MANUFACTURE OF CASEIN. 9 
occasional runs are made, the cost is considerably higher than when 
the volume of business carried on is sufficient to permit the most 
efficient and economical use of labor and equipment. If 10,000 or 
more pounds of buttermilk is handled daily the cost of making dried 
casein should not exceed 3 cents a pound. 
The cost of making casein from skim milk is less than that from 
buttermilk, as it does not require nearly so much work. Several 
concerns that were making a large quantity of skim-milk casein 
regularly estimated that the cost of manufacture was between 1 and 
1J cents a pound, although they had no detailed cost-accounting 
figures. It is probable that the cost will be more than is ordinarily 
estimated by those without definite figures, since, in figuring it, the 
depreciation and the interest on the cost of equipment should be 
included with the expense of labor, steam, and other items. 
EQUIPMENT REQUIRED. 
For making buttermilk casein, the necessary apparatus, besides the 
storage tank and precipitating vat which are already available in 
most creameries, consists of the following : 
Drying tunnel with fan blower and heating coils. 
Drying trays. 
Trucks for holding the drying trays. 
Curd mill. 
Curd press. 
Press dividing boards. 
Drain rack. 
Cloths for draining and pressing the curd. 
Practically the same equipment is needed for making skim : milk 
casein, with the exception of the drain rack, which ordinarily is not 
used. 
It is advisable to make the tunnel drier larger than the imme- 
diate demands require. When being constructed this can be done at 
comparatively little additional expense and it allows, without incon- 
venience, expansion of the plant. The remainder of the equipment 
can be increased easily at any time. 
Many creameries that do not have buttermilk enough to warrant 
putting in the complete drying apparatus precipitate the curd, press 
a large part of the moisture out, and sell it in that condition. In that 
case the curd is received at a central plant where it is ground and 
dried. If a market can be obtained for the wet curd the only addi- 
tional apparatus required, besides the vats, are the drain rack, curd 
press, dividing boards, and the cloths for draining and pressing, all 
of which are available at comparatively small expense. The item 
of greatest cost is the apparatus for drying the casein, which consists 
of the drying tunnel with fan blower and heating coils, drying trays, 
39637°— 18— Bull. 661 2 
