DETECTION OF TAINTS 191 
WISCONSIN CURD TEST. 
This test originated at the Wisconsin Dairy School. 
The name of the test implies that the samples of milk 
to be tested are curded, which is accomplished in a man- 
ner similar to that in which milk is curded for cheese 
making. 
The Wisconsin Curd Test is frequently spoken o1 as 
“fermentation test,” since the process involved consists in 
fermenting the milk by holding it at a temperature at 
which the bacterial fermentations go on most rapidly. 
Apparatus. This consists of one pint cylindrical tin 
cans placed in a tin frame, and of a well insulated box 
made so that the tin frame will nicely slide into it. Added 
to this is a case knife, and a small pipette used to measure 
rennet extract. 
The construction of the box and the position of the cans 
inside is illustrated in Fig. 49. This box consists of 
three-eighths inch lumber, the inside of which is lined with 
a quarter inch thickness of felt. Narrow strips are tacked 
on the felt and tin upon these, the object of the strips 
being to prevent conduction of heat by contact of the tin 
with the felt. The cover of the box is constructed in the 
same way and made to fit tight. This construction makes 
it possible to maintain a nearly constant temperature of 
the samples which are surrounded by water as shown in 
the illustration. 
Making the Test. A curd or fermentation test is made 
at the creamery by selecting from each patron about two- 
thirds of a pint of milk and placing this in the tin pint 
cans after they have been thoroughly sterilized. Each 
pint can should be provided with a sterilized cover which 
is placed upon it as soon as the sample has been taken. 
