Soaking in whey, containing all its taints and impurities, is the
source of a vast amount of foul rennet and off-flavored cheese. If whey
is used, it should be boiled to kill taints and precipitate, as far as
possible, the solids remaining in it. But, do the best that can be done
with it, and still whey is objectionable for soaking rennets, because
of the acid that develops in it from the presence of sugar. This acid
neutralizes a corresponding amount of rennet and helps to impoverish
the cheese. Indeed, if carried far enough before the curd is removed
from it, the finer flavoring oils are cut by it, the phosphates are
dissolved, and these pass out with the whey, leaving the cheese but
little better than an indigestible mass. If the acid adds solidity to
the cheese, it does it by removing from it valuable ingredients.