40 



lecturer can direct and supervise the work closely and gradually leave 

 the students a tjreater de«:ree of indej)endence as they show a proper 

 comprehension and power of manipulation.] 



9. Use of pepsin in place of rennet in cheese making. — (Reference 

 No. 8, p. 53.) Rennet extracts are practically impure and dilute 

 forms of pepsin. In place of rennet extract one can use ])epsin at the 

 rate of 5 ^rams for 1,000 pounds of milk. The pepsin is dissolved in 

 any convenient amount of water before addition to milk. Only scale 

 pepsin should be used. The pepsin solution should be made up daily 

 in just the amount needed for the day. 



EXPERIMENT AND PRACTICE WORK, SEVENTH LECTURE. 



Time required. — Two hours or more can be easily given to the work 

 outlined below. 



Apparatus, etc., required. — (1) Pails, arrangements for heating, 

 small vats, thermometers; (2) rennet extract, pepsin; (3) skim milk, 

 10 to 20 pounds or more for each worker; (4) whole milk, 100 pounds 

 or more, and (5) rennet test and acid test. 



1. Preparation of starter. — Prepare starter according to directions 

 given. 



2. Ripen 10 or 20 pounds of milk in a pail with, and without using 

 a starter. Apply rennet test and also determine degree of acidity. 



After the milk has ripened properly add rennet. 



Compare pepsin and rennet. 



When some familiarity has been acquired in handling small amounts 

 of milk, then perform the work with 100 pounds or more of skim milk 

 and later with whole milk. 



EIGHTH LECTURE. 



CUTTING AND HEATING CURD. 



1. Purpose of cutting curd. — The object of cutting curd is to allow 

 the whey to go out of the paracasein. This is more rapid and com- 

 plete in proportion as the pieces of curd are smaller (reference No. 3, 

 p. 71). 



2. WTien to cut curd. — Curd cut too soft results in large losses of fat 

 and smaller yield of cheese. Curd that is too hard before cutting 

 loses whey less easily and results in poor quality of cheese. Henc(^ 

 curd must be cut at right stage of hardness. The stage for cutting 

 is ascertained in this way: The end of index finger is inserted obHquely 

 into curd half an inch or more and then slowly raised to surface. If 

 the curd breaks apart with a clean fracture without leaving small bits 

 of curd on the fmger and if the whey in the broken surface is clear 

 and not milky, the curd is ready to cut (references No. 3, p. 72, and 

 No. 8, p. 53). 



