From the Archives
of the Rare Fruit Council of Australia, inc.
by Ted Henty, Lae, P.N.G.
seeds ('beans') have no chocolate flavour when fresh. In normal
plantation practice, flavour is produced by natural fermentation,
usually in large (say 1 x 2 m x 1 m high) wooden boxes. The pods are
broken, and the beans, with the sweetish pulp surrounding them,
decanted into the boxes.
The mass soon begins to ferment, and a
good deal of liquid drains away, in the early stages, through holes of
about 1 cm diameter in the bottom boards.
After 2 days, the
beans are turned out into another box, to mix and aerate them, and this
is repeated each day until fermentation is finished, in 6-8 days. The
beans are then turned out and dried.
During fermentation, the
temperature should rise to about 50°C. Small amounts of beans will
not heat sufficiently. The smallest effective size for a box is about
60 x 60 cm, and about 1 m high; this should be filled to at least 60 cm
(about 90 kg of wet beans).
As fermentation proceeds, the beans,
which are purple inside in the most familiar variety, become lighter in
colour and finally brown. In well-fermented cocoa, the seed-coat is
loose, and the cotyledons are easily broken into segments.
Urquhart, in his book Cocoa (Longmans, 1955), describes artificial
fermentation, used to assess the flavour of small batches, single pods
or even individual beans. The pods were swabbed with an antiseptic,
then opened under aseptic conditions. Fermentation was started with a
mixed bacterial/yeast culture, or dispensed with; its only effect was
as a source of heat, and chocolate flavour could be produced by
manipulating the temperature in an incubator. Germination (or its early
stage) was found to be essential; dead beans, killed by heat or cold,
would not develop flavour.
Urquhart recommends a temperature of
35°C (not above 38 °) for the first 3½ days, rising then
to 50°C for another 3 days.
The beans must be in a container of
non-reactive material (not metal, but glass, plastic, or un-chipped
enamel) in a water-bath (e.g., a laundry copper) for easier temperature
A false bottom must be placed in the vessel, to allow
separation of liquid, and the beans stirred thoroughly every 24 hours
(at least until 24 hours after the rise to 50°C) to remove carbon
Probably asepsis is not vital. In the first few days
the seeds are alive and can resist infection; after the temperature
rises to 50°C, most organisms will be killed anyway.
had no personal experience of small-scale fermentation of cocoa. It is
to be hoped that someone may build a method on the information given
here, and pass on some more explicit advice in the future.