16 
BULLETIN 669, U. S. DEPARTMENT OF AGRICULTURE. 
PEPSIN AS A SUBSTITUTE FOR RENNET. 
The scarcity of rennet has caused cheese manufacturers to look for 
a substitute. Table 2 shows the results of pepsin tests with cream 
cheese in quantities of one-sixth to one-twenty-fourth of a gram per 
100 pounds of milk and fat determinations made of the whey. 
Table 2. — Effect of varying quantities of pepsin upon fat loss and condition of 
curd for cream cheese. 
Sam- 
ple 
No. 
Quantity of curdling agent per 
100 pounds of milk. 
Fat loss 
Fat in 
in whey. 
milk. 
Per cent. 
Per cent. 
0.18 
5.8 
.14 
5.8 
.14 
5.8 
.15 
5.8 
.14 
5.8 
.14 
5.8 
.08 
5.9 
.10 
5.9 
.08 
5.9 
.10 
5.9 
.08 
5.9 
Setting 
temperature. 
Starter per 
unit of 30 
pounds. 
Criticism 
of curd. 
Pepsin, 1/6 gram . 
Pepsin, 1/8 gram . 
Pepsin, 1/12 gram 
Pepsin, 1/16 gram 
Pepsin, 1/24 gram 
Rennet, 1 c. c 
Pepsin, 1/6 gram. 
Pepsin, 1/8 gram . 
Pepsin, 1/12 gram 
Pepsin, 1/24 gram 
Rennet, 1 c. c 
27° C. (80.6° F.) 
do 
do 
do 
do 
do 
29° C. (84.2° F.) 
do 
do 
do 
do 
200 c. c. 
...do... 
...do... 
...do... 
...do... 
...do... 
250 c. c 
...do 
...do 
...do 
...do 
Too dry. 
Good. 
Do. 
Do. 
Too moist. 
Good. 
Too dry. 
Good. 
Do. 
Too moist. 
Good. 
Pepsin used at the rate of about one-twelfth of a gram per 100 
pounds gave the best results. With one-sixth of a gram for an equal 
quantity of milk the curd was too dry, while it was too moist when 
only one-twenty-fourth of a gram was used. The fat losses in the 
whey were practically the same for both the pepsin-made and the 
rennet-made cheese. 
EFFECT OF TEMPERATURE ON THE MAKING PROCESS. 
The literature about Neufchatel and cream cheese shows different 
opinions relative to the temperature to use in their manufacture, the 
figures varying from 20° to 25° C. (68° to 77° F.). In our experi- 
ments to test this matter somewhat higher temperatures were found 
preferable. Temperatures ranging from 15° to 34^° C. (59° to 91.1° 
F.) were used. There was a degree or two of variation between the 
temperature of setting and that of pouring. The average tempera- 
ture is given in the table. The method of making was the ordinary 
one previously described. The results are seen in Table 3. 
It is noticeable that the losses of fat increase in the samples with 
the higher percentages of fat, and that the losses with the low- 
setting temperatures are somewhat high. A temperature below 
25° C. (77° F.) or much above 30° C. (86° F.) did not prove desirable 
for the setting of either type of cheese. 
