194 MARKET DAIRYING 
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. 
