whilst the process goes on. In the process of fermentation, Dr.
Chittenden says the beans are "stewed in their own juice." This may be
expressed less picturesquely but more accurately by saying the beans are
warmed by the heat of their own fermenting pulp, from which they absorb
liquid.

In Trinidad the cacao which the girls have scooped out into the baskets
is emptied into larger baskets, two of which are "crooked" on a mule's
back, and carried thus to the fermentary. In Surinam it is conveyed by
boat, and in San Thome by trucks, which run on Decauville railways.

The period of fermentation and the receptacle to hold the cacao vary
from country to country. With cacao of the criollo type only one or two
days fermentation is required, and as a result, in Ecuador and Ceylon,
the cacao is simply put in heaps on a suitable floor. In Trinidad and
the majority of other cacao-producing areas, where the forastero
variety predominates, from five to nine days are required. The cacao is
put into the "sweat" boxes and covered with banana or plantain leaves to
keep in the heat. The boxes may measure four feet each way and be made
of sweet-smelling cedar wood. As is usual with fermentation, the
temperature begins to rise, and if you thrust your hands into the
fermenting beans you find they are as hot and mucilaginous as a
poultice.

[Illustration: "SWEATING" BOXES, TRINIDAD.
The man is holding the wooden spade used for turning the beans.]

   _Time._      _Temperature._
When put in   25 deg. C. or  77 deg. F.
After 1 day   30 deg. C. or  89 deg. F.
After 2 days  37 deg. C. or  98 deg. F.
After 3 days  47 deg. C. or 115 deg. F.

(After the third day the heat is maintained, but the temperature rises
very little.)


The temperature is the simplest guide to the amount of fermentation
taking place, and the uniformity of the temperature in all parts of the
mass is desirable, as showing that all parts are fermenting evenly. The
cacao is usually shovelled from one box to another every one or two
days. The chief object of this operation is to mix the cacao and prevent
merely local fermentation. To make mixing easy one ingenious planter
uses a cylindrical vessel which can be turned about on its axis.

[Illustration: FERMENTING BOXES, JAVA.
From the last box the beans are shovelled into the washing basin.
(Reproduced from van Hall's _Cocoa_, by permission of Messrs. Macmillan
& Co.)]

In other places, for example in Java, the boxes are arranged as a series
of steps, so that the cacao is transferred with little labour from the
higher to the lower. In San Thome the cacao is placed on the plantation
direct into trucks, which are covered with plaintain leaves, and run on
rails through the plantation right into the fermentary. Some day some
enterprising firm will build a fermentary in portable sections easily
erected, and with some simple mechanical mixer to replace the present
laborious method of turning the beans by manual labour.

The general conditions[1] for a good fermentation are:

(1) The mass of beans must be kept warm.

(2) The mass of beans must be moist, but not sodden.

(3) In the later stages there must be sufficient air.

(4) The boxes must be kept clean.

    [1] For full details see the pamphlet by the author on _The
        Practice of Fermentation in Trinidad_.



_Changes during Fermentation._

No entirely satisfactory theory of the changes in cacao due to
fermentation has yet been established. It is known that the sugary pulp
outside the beans ferments in a similar way to other fruit pulp, save
that for a yeast fermentation the temperature rises unusually high (in
three days to 47 degrees C.), and also that there are parallel and more
important changes in the interior of the bean. The difficulty of
establishing a complete theory of fermentation of cacao has not daunted
the scientists, for they know that the roses of philosophy are gathered
by just those who can grasp the thorniest problems. Success, however, is
so far only partial, as can be seen by consulting the best introduction
on the subject, the admirable collection of essays on _The Fermentation
of Cacao_, edited by H. Hamel Smith. Here the reader will find the
valuable contributions of Fickendey, Loew, Nicholls, Preyer, Schulte im
Hofe, and Sack.

The obvious changes which occur in the breaking down of the fruity
exterior of the bean should be carefully distinguished from the subtle
changes in the bean itself. Let us consider them separately:--

(_a_) _Changes in the Pulp._--Just as grape-pulp ferments and changes to
wine, and just as weak wine if left exposed becomes sour; so the fruity
sugary pulp outside the cacao bean on exposure gives off bubbles of
carbon dioxide, becomes alcoholic, and later becomes acid. The acid
produced is generally the pleasant vinegar acid (acetic acid), but under