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 duck. 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 BUTTERMILK. 



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. 



