204 CREAMERY BUTTER MAKING 



GERBER FERMENTATION TEST. 



This test is simpler than the Wisconsin Curd Test and 

 can be used for both milk and cream. Where milk need 

 not be examined specially for gas-producing organisms, 

 this test will give as satisfactory results as the curd test. 

 The essential difference between the two tests is the elim- 

 ination of rennet extract with the Gerber. 



Making the Test; The samples of milk or cream are 

 placed in glass tubes which are numbered to correspond 

 with the names of the patrons. These tubes are warmed 

 in a tin tank containing water whose temperature is main- 

 tained at 104 F. throughout the test by placing a lamp 

 under the tank. At the end of about six hours the samples 

 are examined for flavor, color, taste and consistency. After 

 this examination, they are put back into the tank to be re- 

 examined after another interval of about six hours. Any 

 "off" condition of the milk or cream can usually be told at 

 the end of six to twelve hours. 



