62 



THE BOOK OF CHEESE 



either as percentages of lactic acid or preferably as cubic 

 centimeters of normal alkali required to neutralize 100 

 or 1000 c.c. of milk. This kind of test is on the market 

 under different names> such as Mann's, Publow's, Far- 

 rington's and Marschall J s. 



82. Rennet tests. Several rennet tests have been 

 devised, but the one most widely used is the Marschall 

 (Fig. 10). This consists of a 1 c.c. pipette to measure 



the rennet extract, a small bottle in 

 which to dilute the extract, a special 

 cup to hold the milk and a spatula to 

 mix the milk with the rennet extract. 

 This cup has on 

 the inside from 

 top to bottom a 

 scale graduated 

 from at the top 

 to 10 at the bot- 

 tom. There is a 

 hole in the bottom 

 to allow the milk 

 to run out. 



83. Marschall rennet test. To make a Marschall 

 rennet test, 1 c.c. of rennet extract is measured, with 

 the 1 c.c. pipette, and placed in the bottle. Care 

 should be exercised to rinse out the pipette. The bottle 

 is then filled to the mark with cold water. After the 

 milk has been heated to the setting temperature, 84- 

 86 F., the cup is filled with milk and set on the edge of 

 the vat so that the milk running out through the hole 

 in the bottom of the cup will flow into the vat. Just 

 as the surface of the milk reaches the mark on the cup, 

 the diluted rennet extract is added and thoroughly mixed 



i , 



FIG. 10. Marsc 



all rennet test. 



