATION 



w!iatsoever and, while sweet cream can be made into fine butter 



without pasteurization, there can be no doubt that the keeping 



quahty of butter is improved thereby. Pasteurization will also 



greatly aid in making a uniform product from day to day and, 



considering the importance of uniformity, this alone should be 



sufficient inducement to creameries to pasteurize, even though all 



the cream is sweet when received. 



Sour Cream. 



Experiments in pasteurization indicate that more germs are 

 killed in sour cream than in sweet. This is due to the fact that 

 heat plus acid is more fatal to organisms than is heat without 

 acid. 



If all the cream is sour when received, it can be pasteur- 

 ized without difficulty providing it contains a liberal percentage 

 of fat and is well mixed before heat is applied. All cream should 

 be strained through a fine mesh wire strainer when received, as 

 this will help to break up the cream and remove any free casein. 

 Thin and lump}^ cream is sure to give trouble when pasteuriz- 

 ing, and these conditions must be overcome in order to obtain 

 satisfactory results from pasteurization. Quite a number of 

 creameries have been in the habit of pasteurizing in winter and 

 discontinuing it at the approach of warm weather, evidently 

 because buttermakers believe that sour cream was difficult to 

 pasteurize. The fact of the matter is, however, that there is 

 ordinarily less trouble pasteurizing in summer than in winter, 

 as the cream is more uniformly sour in hot w^eather than during 

 the colder season. 



If reasonably sweet cream is received during the winter 

 months there will, of course, be little trouble in pasteurizing it, 

 but with the approach of spring and warmer weather, some 

 sour cream will be coming in, and that is when troubles in pas- 

 teurizing are most pronounced. 



Sweet and Sour Cream. 



Mixed sweet and sour cream is the cause of most of the 

 difficulties encountered by buttermakers in pasteurizing cream 

 for buttermaking. As has already been stated, it is possible to 



