168 Milk and Its Products. 
is to add a spoonful of rennet of known strength 
to a teacupful of milk and, after stirring the two 
together thoroughly, to note carefully the time re- 
quired for coagulation. Another and more exact 
method, known as the Monrad test, is made as fol- 
lows: To a measured quantity of milk at a given 
temperature a measured quantity of rennet of known 
strength is added; ordinarily the commercial rennet is 
diluted nine-tenths for this purpose. The rennet is 
thoroughly stirred with the milk, and the time re- 
quired for coagulation is carefully noted. This is 
simply a development of the cup test, and is better 
because of its greater delicacy and accuracy; the 
milk and rennet being more carefully measured, and, 
diluted rennet being used, a wider range of delicacy 
is reached. Still 
another form of ren- 
net test, known as 
the Marschall test, 
has been devised. 
In this test the milk 
is measured into a 
vessel, one of whose 
sides is graduated 
and in the bottom 
of which there is a 
minute orifice. The 
rennet is added to 
the milk, and the 
vessel so placed that the milk can escape from the 
hole in the bottom. So long as the milk remains 
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Fig. 24. Marschall rennet test. 
