434 
THE TROPICAL AGRICULTURIST. [December i, 1890. 
Theobromine ... ... 2 
Other sub.stances (includ- 
ing in one observer humic 
acid 7) ... ... 11 
Total ... 100 
This relative composition of the different varieties of 
cocoa is maintained whether in the green state, fer- 
mented, or roasted. Are we not then justified in 
deciding that no chemical changes are brought about in 
the bean by fermentation, or at any rate none that 
can be formulated ? 
The ingredient ulmine or humic acid is a curious 
discovery, and one would fanoy straight away that it 
was derived from Sugar ! But that cannot be, for 
the starch granules within the bean are not changed 
into Sugar. Mr. Prestoe thought that the sweating of 
cocoa was a maltirrg process (vide Annual Beport of 
Bo'anio Gardens for 1880, para. 337), and many 
planters still think that germination has something to 
do with it ; if so, it can be but in the very earliest 
stage, inasmuch as the radicle is always t?i situ: it 
may influence the swelling out of the bean which always 
takes place in the sweating house, and that is about 
all. When the vinous fermentation sets in, germina- 
tion is arrested. At this stage, if fermentation has been 
properly established, the cotyledons are found separated 
and the vinous liquor of the pulp, which joasses through 
the membranous covering, occupies this space, as well 
as the lacun® between the convolutions, the cocoa bean 
being distinguished as foliaceous. This it is which has 
so marked a physiological influence and affects its 
flavour, the bean being, as may be said, cuite dans 
ton jus. 
This phenomenon is described chemically as 
“ osmosis,” and may be shown in a very simple manner 
by placing the fermenting beans in a solution of fuch- 
shine, which passes inside at once. 
When the cocoa is eventually dried — in the sun or 
otherwise — the fluid, of course, disappears, but the 
lacuna remain, and are the cause of the elastic feeling 
on pressure which some buyers hold by so much. It 
is thesiyn of fermented cocoa. If the following axioms 
are admitted, viz.: — 
1. The different requirements of our cocoa with regard 
to fermentation are mainly regulated by the amount 
of fat they coutaiu. 
2. It is not possible to separate the varieties in the 
field for practi«il purposes, 
we may proceed to consider Mr. Striokland’a method. 
He has a series cf vats or tanks (3) in a row, built of 
concrete. They are 11 feet wide, 5 feet deep, and 
about 22 feet long, (the row of three) ; they are covered 
by a galvanised iron roof, but the shed is not boarded 
up from the level of the tanks to the roof (about 5 
feet), there is a vent, of course, below for the escape 
cf liquor, and the cocoa is covered carefully on top 
with plantain leaves ; there is no other cover. 
The drainage fiom these tanks runs away to a little 
pond and stinks quite as bad as the lees from a sugar 
battery. One caunot help thinking this is a foolish 
waste ot good material, for if the pleasant tasting 
vinous liquor cannot be used as a beverage, why not 
convert it into vinegar ? 
The cocoa remains in the first vat five days, and the 
temperature is not allowed, under any circumslances, 
to rise beyond 115° or 120° (by thermometer); this is 
regulated by the admi-sion of cold air through bamboo 
tubes, wi'h many openings (6 bamboos in each tankl, 
with their ends protruding tbrougli holes in the concrete 
wall at eacli end of the tank ; the ends of the tubes are 
plugged with c'ay when required to modify tho current 
r>f cold air — a reugh and ready plan, but quite oft'i ctual. 
Xu thin tank the evolution of carbonic acid gas is very 
marked, and iniiy be easily demonstrated by eomiecting 
the ends of the bainbo s with a glass filled with lime 
water. 'J’licre is also a delicious odour from the ferment- 
ing inaKs, as of apples or cider. Tho vinous fermenta'ion 
in this vat induced by “ saccharoinyces ccrviciae ” (Alls 
acooinjianied before r.-inoval probably by a commenc- 
ing lactous lermentaliou, tho ferment of which is 
“ penicillium glaucum,” 
C, H,2 Oe=^2 0, Ha Oa 
The cocoa is next turned over to vat No. 2, and about 
this time a marked acid reaction is shewn by the red- 
dening of litmus paper. The lactous fermentation 
may then go on alone at a somewhat lower temperature, 
and after another five days the cocoa is turned into 
vat No. 3. Here, some very complex changes take 
place, such as the conversion ot lactic into butyric acid, 
2 O3 He Oa^Ce H, Oj+2 C 0,-l-2 Hj 
The pleasant cider-like smell of the vinous ether has 
vanished, and it is curious that it should be replaced 
by its isomer (Butyric Acid). The latter is familiar 
as the four smelling substances met with in rancid 
bulttr. The presence of butyrates in this vat is very 
easily shewn. One must be careful that at th's stage 
the temperature does not fall below 95°, and even then, 
some of the secondary fermentations must take place, 
(which some people think might be left out, for fear of 
spoiling the flavour of the bean) such as the mucous 
and putrefactive, with vibrio and the formation of 
nitrous and nitric acid, and at times the evolution of 
offensive gas, the beans becoming discoloured and 
covered with algsa. After fire days in this vat the 
cocoa is removed to the drying house, where three 
days’ exposure to the sun sutficea to dry and finish its 
preparation. The cocoa has then decidedly not an 
inviting appearance, it is dark, somewhat shrivelled, 
not too elastic on pressure, and even sour smelling, 
but this sour smell is certainly not the common sour 
smell which is condemned in inferior cocoa. It is by 
ceotion only that the advantage of this process can be 
seen, and then you will find a characteristic light 
cinnamon colour, an agreeable odour, and every bean 
uniform — not a purple or yellow bean, even amongst 
the flattest and most unpromising. This is what the 
manufacturers want, and it is the only way known at 
present to get over the difficulties of sweating the 
many varieties of our cocoas. It may, however, be 
suggested that the outward appearance of this cocoa is 
susceptible of improvement; and with this view wash- 
ing might be tried, and the cocoa afterwards sprinkled 
with a solution of boric acid to prevent mildew. If 
treated with this or some similar antiseptic such as 
sulphurous acid (fuming sulphur) “ as suggested by 
Mr. Frestoe,” it might be diied in a current of air 
without any exposure to sun at all and would resht 
damp for many days, but if dried by artificial heat 
such as that of Mr. Boss of Oi enada, (dry heat) or hot 
water apparatus, the risk would be still less. This 
plan would be applicable to all cocoas, of CDurse, with- 
out respect to the period of fermentation, and in wet 
weather it would be fuuud a very great advantage to 
remove the mass of sour gummy substance, although 
this may act as a preservative coaling when the coc^a 
is sun-dried. The husk is certainly much more brittle 
in washed cocoa, and does nut therefoie protect the 
bean as it should; it weighs also considerably lighter, 
but this might be made up by ? e-coating the bean with 
a mixture of starch, gum tragacautb, and boric acid. 
This would be preservative, and improve the look of 
the cocoa very much ; colour might be added if 
desired. If so, it should be red earth and not common 
colouring material, because earth coating is recognised 
as legitimate. Some might prefer the fresh cocoa pulp ; 
if so, boric acid should still be an ingredient, and the 
proper way would be to sprinkle during the drying 
proce.'s, and not wash on in quautit}’. One favourable 
poiut in the removal of the fusty products of fermen- 
tation before drying would be the saving of infinite 
labour in treating and hand rubbing the cocoa as usually 
practised. The boric acid might be added in the pro- 
porfon of 1 per cent. 
Rem auu tetigisti.’’ 
Second Piuze Essay. 
» # # * » 
After picking, the po.ls are gathered info heaps, this 
heaping being a first step in the process, and one 
requiring special attention. 
Tho time fermentation in the pod is allowed to take 
place varies aocording to the state of the weather, for 
