In selecting rennets to soak, all discolored and bad smelling ones
should be scrupulously rejected. But rubbing rennets is a disagreeable
and disgusting business, and it is somewhat difficult to keep your
rennet of uniform strength. Therefore, if good rennet extract can be
bought at a reasonable price, we would recommend its use. It ought to
be made better and cheaper in a wholesale way than in little batches
at each factory. To guard against imposition, one should buy only of
known reputable dealers. Preparing your own rennet is much like doing
your own shoe making. It doesn't pay, if you have got anything else
remunerative to do.