DAIRY HUSBANDRY 
71 
EXERCISE NO. 54 
Object: To become acquainted with the Marschall rennet test. 
Procedure: The rennet test is used by cheesemakers to determine the 
ripeness of the milk. It is claimed that rennet tests are more 
sensitive to acidity during the early phases of acid develop¬ 
ment than the acid tests, and hence are to be preferred by 
cheese makers. 
A. Fill the small glass with pure water to the mark and pour into 
it 1 cc. of rennet extract. Rinse the pipette with the same 
water. 
B. Fill the cup with milk to the zero mark, add rennet, mix 
thoroughly and allow to stand. 
C. Milk will flow from the cup until coagulated. The scale on 
the inside of the cup shows directly the time necessary for coag¬ 
ulation. The sweeter the milk, the more will flow from the 
cup. 
Note: For cheese making the correct degree of acidity is 
from 0.19-0.21%, or when the milk coagulates at 2^ spaces 
Marschall rennet test, and rennet should be added at that 
time. 
Observations: 
Conclusions: 
Questions: (1) Describe the Monrad rennet test. 
(2) What is rennet extract, and how is it obtained? 
(3) Why is it important that milk develop the proper degree of 
acid when making cheese? 
(4) What is the object of adding rennet extract to milk when 
making cheese? 
References: F. & W. 157, 158; Jud. pp. 238-241; St. pp. 304-306. 
