258 Milk and Its Products 
the part that was uppermost comes in contact with 
the bottom of the vat. A further draining of the 
whey takes place, and the blocks of curd are next 
piled upon one another two deep, care being taken 
in forming these piles that the parts that were ex- 
posed to the air are turned in. Later on the curd 
is piled again in still deeper piles, and as the pro- 
cess continues the mass is piled over and over 
again, care being taken that the exposed parts of one 
pile are put into the interior of the succeeding, so 
that the heat may be uniform throughout the whole 
mass. In the curd sink the manipulation is not 
essentially different. The curd sink is a square 
wooden receptacle fitted with a false slatted bottom 
and covered with coarse cotton or linen cloth, 
through which the whey can easily escape. When 
the time comes for separating the whey, so much 
as will run off readily is drawn off, and the re- 
maining whey, mixed with particles of curd; is 
dipped into the sink, the whey runs off freely 
through the strainer and slatted bottom, and the 
curd, being spread over the whole surface of 
the sink, soon mats into a solid mass, and the 
piling process goes on the same way as is done 
in the vat. During this process various changes 
take place. The pressure of the particles of curd 
upon one another serves to expel a large part of 
the whey that still remains; at the same time the 
temperature is kept sufficiently high so that the 
production of lactic acid is not checked. The effect 
of the acid is to cause a series of marked changes 
