MANUFACTURE OF NEUFCHATEL. AND CREAM CHEESE. 13 
Various factors which may influence the keeping qualities of the 
cheese. Very little previous work has been done along this line. 
A study of each of the important steps has been found necessary 
to gather definite information with regard to the most efficient sys- 
tem of manufacturing, which includes a consideration of three fac- 
tors: (1) Initial condition of curd ; (2) rapidity of drainage ; (3) fat 
losses. The following subjects have been considered: 
1. Effect of different quantities of rennet. 
2. The use of pepsin as a substitute for rennet. 
3. Effect of temperature on the making process. 
4. Effect of starter on the making process: 
5. Effect of pasteurization and starters on the making process. 
6. Effect of pasteurization on the moisture content of the cheese. 
7. Effect of homogenization on the making process. 
EFFECT OF DIFFERENT QUANTITIES OF RENNET. 
A definite quantity of rennet is necessary in the manufacture of 
the Xeufchatel group of cheeses in order to obtain the characteristic 
curd, which must be neither too soft nor too brittle. The high cost 
of rennet requires that the curdling agent be used judiciously. So 
far nothing has been published regarding the most efficient and eco- 
nomical quantity of rennet to use for these cheeses. The quantity 
of rennet necessary depends not only upon the- rate at which the 
whey is expelled, but also upon the breaking up of the curd and 
upon the fat losses caused thereby. 
To determine this point, commercial liquid rennet in proportions 
varying from one-fourth of a cubic centimeter to 4 c. c. per 100 
pounds of milk was used, with the results shown in Table 1. In 
each case 250 c. c. of lactic starter was added to each 30-pound unit 
of milk. Thirty pounds of milk was used in each of the experiments. 
All the whey was collected and measured from the time the coagulum 
was poured upon the draining cloths until the curd was in fit condi- 
tion to ice, or in some cases for only part of that time. In any case 
the different parts of each sample were handled in the same manner. 
Fat determinations were made of each unit of a sample. 
It is noticeable that the losses of fat increase with the higher per- 
centages of fat in the milk, and there is also a slight increase in 
losses with the higher proportions of rennet. The losses of fat in the 
whey appear to be greatest when the large quantity of rennet causes 
the coagulum to be so brittle that it appears to break up more readily 
than when the lower proportion of rennet is used. Rennet in as 
small quantities as one-half of a cubic centimeter gave fairly satis- 
factory results with Neufchatel cheese, though the curd of cream 
cheese appeared somewhat too moist. When 3 or 4 c. c. of rennet per 
