Preservation of Milk. 45 



The mud and manure that enters the milk is partially 

 soluble. Not over one-half of the manure can be re- 

 moved by a cloth strainer. The dissolving of the dirt 

 and manure allows most of the bacteria to pass into 

 the milk. Straining has practically no effect on the 

 keeping qualities of the milk. It is undoubtedly a 

 legitimate process, although from the standpoint of the 

 consumer in the city or in cheese-factory and creamery 

 much can be said against it, since it serves to make the 

 milk appear better than it really is and thus deceives 

 the consumer. The Swiss cheese makers do not allow 

 their patrons to strain the milk because they wish to 

 know its actual state of cleanliness. 



Cloth strainers may really be a source of contamina- 

 tion rather than an aid in the removal of bacteria, un- 

 less they are carefully washed and boiled at least once 

 a day, and placed where they will dry quickly and 

 thoroughly. The odor that is- sometimes noticable in the 

 dish-cloth or the kitchen towel is due to the fact that 

 in the moist cloth there is food enough to allow bacterial 

 growth to take place. In the same manner growth oc- 

 curs in the milk-strainer for it is almost impossible to 

 remove all traces of the milk by washing. This .growth 

 can be prevented and all trouble avoided by boiling the 

 cloth each day in order to sterilize it and by hanging it 

 where it will dry quickly. 



Filtering of milk. Filters composed of various ma- 

 terials as paper, cotton, and sand have been employed 

 for the filtering of milk. It was thought that by the 

 use of finer materials than cloth the bacteria would be 

 removed more efficiently. The use of these materials 

 has not been very successful. Unless well cleaned 

 after each period of use they soon become sources of 



