282 
The Worli of Acidity in Clieese-niaJdng. 
are the primary effects of acidity and of its excess or deficiency 
on the curd produced in railk by rennet. From the results thus 
obtained it is not difficult to form a general idea of what will 
be the secondary or remote effect of the three conditions on the 
curd when it comes to be separated from the whey and to be 
handled as it reqiiires to be in order to convert it into a compact 
cheese. But the practical working-out of this problem is scarcely 
more difficult than the experiments which we have already de- 
scribed. All that is necessary is to take quantities of milk 
which are sufficient to give such an amount of curd as can be 
conveniently handled ' ; to drain the whey off the curd after the 
latter has been gradually reduced to small fragments by cutting 
or breaking with the fingers ; to then press these fragments 
into any convenient mould, so as to weld them into a uniform 
mass, and, in fact, to treat the samples of curd generally in the 
way in which curd is dealt with in making any ordinary type 
of hard cheese. One point in this after-treatment is essential 
in order to produce results whic)i shall be comparable with one 
another and with those obtained in ordinary cheese-making, and 
this is that the curd shall in each case be maintained as nearly 
as possible at a uniform temperature, commencing at about 
90° F. and falling gradually to about 05° F., at which tem2)era- 
ture the compacted cheese should be maintained as long as is 
practicable.^ 
Let us now assume that we have convei*ted tlie curd of the 
four samples of milk, treated as first described, into four cheeses ; 
that we have handled these miniature cheeses in the way in 
which larger ones would be treated after they are taken from 
the cheese- vat or mould ; and that we have kept them suffi- 
ciently long to allow of their undergoing those fermentative 
changes in which the process of ripening consists : what will be 
the differences, if any, which we shall observe in them ? 
To take first the curd obtained from the spontaneously soured 
milk : we shall find, at the outset, that it will have so low a 
degree of tenacity that it will be difficult to get it to cohere into 
a compact cheese at all. If we succeed in doing so, the cheese 
' One gallon of milk is ample for this purpose in each case, and less can be 
made to do with a little practice. 
■•' It lias not been thought necessary to give precise instructions here as to the 
treatment of the curd in this series of experiments, as anyone with even a 
slight acquaintance with practical cheese-making will be able to judge from 
his own experience how to proceed. A hot-air chamber sutlituent for the 
purposes of the experiments above suggested can be constructed out of an old 
biscuit tin, in which two or three hol&s are made as inlets and outlets of 
the products of combustion of a small bcnzolinc lamp and for the introduction 
of a thermometer. 
