MANUFACTURE OF CASEIN. 17 
cloth is not strong enough to make a satisfactory drain cloth. Two 
pieces of 36-inch burlap three yards long, sewed together at the 
middle with a treble seam, make a drain cloth of suitable size for a 
drain rack 3 feet wide, 6 feet long, and 12 inches deep. The edge of 
the cloth should be hemmed to prevent raveling and unnecessary 
wear. 
For pressing the wet curd 10-ounce duck seems to be most satis- 
factory, since it has the greatest strength, is easy to wash, and does 
not allow the curd to escape. Burlap of a very close weave can be 
used, but is much harder to wash. Unbleached muslin is satisfactory 
but does not equal the cluck. Any of the materials mentioned can 
be obtained in widths suitable for making cloths of the proper size 
to use with the curd press and dividing boards described. Pieces 41 
inches long, cut from a 40-inch bolt, after the torn edge has been 
hemmed to prevent raveling, make cloths of suitable size for a form 
20 inches square and 8 inches deep. 
FACTORS INFLUENCING THE QUALITY OF BUTTERMILK CASEIN. 
The difference and variation in chemical composition and physical 
condition of buttermilk make it hard to control absolutely all condi- 
tions which may influence the quality of the casein. In making the 
different lots of buttermilk casein conditions were controlled so far 
as was practicable, so that the factor studied was the only variable 
introduced. That makes it possible to observe, on a fair and com- 
parative basis, the effect of any factor under consideration. 
The factors that have an important influence upon the quality of 
the buttermilk casein are: 
Fat content of buttermilk. 
Washing the precipitated curd. 
. Temperature of drying the ground curd. 
Temperature of precipitating the curd. 
Acidity of buttermilk at the time of precipitation. 
FAT CONTENT OF BUTTEKMILK. 
Since all the fat originally in the buttermilk is concentrated in the 
dried casein it probably will have a deleterious effect upon the 
strength and general working properties of the casein. An increased 
quantity of fat yields not only a casein of poorer solubility and 
strength, but also a solution of poorer physical qualities. A lot of 
buttermilk was divided into two parts and fat in the form of cream 
added to one part, which was used as a basis for observing the effect 
of increased fat content upon the quality of the casein. 
