pt warm or it will solidify
and much time and heat (and possibly temper) will be absorbed in
remelting it; for this and other reasons most chocolate factories have a
number of hot rooms, in which the chocolate is stored whilst waiting to
pass on to the next operation. The dry powder coming from the rolls is
either taken to a hot room, or at once mixed in a warm _melangeur_,
where curiously enough the whole becomes once again of the consistency
of dough. The grinding between the rolls and the mixing in the
_melangeur_ are repeated any number of times until the chocolate is of
the desired fineness. Whilst there are a few people who like the clean,
hard feel of sugar crystals between the teeth, the present-day taste is
all for very smooth and highly refined chocolate; hence the grinding
operation is one of the most important in the factory, and is checked at
the works at Bournville by measuring with a microscope the size of the
particles. The cost of fine grinding is considerable, for whilst the
first breaking down of the cacao nibs and sugar crystals is
comparatively easy, it is found that as the particles of chocolate get
finer the cost of further reduction increases by leaps and bounds. The
chocolate may now proceed direct to the moulding rooms or it may first
be conched.

[Illustration: GRINDING CACAO NIB AND SUGAR.
(Messrs. Cadbury Bros., Bournville).]

[Illustration: SECTION THROUGH CHOCOLATE GRINDING ROLLS.]

(_d_) _Conching._

We now come to an extraordinary process which is said to have been
originally introduced to satisfy a fastidious taste that demanded a
chocolate which readily melted in the mouth and yet had not the cloying
effect which is produced by excess of cacao butter. In this process the
chocolate is put in a vessel shaped something like a shell (hence called
a _conche_), and a heavy roller is pushed to and fro in the chocolate.
Although the conche is considered to have revolutionized the chocolate
industry, it will remain to the uninitiated a curious sight to see a
room full of machines engaged in pummelling chocolate day and night.
There is no general agreement as to exactly how the conche produces its
effects--from the scientific point of view the changes are complex and
elusive, and too technical to explain here--but it is well known that if
this process is continued for periods varying according to the result
desired from a few hours to a week, characteristic changes occur which
make the ch