Testing the Purity of Milk. 



139 



quickly added to the warm milk and the time 

 rfequired for coagulation 

 noted. 1 Milk sufficiently ripe 

 for cheddar cheese making 

 will coagulate in 30 to 60 

 seconds, according to the 

 strength of the rennet ex- 

 tract used. 



158. The Marschall ren- 

 net test is used for the same 

 purpose as the Monrad test. 

 The directions for this test 

 are as follows : Fill the small 

 glass with pure water to 

 the mark, pour into it one 

 cc. of rennet extract and 

 rinse the pipette in the same 



FIG. 48. The Monrad rennet test. water< Fm ^ cup ^^ 



milk to the zero mark, add the rennet, mix thoroughly 

 and allow it to stand. The sweeter the milk is, the 

 longer it will take to 

 coagulate, and the more 

 milk will run out of the 

 cup before the point of 

 coagulation is reached, 

 when the flow of milk 

 will cease. The time re- 

 quired for coagulating tj 

 the milk is shown di- ^ 



rectly by a Scale On the FIG - 49 - Tne Marsphall rennet test. 



inside wall of the cup (see fig. 49). 



1 Decker, Cheese Making, 1900, p. 36. 



