112 Report OF THE CHEMIST OF THE 
and about 8 hours later rennet extract is added at the rate of 
about 1 ounce for 1,000 pounds of milk. The rest of the opera- 
tion is completed as described under (3) above. 
(6) Manufacture of cottage cheese by direct addition of hydro- 
chloric acid.—The milk should be at a temperature between 70° 
F. and 80° F. (21° C. and 27° C.). Measure out hydrochloric 
acid, of specific gravity 1.20, at the rate of 10 ounces for 100 
pounds of milk, dilute this with ten times its bulk of water and 
add to the milk gradually, stirring the milk constantly while the 
acid is being added. The stirring is continued until the curd 
separates fully, leaving a clear whey entirely free from milkiness. 
As soon as this is accomplished, the whey is run from the curd and 
the rest of the operation completed as described under (3) above. 
Some care should be exercise in regard to the quality of the 
hydrochloric acid used. The kind usually kept at drug stores is 
not pure enough. The right kind of hydrochloric acid can be 
obtained from the Baker & Adamson Chemical Co., Easton, Pas 
by ordering “hydrochloric acid, ¢. p., sp. gr. 1.20,” and the cost 
in 5 pt. bottles is 744 cents net a pound, or in carboys at 7 
cents net a pound. 
QUALITIES OF COTTAGE CHEESE. 
The qualities that determine in the greatest degree the value 
of cottage cheese as an article of commerce are flavor and text- 
ure. The flavor should be that of mildly soured milk or well- 
ripened cream. There should be an entire absence of all 
objectionable flavors, such as bitter taste, flavor of stable, ete. 
If the cheese tastes too sour, it is probably due to the retention 
of too much whey. The use of a good starter will usually 
insure the right kind of flavor. The texture of cottage cheese, 
as we have already pointed out, is largely dependent on the 
amount of moisture retained in the cheese, and this in turn, is 
dependent largely upon the temperature at which the curdled 
mass of milk is heated and the length of time the heat is 
applied. Heating the coagulated mass above 100° F. (38° C.) 
for a very short time will make the cheese too dry and the text- 
ure crumbly. Heating below 90° F. (32° C.) for too short a 
time will make it impossible for the whey to drain from the curd 
satisfactorily and the cheese will be soft and mushy. For the 
