8 BULLETIN 661, U. S. DEPARTMENT OF AGRICULTURE. 



REMOVING DRIED CURD OR CASEIN FROM THE TRAYS. 



When the curd has been properly ground and uniformly spread 

 upon the trays the finished casein comes from the drier in good 

 physical condition and it can be collected easily by turning the trays 

 over a bin and giving them a slight jar. If grinding and drying con- 

 ditions have been unfavorable the casein does not come from the 

 trays so easily, as it does not have the same granular form and has 

 more tendency to stick to the screening. This is especially true in 

 the case of a high-fat buttermilk curd which has not been washed 

 sufficient^ to remove the sugar and other soluble impurities. 



GRINDING AND PACKING CASEIN. 



It is advisable to grind and screen the casein after it comes from 

 the drying tunnel in order that it may be of uniform grain and 

 appearance. In the marketing of casein uniformity is of as much 

 importance from the standpoint of appearance as in the case of 

 other products. Grinding a coarse-grained casein makes the color 

 considerably lighter, which is much desired. For grinding, a small 

 burr-feed grinder gives satisfactory results and can be procured at 

 small expense. The finished casein is placed in strong burlap or 

 grain sacks in which it is shipped to market. Care must be taken, 

 while awaiting shipment, to store the casein in a dry place where, 

 if properly made, it will keep for several months. 



YIELD OF BUTTERMILK CASEIN. 



Depending upon its physical condition at the time of precipita- 

 tion, 100 pounds of undiluted buttermilk yields on the average from 

 2.8 to 3.1 pounds of dried casein. Coagulated buttermilk which has 

 been broken up by mechanical agitation, such as pumping or stirring, 

 gives a very fine curd, much of which is liable to be lost through the 

 drain cloth. In ascertaining the yield, the quantity of water added 

 to the cream in rinsing the vat and utensils should be taken into con- 

 sideration if correct figures are desired. In many creameries the 

 cream is diluted with an unnecessarily large quantity of water before 

 it reaches the churn, and in such instances the }deld of casein, based 

 on the actual weight of the diluted buttermilk, is considerabl3 r lower. 



COST OF MANUFACTURE. 



No definite figures can be given on the cost of manufacturing, as 

 cost-accounting data were not kept when a sufficient quantity of 

 buttermilk was handled to give results applicable to ordinary cream- 

 ery conditions. The cost of making is governed largety by the volume 

 of business. When, in order to take care of surplus material, only 



