40 CHEESE MAKING. 
The rennet is first measured with the 5c. ¢. pipette (Fig. 20). 
The rennet can very easily be measured by this instrument, and 
the tube being narrow makes the measurement accurate. The 
rennet in the pipette is delivered into the 50 ec. ¢. flask, and 
what little rennet adheres to the inside of the pipette is rinsed 
into the flask with some water. The flask is then filled with water 
to the 50 ¢. ec. mark on the neck, and the solution mixed ty 
shaking. The temperature of the milk should be 86° F. It is 
measured in the tin cylinder, emptied into the half-pint basin, 
and 5 ¢. e. of the dilute extract is measured into the 160 ¢. c. of 
milk. The number of seconds required to curdle the milk is then 
noted. Ifa few specks of charcoal are scattered on the milk 
and the milk started into rotary motion in the dish with a ther- 
mometer, the instant of curdling can be noted by the stopping 
of the specks. They will stop so suddenly as to seem to start back 
in the opposite direction. 
83. Use Thermometer to Stir Milk. 
By using a thermometer, the temperature can be constantly 
watched; and if the temperature should fall, it can quickly be 
brought back to 86° F. by setting the basin in a pail of warm 
water for a few seconds. 
84. The Marschall Rennet Test. 
Another ingenious form of rennet test which is used in 
many factories is the Marschall test, as it keeps its own time. It 
consists of an ounce bottle with a mark on it to indicate 20 ¢. ¢.; 
and a spatula for stirring the milk; a 1 ¢. ¢. pipette is used for 
measuring rennet into the bottle in which it is diluted up to the 
mark on the bottle; a test basin, which is a vessel of a little over 
a pint capacity, on the inner surface of which is a scale begin- 
ning with 0 at the top and numbering by half divisions to 10 near 
the bottom of the vessel. A hole in the bottom of the vessel is 
fitted with a cork in which is inserted a tube of a very fine bore. 
(See Fig. 21.) 
85. How to Use the Test. 
To make a test the vessel is filled with milk at the desired 
temperature, and when the milk has drained through the little 
tube until the top is at the 0 mark, the diluted rennet is 
