TESTS USED IN CHEESE-MAKING 435 



trouble. It is also desirable to get an idea of the 

 amount of suspended dirt in milk, as this may often 

 be an indication of the general bacterial condition of 

 the milk, since bacteria generally keep company with 

 dirt. We have tests for accomplishing these objects. 



TEST FOR DIRT IN MILK 



The following is a quick, simple, practicable method 

 for indicating in a rough way how much suspended 

 dirt milk contains : Provide several granite-iron fun- 

 nels 2^ or 3 inches in diameter. Place in these some 

 clean absorbent cotton, making the upper surface as 

 smooth and flat as practicable and somewhat compact. 

 Have these near the weighing-can so that one can be 

 attached on inside of can. When milk is dumped in 

 can and thoroughly mixed, take a pint and pour on 

 cotton in funnel. Any suspended dirt quickly shows. 

 The method might be improved by laying a circular 

 piece of white muslin on top of the cotton. The test 

 performed under the eyes of a patron would be con- 

 vincing. Milk should contain no visible dirt in sus- 

 pension. 



THE FERMENTATION OR WISCONSIN 



CURD-TEST 



Milk frequently contains objectionable forms of 

 organisms or ferments that are not made perceptible 

 by ordinary methods of observation. The condition 

 arises particularly in milk used for cheese-making and 

 may result in serious injury to the quality of the 

 cheese. The Wisconsin experiment station (Wisconsin 

 experiment station 12th and 15th annual reports, 

 1895 and 1898) has applied certain principles to the 



