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Cornell University

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The original of this book is in
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There are no known copyright restrictions in
the United States on the use of the text.

http://www.archive.org/details/cu31924016404505

THE FERMENTATION OF CACAO.

A PRoLiFIC CACAO TREE IN ParA, BRAZIL.

(Give us Agricultural Colleges in the Tropics at which to
train our future planters and experts, and such trees will
then be the rule, not the exception. ]

THE

FERMENTATION OF CACAO

WITH WHICH IS COMPARED .THE RESULTS OF EXPERIMENTAL
INVESTIGATIONS INTO THE FERMENTATION, OXIDATION, AND
DRYING OF COFFEE, TEA, TOBACCO, INDIGO, &c., FOR SHIPMENT

: By the following Authorities :—
Dr. AXEL PREYVER, Bertin Dr. SCHULTE IM HOFE, Bertin

Dr. OSCAR LOEW, Mounicu Dr. J. SACK, Hottanp
Dr. FICKENDEY, Cameroons Mr. GEO. S. HUDSON, Sr. Lucia, B.W.1.

Dr. LUCIUS NICHOLLS, or CamsrincE (Enc.) anp Str. Lucia

EDITED BY

HAROLD HAMEL SMITH

Editor of ‘* Tropical Life” ; Author of “ Sott and Plant Sanitation on
Cacao and Rubber Estates” ; ‘‘ The Future of Cacao-Planting” ;
‘‘ Cacao-Flanting in the West Indies,” &c., &.

WITH A FOREWORD BY
Sir GEORGE WATT, C.LE., M.B., C.M., LL.D., F.LS.,

Formerly Reporter on Economic Products to the Government of India ;

Author of “ The Dictionary of Economic Products of India” ; * The Pestsand Blights
of the Tea Plant”; ‘The Commercial Products of India”; “ The Wild and Culti-
vated Cotton Plants of the World” ; “ Indian Art.at Dethi in 1903,” &¢., &c.

CONTAINING 35 ILLUSTRATIONS

LONDON
“TROPICAL LIFE” PUBLISHING DEPARTMENT

JOHN BALE, SONS AND DANIELSSON, LTD.
83-91, GREAT TITCHFIELD STREET, OXFORD STREET, W.

Works by the same .Author.

The Future of Cacao Planting.

With Foreword by Sir Danie Morris, K.C.M.G.,
formerly Imperial Commissioner for Agriculture in
the West Indies. Crown 8vo, price 1s., post free
1s. 2d.

Soil and Plant Sanitation on Cacao
and Rubber Estates. .

With separate complete Sections devoted to Ceara
Rubber Cultivation, Castilloa Rubber Cultivation,
Funtumia Rubber Cultivation and Rubber
Tapping, and Foreword by Professor WyNDHAM
‘Dunstan, C.M.G.,, M.A., &c., &c., Director of the
Imperial Institute; President of the International
Association of Tropical Agriculture, in which the
establishment of Agricultural Colleges in the
Tropics is warmly advocated. Over 100 illustra-
tions, price 10s. net; 11s. post free.

Aigrettes and, Birdskins.

The truth, about their collection and export.
With a Foreword by Sir J. D, Regs,. K.C.1.E.,
C.V.O., M.P. 4to, 138 pp., price 5s, net.

JOINT AUTHOR WITH F. A. G. PAPE OF

Coco-Nuts: The Consols of the East.

With many illustrations and some original sketches
by Mr. Paps, and Foreword by Sir W. H. Lever,
Bart. Price 10s. net.

FOREWORD.

THE FERMENTATION OF CACAO.
By Sir GEORGE WATT, C.LE., LL.D., F.LS., &c.

I wave read every word of your work on the
Fermentation of Cacao with absorbing interest,
and must congratulate. you on being able to
bring out a book that will become a classic on
the subject it deals with so very ably. You
have brought together the opinions of several
experts of scientific eminence and practical
experience, and these must be drawn upon by
all subsequent investigators until finally there
is evolved something definite and of universal
acceptance.

Here and there there are differences of
opinion among your authors, as you yourself
have pointed out, but in many cases these will
be resolved into the effects of variations in
climate, soil, water, variety of plant, or such
like simple causes. In other words, the
differences are more in the theories formed
than in the observations made. I believe the
entire industry of grawing and curing cacao
is very largely groping in the dark. There
are a hundred and one directions of future

vie The Fermentation of Cacao

improvements, many of these hardly less
important than the so-called fermentation of
the seed, as a stage in its curing (plantation
manufacture).

Over thirty years ago, when I first took up
the study of the cultivation and manufacture of
tea, that industry was then in the very position
of cacao to-day. We have reduced the area of
cultivation but increased the outturn; we have
improved the quality but reduced the cost.
These are great triumphs of scientific precision
as also of inventive ingenuity brought to bear
on tea, but the same thing can be and will
be accomplished with cacao. It seems to me
possible that far too much merit is attributed to
fermentation. That fermentation is necessary
with the presently accepted method of curing
goes without saying, but I would not be
surprised were a new process introduced where
fermentation could be entirely discontinued.
The parallel with tea is worthy of the most
careful study. But it is perhaps useless to
speculate ; the opinions your authors advance
are certain to be tested at the plantations, and
out of the new experience thus gained must
evolve the future system of manufacture.

PREFACE.

I Have placed the essays. in the order in
which they will be found in accordance with
the dates when they were first published. As
I wish to acknowledge to whom I am indebted.
for the permission to reproduce them, and also
wish to refer my readers to the originals in
case they should wish to consult them, |
cannot do better than to thank, the journals,
and to give the necessary list at the same
time, as follows :—

(1) Dr. Axel Preyer's article will be found
in Der Tropenpfianzer, No. 4, of April, 1901,
pp. 157-173. The translation, made by my
brother Victor and M. Ulrich Hugentobler, .
originally appeared in Zvopzcal Life.

(2) Dr. Oscar Loew’s essay is taken from
Bulletin No. 1093 of the United States
Department of Agriculture (Office of Experi-
-ment Stations), and first appeared in the
Annual Report of the Porto Rico Agricultural
Experiment Station for 1907.

(3) Dr. Fickendey’s (Director of the
Experiment Station, Victoria, Cameroons,
German West Africa) was taken from
Der Tropenpflanzer, No. 2, of February,
1909, pp. 87-90; and I am indebted to

Vill. The Fermentation of Cacao

Dr. Ronald Krohn, of Hampstead, for the
translation.

(4) Dr. A. Schulte im Hofe’s essay was
included on the recommendation of Dr.
Matthiesen, of the Kolonial-Wirtschaftlichen
Komitee, of Berlin, to whom, as to Professor
Dr. Otto Warburg, my thanks are due for
this and other help given. The essay was
published in 1908 by Herr Dietrich Reimer
(Ernst Vohsen), .of Berlin, as a_ separate
pamphlet. Dr. Ronald Krohn also trans-
lated this essay.

(5) Dr. J. Sack’s article was included on
the recommendation of Dr. Dekker, of the
Colonial Museum, Haarlem, to whom thanks
are due for this and other forms of help. The
translation was done under his supervision in
Holland.

(6) The essays contributed by Mr. Geo. S.
Hudson, of Errard Estate, St. Lucia, British
West Indies, and Dr. Lucius Nicholls, until
recently in Government employ in the same
island, was brought into being through the
help and generosity of a number of readers
of Tropical Life, who, like myself, were
interested in the question of the fermentation
of cacao, and anxious to see whether the out-
put, especially from those centres where the
bulk of the producers were small peasant pro-
prietors, could not be improved and equalized,
so as to be shipped and purchased “to type,”
instead of being made up of a number of small,

Preface ix.

and very small, parcels, often down to 1 lb. or
2 Ib. each, no two beans of which, when picked
up at random, had any points in common, and,
therefore, extremely unsatisfactory to roast up
and use, compared to the large parcels pro-
duced in, and purchasable from, such centres
as San Thomé and Bahia.

What we particularly want to avoid, and
what I hope the experiments described in this
book will help us to do away with to a large
extent, are the uneven and unsightly rows of
cacao samples to be seen on the counter of any
broker or dealer when offering such produce
for sale. Anyone with a month’s experience
of the cacao trade will know the sort of lots
I refer to; beans bright, dull, or grey mouldy
and reddish; dark beans, black, mouldy, and
fiery red lying side by side, and far too often
mixed in the same tray or heap. Here is a
lot with a thin, light, almost straw-coloured
shell nearly as pale as cardamoms, there are
some Haitians or San Domingo, with a coat-
ing of mould over them that would be a
credit to a bottle of fine old crusty port. In
any case no two bags or trays are alike,
and the samples themselves show a most
regrettable mixture of colours and qualities
that should not be, since such a defect could
be so easily avoided, and will be, I trust,
after the results of the suggestions offered
in the following pages have been tested and
carried .on to a final conclusion.

x. The Fermentation of Cacao

Great strides have been made of late years
in the quality of the beans exported from the
Gold Coast, but, in face of the improvements
introduced in Grenada cacao since that island
came to the front as a leading exporting
centre, one can-still see that there is much
room. for improvement in the African beans at
times, and I anticipate seeing a steady and
continuous levelling-up in its quality as regards
evenness, colour, and general appearance until
it can compete in external appearance ‘with San
Thomé and leave it behind for flavour, aroma,
and freedom ‘from hamminess. But there is
much to be done before this is achieved, as
was forcibly driven home to my _ notice’ ‘the
other day when valuing some lots from the
Gold Coast, the beans of which were most
miserable. Mouldy, greyish, lean, small, ill-
kempt and ill-cured, they reminded me, in
comparison to a lot of Costa Ricas close by,
of a heaped-up pile of natives who had died of
starvation in India and were awaiting crema-
tion, contrasted with the soldiers of one of the
Rajput regiments that came down into Udai-
pur to welcome the King and Queen when
as Prince and Princess of Wales they visited
India.

The following, therefore, subscribed to our
fund, and so enabled us first to offer a prize
of £50 for the best essay on the ‘‘ Fermenta-
tion of Cacao,” and then to engage such able
men as Mr. William Fawcett, B.Sc., F.L.S.,

Preface Xi.

formerly in charge of the Agricultural Depart-
ment, Jamaica, and Dr. J. Dekker, of the
Colonial Museum, Haarlem,! Holland, to read
through the essays and award the prize.
This they did, and agreed that it had
been won by the joint essay sent in by
Mr. Hudson and Dr. Nicholls (see pp. 153
et seg. in this book),

The subscription list, quite international in
character, includes the following names, and
I would like to state “right here” (to use an
Americanism) that it was Messrs. de Bussy’s
enthusiastic support .on the continent* that
brought in many of the firms. The Kolonial
Wirtschaftlichen Komitee also induced several
to subscribe. Here is the complete list :—

H. E. The Secretary of Agriculture, Cuba.

Messrs. Cadbury Bros., Ltd., England.

Messrs. J. S. Fry and Sons, Ltd., England.

Messrs. Rowntree and Co., Ltd., England.

Messrs. Wm. Porter and €o., England.

Messrs. Walter Baker and Co., Ltd., U.S.A.

Messrs. H. O. Wilbur and Sons, Inc.,
25 sh

Messrs. J. H. de Bussy, Holland,

Messrs. W. van den Berg, Holland.

Messrs. van Houten and Zoon, Holland.

De Indische Mercuur, Holland.

Der Tropenpflanzer, Germany.

Deutsche Kautschuck Ges., Germany.

1 Now amalgamated with the Vereeniging Kolonial
Institute at Amsterdam.

XiL The Fermentation of Cacao

Kako Einkaufs Ges., Germany.

The Sarotti Cocoa Manufacturing Co., Ltd.,
Germany.

Messrs. Suchard, S. A., Switzerland.

Agricultural Society of Dominica, B.W.I.

Arnold Gay, Esq., of ‘The Brothers”
Cacao Estate, Grenada, B,W.1.

Tropical Life, London,

Having secured such generous support, I
asked Mr. Fawcett if he would kindly translate
my crudely worded phrases, setting forth the
requirements and conditions of the competi-
tion, in a neatly worded: paragraph, which he
did thus -—

‘“The essay should record precisely and in
full detail the changes resulting from the pro-
cesses of fermentation and drying that take
place in the bean from maturity in the pod to
the time of putting the cured beans into bags
for market. Biological as well as chemical
changes should be noted. The action of
maximum, minimum and optimum tempera-
tures, and of checks producing differences of
times in the fermentation and drying processes
should be noted for every stage. The differ-
ences due to such variations on the resultant
cured bean should be clearly traced. The
possibility should be discussed of producing
at will by such variations, and independently
of the natural character of the bean, varieties
of taste and of colour, both internal and
external, so as to simulate the different kinds

Preface XUiL.

of cacao known on the market. Alterations
that might be made in ordinary methods so as
to improve the quality of the cacao should be
explained. Waste products should be con-
sidered, and their potential value indicated.”

Of the essays sent in for competition, only
the joint one by Mr. Geo. Hudson, of ‘“ Errard
Estate, St. Lucia (W.!.), and Dr, Luetus
Nicholls, attached, at the time, to the Govern-
ment service in that island, satisfactorily ful-
filled the terms of the competition so as to
render its publication of use and _ interest.
This essay, as will be noticed, is divided into
two chapters, say Chapter VI, by Mr. Hudson
(see p. 153), dealing with practical estate work,
and Chapter VII (p. 221), contributed by Dr.
Lucius Nicholls, containing the biological and
chemical part of the work.

In order to reach the subject intimately in
all its aspects, the authors felt that some such
collaboration between a scientist and a planter
was essential, and therefore sent in a joint
essay. Being awarded the £50 prize proves
their judgment to have been correct.

In declaring Mr. Hudson and Dr. Nicholls
to be deserving of receiving the £50, Mr.
Fawcett wrote as follows :—

‘ LoNnDON,
“ March 13, 1912.
“Dear Sir,—I have now gone through the
Essays on the Fermentation and Curing of

XIV. The Fermentation of Cacao

Cacao, and although J wish to consider them
in more detail before giving my final opinion,
1 think I may fairly congratulate you on
having obtained information that will be
valuable to the cacao planter, and still more so,
perhaps, to the local merchants, to whom the
unfermented cacao is brought by the peasants.
The investigations should also have the effect
of inducing such of the peasant growers, who
have not hitherto attempted curing, to carry it
out on scientific lines, which can be easily
explained to them by the agricultural
instructors.”

On March 29, 1912, Mr. Fawcett finally
wrote :— ;

“The Essay ‘A’ (Mr. Hudson’s and Dr.
Nicholls’) is in two parts, one being written
from the point of view of the planter dealing
with the details of the curing in a practical
manner. The second part is a successful
attempt to ascertain the causes which induce
the changes in the character of the cacao bean
during fermentation, and to put curing on a
scientific basis that has been tested and proved
to be satisfactory, instead of trusting to empiri-
cal methods.

“ A marked improvement of low-grade cacao
would be noticed in the markets, if due regard
were paid to the principles laid down. » This
would apply especially to the peasant pro-
prietors’ cacao cured by merchants, and also to
the cacaos cured by small settlérs themselves.

Preface

Mr. Wu. FAWCETT, B.Sc., F.L.S.

XV.

Xvi. The Fermentation of Cacao

Estates will benefit, too, in that the process
can be carried out with more certainty, and
therefore with less anxiety.

“The essay shows that the fermentation of
cacao is due to a definite organism, and that
the organism can be cultivated and used in a
pure state, excluding harmful organisms, and
capable of starting fermentation in cases of
difficulty.

«Proof i is offered of the change that’ takes
place in the ‘skin of the bean,’ so that it
becomes a good diffusion membrane, allowing
the ferment to pass through, but keeping
organisms out.

“‘The manner in which fresh cacao beans
become subject to fermentation is clearly
shown, also the scientific method of inoculation
which should be used. It is also demonstrated
that there are three stages in the -fermen-
tation process: (1) the fermentation proper;
(2) the stage when bacteria are most abundant
and acetic acid is formed, and (3) the putre- ~
faction stage. The author gives illustrations
of how these changes can be ascertained from
day to day, with directions for carrying on the
first stage as long as may be necessary. He’
explains the effects of different temperatures
on the various organisms and on the con-
stituents of the beans.

“There are also directions for making the
drainage from’ the fermenting vats or boxes
into a valuable by-product, viz., a good, pure
vinegar.

Preface XVil.

‘Altogether excellent work has been done,
and the publication of the whole essay, in-
cluding the practical details by the planter
(Mr. Geo. S. Hudson) would be most useful
to all who are interested in the curing of cacao.

(Signed) W. Fawcett.

“ March 29th, 1912.”

The report of Dr. Dekker (translated from
the Dutch—see De Jndische Mercuur of
May 7th, 1912, p. 406) read thus :—

“Messrs. J. H. de Bussy, who represent the
Netherlands contributors towards the fund, have
asked me to report upon the various essays
received. In my opinion Essay ‘A’ deserves
the prize. It consists of two parts written by
different authors. The first portion is appar-
ently by a man of practical experience, who
has looked closely into. the matter. He
describes ‘in detail the various methods used
in the preparation of cacao, on which his
information offers several hints. His remarks
on the claying and washing of cacao are very
interesting; he has, further, accurately ex-
amined the correct fermentation process, and.
noted the temperatures produced by it; and
also traced the influence that a culture of
yeast produces, according to Nicholls, during
the process of fermentation. This, he points
out, may bring about important improvements,
which, if carried into general use, would, in
his opinion, have great influence on the price

XViili. The Fermentation of Cacao

of cacao fermented by this method. With
respect to the drying, it was stated that besides
25 per cent. loss in weight by fermenting, a
further 39 per cent. was lost in drying, so ‘that
the cacao as shipped represents ‘but 36 per
cent. of the ‘green’ article as it comes from
the pod. It is in this portion. of the essay
that the author (Mr. Hudson) shows how
experienced and thoroughly at home he is
with his subject.

“The information given on the by-products,
vinegar and alcohol, is somewhat limited, but
at the same time. a good deal of information
is included that hitherto has not been’ made
known. No mention is made of putting the
pulp or pods to comimercial use, possibly
because the terms of the competition do not
ask for this.

“The second portion of the essay (that of
Dr. Nicholls)" disctsses the question of fermen-
tation from a scientific point of view. Here,
after certain preliminary information on the
chemistry of the subject, the author treats of
the réle played by different species of yeast in
the preparation of cacao.

“From his remarks it appears that certain
kinds or cultures of yeasts are produced which
live upon the sugar-containing portions of the
pulp of the fruit, and it is their presence that

: ‘The names-in each case were unknown either to

Dr. ‘Dekker or Mr. Fawcett. I only now include them
to simplify matters—[H. H. S.]

Preface XIX.

causes the increase in the temperature during
the process of fermentation, The author
obtained cultures of these, and discovered

Mr. J. DEKKER, PH.D.

or isolated one in particular, which he has
called Saccharomyces theobrome,' which micro-

1 It will be remembered, as Dr. Dekker points out,
that Dr. Axel Preyer, in rgo1, discovered Saccharomyces

XX. The Fermentation of Cacao

organism is met regularly on the cacao in the
sweating-boxes. In his description the author
avoids deciding (é2¢., is too sober in order to
decide) whether these organisms are a yeast
mixture or a single species. The discovery
that the yeast mixture cultivated from cacao
which has been fermented in the right way,
when transferred to new sweating-boxes or
to cacao that has been indifferently (22,
irregularly) fermented, improves the cacao
it is transferred to, is of great importance, for
the resultant cacao, cured with this ferment or
yeast, is decidedly of a higher market value.
This. fact alone is of such importance that I am
quite willing to overlook weaker portions of
the essay, such as including the results of a
chemical examination without giving the
analyses from which these conclusions are

theobvome, Preyer—in fermenting Ceylon cacao. The
name, therefore, had already been given to it. From
Dr. Preyer’s article in Dev Tropenpflanzer, of Berlin
(1g01), or the translation of this important treatise
published in Tvopical Life in 1909-1910, and now forming
the first essay or chapter in this book, it will be seen
that the influence of yeast in the fermenting of cacao
was discovered and noted over twelve years ago. It
was, in fact, through reading Dr. Preyer’s article that
the idea occurred to me of utilizing his invention ‘for
trying to secure a more even class of cacao from all or
any centre through the use of the culture that he
mentions., If uniformity is possible with rubber, why
should it not be with cacao? Dr. Preyer’s and Dr.
Nicholls’ information shows that it is possible. Having
started the. ball of research rolling, we must now hope
that others will take up the matter and carry it on to
practical and general use.

Preface XXi.

deduced, and on account of the very interesting
general information given, to declare that it is
worthy of the prize.”

Having thus explained in detail the causes
which brought the prize essay into being, and
through that, caused this book to be published,
I would like to add a few comments of my
own.

Both Dr. Dekker and Dr. Loew suggested
that the notes on the fermentation of coffee
should not be included, much less, therefore,
the notes on the fermentation of tobacco, which
I have published at the end of the book.
Whilst thanking them for the suggestion, how-
ever, I have asked to be excused from follow-
ing it, on the plea that I am most anxious to
call into being (for with many, if not with most
planters, the desire, as yet, does not exist) the
desire to seriously consider this question of
standardizing the system of fermenting, curing,
and generally preparing cacao and other pro-
duce for market; and having brought the
desire into being, to stimulate and spread it to
all planters irrespective of what they produce,
so long as the crop needs fermenting and
oxidizing to make it suitable for trade pur-
poses. It may be some little time before such
a book is again published, and therefore, as the
preparation of coffee, tea, tobacco, &c., is as
important as that of cacao, if not more so, as
the output and the capital required are larger,
I hope I may be excused when I try to kill

XXil. The Fermentation of Cacao

these several birds with one stone. Having
done so, I can only express the sincere hope.
that scientific and other experts will take up
the tale where my essayists have left off, and
carry it on until there is nothing more to be
said or learnt on the subject.

Meanwhile I would ask the readers of, these
essays to note where the authors agree and
where they differ, where at times, as they
themselves explain in the Last Word, their
views seem almost -directly opposed to one
another. This, however, I do not think is
altogether the case, for whether, as some
claim, the loosening and removal of the pulp
are the chief objects of the, various processes,
or if, as others claim, the advent of the air
and the oxygen it contains, to the produce,
is what should be mainly sought for, and
whether you oxidize or dry your cacao in the
final process (the air certainly cannot get in
the cells if the produce is wet and the cells
are full of moisture), the fact or facts remain,
that the pulp has to be loosened and got rid
of if you want to ship an attractive cacao,
and the oxidation has to be encouraged and
regulated if you want to export cacao of good
commercial quality. I would therefore ask
the readers to carefully note where and why
opinions agree and differ, as it is of interest
and importance for all to know the various
authors’ past and present views on the subject,
and to note where they are of the same opinion

Preface Xxill.

and when they find it necessary to criticize
each other. ‘‘When doctors disagree the
patient gets well.” J am, as just stated, not
at all certain that the doctors have disagreed
in this case, but if they have then all the
better, if the old saying goes for anything,
for then we shall know for certain that the
future health and prosperity of the plantation
cacao industry are assured.

In these days of rush and hustle, when
nature and civilization alike are supposed to
move to time and obey man’s wishes and
orders whether they are reasonable and possi-
ble or not, I would like to call attention to Dr.
Sack’s remarks on p. 151 regarding the dis-
advantage of rapid drying. Dr. Sack tells us:
“This experiment at the same time made it
quite clear why the old method, by which the
drying was done slowly, yielded a product
which far surpassed in quality the cacao, that
was rapidly dried, for with a slow process of
drying the reactions will continue for some
considerable time. With rapid drying they
will speedily cease.”

_ I have always maintained that produce can
be, and often is, dried far too quickly, but was
unable to explain why. Dr. Sack’s essay,
however, and the book generally, will, I think,
show that the mere evaporation of surplus
moisture is not the chief object sought after,
and that if you want to bring out and generally
develop the aroma and flavour of your beans,

XXIV. The Fermentation of Cacao

you must give them a reasonable time to
ferment and undergo the various changes
without which they can never become a
desirable article of commerce.

Mr. Hudson, it will be noted on pp. 153 e¢
seg., briefly touches on the question of by-pro-
ducts. To his remarks I would add that since
a spirit could also be produced, it might pay in
some cases to substitute this industry for that
of vinegar making. I do not say either would
pay, but -since there is an excellent demand
everywhere now for good vinegar, and petrol
or else denatured spirit, it is just as well to
discuss fully, once and for all, what we can
do with these present waste products of the
cacao estate, especially as in the aggregate
they tend to be a nuisance. There are several
kinds of spirits or oils used as fuel for internal
combustion engines, and the demand tends,
judging by complaints of high prices, to ex-
ceed the supply. In theory, therefore, there
is no reason why a well-organized cacao estate
should not produce its own spirit, if not its
own vegetable oil, as fuel for any power
required in the sweating or drying-houses,
or for tractors transporting the produce,

In face of such a theoretical possibility it
is well to note the following :—

If any further stimulus were needed to the
solution of the problem of bringing the pro-
duction and consumption of motor engine fuel
oil within more €mmensurate limits, the Mew

Preface XXV.

York Owl and Paint. Reporter told us a little
time back, it has undoubtedly been furnished
in the sharply advancing trend of crude
petroleum prices within the last few weeks.
The restriction upon the supply of gasoline for
the constantly growing requirements, while
keenly recognized during the last year or two,
has recently assumed a more serious aspect as
constituting a menace to the progress of the
industry. Almost every day brings some new
suggestion for relief, and the movement to
secure a more economical fuel for automobiles
has reached a national and international scope
through the initiative of the New York
Garage Association, the International Asso-
ciation of Automobile Clubs and the Society
of Automobile Engineers. The reported offer
of a sukstantial financial reward by the second-:
named organization for a substitute for gaso-
line is calculated to lend a quickening influence
to the mastery of the question. So far the
most practicable efforts in this direction have
been conceived in supplying a fuel in which
gasoline is used on a much reduced scale.
Kerosene was naturally bound to attract atten-
tion as the most adaptable agent, for produc-
tion of the latter was outstripping consumption
at a rate to make its outlet as an illuminant
an occasion for increasing concern, but what
may have appeared as the economical advan-
tages of this medium were a to a material
extent by the bothersome quéStions of starting

XXv1. The Fermentation of Cacao

the engine on such a comparatively heavy fuel
and of « overcoming the effects of the excess of
carbon, After several years of. steady applica-
tion a practical kerosene carburettor is said to
have been evolved, in which 70 per cent. kero-
sene to 30 per cent. gasolene is used, the fuels
being mixed in the same tank and readily
vaporising upon entering the combustion
chamber of the motor. Another method
which is said to have found approval is the
use of a vaporizer to heat kerosene to a point
where it volatilizes and then mixing the vapour
with air. —
At the same time the advocates of denatured
alcohol are exploiting its advantages as a
motor fuel with new zeal, as the market is
believed to be nearing a level’to bring it
into more practical competition with “the
petroleum product. While alcohol meets the
general fuel requirements, it cannot be adapted
to the prevailing type of motors, but with
motors designed especially for its use, greater
efficiency and almost 30 per cent. increased
power are claimed for alcohol over gasoline.
On a sufficiently extensive scale, fuel alcohol
may be produced about one-third cheaper than
gasoline on its present basis, but this realization
presupposes its adaptability to the automobile
engine. Its service in this field has already
been established as an inexpensive carbon
remover ; the larger use of lower grade g gasoline
has magnified engine troubles. by increased

Preface XXVIl.

carbon deposits, and a gill of denatured alcohol
poured into each cylinder has proved effective
in loosening the carbon so that it may be
readily blown out through the exhaust.

_ So speaks the New York trade paper ; going
East I noticed The Indian Trade Journal
told us in an article last January, in which it
also discussed the question of liquid fuel, that
‘Alcohol, although in many cases an excellent
fuel, is not commercially practicable in those
countries which impose a high excise duty
upon it, as in Great Britain, whereby its
price is rendered prohibitive. It is a vegetable
product, obtained by the fermentation and
distillation of grain, &c. It has a specific
gravity of ‘820, is moderately volatile, and
has a greater explosive range for variable
proportions of gas and air than petrol and air,
and can stand a much higher compression
without self-ignition taking place. Methylated
alcohol, or wood spirit, is the commercial
article mostly used in preparation of varnishes,
&c. French alcohol is purer and cheaper.
Wood naphtha is also sold as distinct from
mineral naphtha.”

On June 12 the same paper (/udzan Trade
JSournat) tells us India, as one of the largest
producers of vegetable substances suitable for
the manufacture of industrial alcohol, is keenly

‘1 Coco-nut planters, instead of losing the milk, as well
as those having manila and sisal fibre refuse, could also
make alcohol, so should note these particulars.

xxvii. The Fermentation of Cacao

interested in the continuous rise in the price of
petroleum spirits and in every fact that points
to the alternate substitution of alcohol as a
source of power. We therefore quote in full
an article from the Manchester Guardian which
furnishes a number of useful data :—

“There are many practical difficulties in
the way of producing a sufficient supply of
benzol under conditions which would allow
any attempt at price cutting on the part of the
suppliers of other motor fuels to be disregarded.
Alcohol is the only fuel which can be obtained
in virtually unlimited amount without encroach-
ing on capital, so to speak, as we have to do
with other fuels. It is obtainable from virtu-
ally everything in the vegetable world; not
only from roots, as beets and potatoes, and
from grains, but from such things as peat and
even sawdusts. There should be no difficulty,
therefore, in securing an adequate supply at a
low price. The sources from which it can be
obtained are so numerous and their interests so
competitive, that there would be no possibility
of an alcohol ring being formed to force up the
price of the fuel.

‘As regards denaturizing, when alcohol is
mixed with 25 per cent. its bulk of benzol, the
alcohol being of a specific gravity of 0°833, an
engine can be started up from cold and run
with an ordinary carburettor.. Benzol is often
employed as a denaturizing substance, especially
in Germany. It is stated that it is impossible

Preface XXIX.

to separate benzol or benzine from the alcohol
to obtain pure or dutiable spirit. In. just the
same way it is quite impossible to separate
wood spirit or methyl alcohol from the pure
spirit by redistilling, as, although the wood
spirit boils at a lower temperature, they both
distil over together. In England it is the
custom to add one-third of 1 per cent. of mineral
naphtha to the alcohol as a further precaution.
It would seem, therefore, that a use could be
found for as much benzol as could be produced
in denaturing alcohol and rendering it more
suitable for fuel. The supply of benzol would
be at least sufficient to cope with the demand
for the mixed fuel, and it could not be affected
in a price war, because the cheapness of
alcohol would be the determining factor, and
not the price of the comparatively small per-
centage of benzol. A mixture of pure 100 per
cent. alcohol with 912 per cent. of 90 per cent.
benzol gives the best results in practice.

‘The calorific value of alcohol is little more
than half the calorific value of petrol by weight,
but taking volumes into consideration the
difference is not so marked, because alcohol is
the heavier fuel. As will be mentioned later,
experiments have been made which have shown
that the thermal efficiency of a petrol engine is
not so high as that of one specially designed
for using alcohol, and that the net value*per
unit of volume is not far from the same with
both fuels. Alcohol, in fact, compares much

XXX. The Fermentation of Cacao

more favourably with petrol than is popularly
supposed. The fuel consumption of internal
combustion engines using alcohol is from 370
to 380 grm., or about 13 oz. to 13°5 oz. per
effective horse-power hour; and when using
alcohol of a calorific value of 6,000 calories
there is obtained a thermal efficiency of some
22 per cent. At one time alcohol was in
commercial use in Berlin for automobile work,
but by reason of its high price, compared with
that of petrol, its use was discontinued ; and in
Paris it has been used successfully with an
equal proportion of benzol for motor-buses.

“In internal combustion engines using alcohol
the explosive mixture can be compressed to
a much higher degree than can a mixture of
petrol vapour and air before self-ignition takes
place. When the alcohol is hydrated, the
compression can be carried still further, so that,
although the fuel is poorer, a larger percentage
of it can be converted into useful work. In
practice the compression is carried to 10 or 14
atmospheres, this high figure being made
possible by the water which is present in the
alcohol used. It is a ‘fact that alcohol when
slightly adulterated with water is a better fuel
than when pure. —

‘‘As to the properties of alcohol, from experi-
ments the heat value of alcohol appears to lie
between 13,310 and 11,664 B.t.u. per Ib., ‘the
latter value being the one most generally
accepted. One gallon of pure alcohol (specific

Preface XXXI.

gravity 0°79 at 59° F.) has a corresponding heat
value of 77,274 B.t.u. One pound of 100 per
cent. alcohol requires theoretically 9 lb. of air,
or 111°5 cubic feet,at 62° F., for complete com-
bustion. Care must be taken to see that the
right quantity of air is given, because if the
engine is run on an over-rich mixture acetic
acid is produced and causes corrosion of the
engine parts.

‘A series of tests have been carried out in
the United States with a view to determining
whether the petrol engines now in use could be
run on alcohol, and what improvements could
be effected in the design to render them more
suitable. In the trials eight engines ranging
from 2 to 40 h.p. were’used, three of them
being high-speed motor-car engines of which
two were of 4o h.p., the other engines being
of the internal combustion types such as are
used in commercial and agricultural operations.
Each of the eight engines was run on alcohol
as well as on paraffin and petrol, as many as
thirty distinct and separate tests being taken
on some of the engines. The alcohol used
was virtually the same as that obtainable in
this country under the name of methylated
spirit, and consisted of 90 per cent. of ethyl
alcohol and 10 per cent. of methyl alcohols
with about o’5 per cent. benzine added, the
percentages being in volume. Its _ specific
gravity was about 0°83. The petrol used had
a specific gravity of -o'71, which is to say that

XXXL. The Fermentation of Cacao

it was practically similar to the motor spirit
that can be bought to day in any garage in
England. The conclusions that were arrived
at from the tests were that any petrol engine
of modern type can be run on alcohol without
any material change in its construction, and
that the only difficulty would be that of starting
up from cold. For air-cooled automobile en-
gines alcohol was found to be specially suitable,
as the temperature of the cylinder can rise
much higher before pre-ignition takes place
than is the case when petrol is used. No tests
were made to determine the maximum possible
change in fuel consumption that could be
effected by causing the spark to occur at differ-
ent positions, but it-was found that an early
ignition was most suitable, and that the fuel
consumption was better at low than at high
speeds. When the initial compression was
increased from 75 |b. to 125 lb. per square inch
there was a slight but appreciable reduction in
the amount of fuel used. With any good
stationary engine it was found that a consump-
tion of 1°16 lb. of alcohol produced the same
power as a consumption of 0°70 |b. of petrol.”
In spite of the excise trouble elsewhere, no
doubt in the Tropics, although everyone.there
is not always a strict teetotaler, the spirit could
be rendered so unpalatable that it would be
impossible even for the owner of the most
hardened palate to drink it, while its use, if pur-
chasable at a cheap rate, would by supplying

Preface XXXIL.

cheaper fuel certainly go a long way to help
overcome the clamour one hears on all sides
for a cheap and reliable fuel, in order to
obtain better transport facilities. In face of
all this, when the reader comes to page 216
in Mr. Hudson’s essay, and sees that for every
bag of cacao produced we can look for two
gallons of vinegar and a corresponding supply
of alcohol, it is pleasant to think of the large
supples of alcohol that might be forthcoming.
from cacao estates, since, according to the
Hamburg Gordian, the world’ s output of raw
cacao is as follows :—

Tue Wor.p's Cacao Crops, AS PUBLISHED BY THE
Gordian, or HamsurG, 1n 1Ts IssuE No. 429,
FOR Marcu 6, 1913, P. 6040.

Tons of 1,000 kilos. 1910 IQII
Gold Coast ns wea 23,112 se 40,357
Ecuador ... ais oes 36,305 site 38,804
San Thomé sia 2 36,665 et 35,000
Brazil... ae i a 29,158 = 34,994.
Trinidad —. si os 26,231 iets 21,220
San Domingo ... aes 16,623 one 19,828
Venezuela if ae 17,251 is 17,381
Grenada ... od ee 5,846 is 5,948
Lagos... oe dan 2,978 aa 4,471
Cameroons and
German Dolenteat 41073 se 49404
Ceylon... a set 4,069 esa 3,064
Fernando Po ... 28 2,349 sek 3,000
Jamaica ... ve 1,743 oe 2,783
Dutch Colonies .. et 2,579 its 2,460
Surinam ... a 0% 2,043 tas 1,595
Haiti ain ste a 1,851 a 1,485

Carried forward 212,876 es 236,794

xxxiv. The Fermentation of Cacao

Tons of 1,000 kilos. 1910 I9QlI

Brought forward 212,876 we 236,794

French Colonies ane 1,575 we 1,364
Cuba ies sib 8 1,412 bes 1,251
St. Lucia i a 743 wits 940
Belgian Congo ... oo go2 sa 681
Dominica ou Set 573 Sos 576
Colombia win ae 297 a 400
Costa Rica oe ci 184. hg 343
Other centres... dias 1,000 a 1,500
Total we 279,562 .. 243,849

For last year, taking those centres of which
the actual figures have come to hand—and
this includes all the chief ones—and adding to
that the average of the others, the Gordian
gives us a total for 1912 of 230,000 tons,
so we can work out the following table :—

Total output, 1910 on 219,562 tons.
o » IQit ae 243,849 ,,
‘i » 1912 nf 230,000 ,,
693,411 ,,

This gives an annual average output for the
three years, 1910-12, of 231,137 tons (each
1,000 kilos) or 227,500 English tons. Taking
therefore Mr. Hudson’s figures of 2 gallons
of vinegar per bag of 200 lb. (see p. 216),

we have (227,500 tons = 509,600,000 Ib.)
5,096,000 gallons, valued at 2s, to 2s. 6d. per
gallon wholesale. Even at 2s., we thus have
over half a million sterling at present being
allowed to run to waste, and causing a nuisance
‘in most cases by doing so. If instead of

Preface XXXV.

vinegar it is found better to make alcohol,
then, following Mr. Hudson still, we are to
get 4 gallons of juice per bag of 200 Ib., or
twice the quantity discussed above, viz.,
10,192,000 gallons, at 3d. per gallon, giving
the planter 4£727,g00 a year without any
trouble and expense to obtain; whilst it will
probably save him both in getting rid of the
fluid in that way instead of his present one.

All this, I know, is on paper, but that is
the proper place for every calculation to begin
with; having thereby started the ball rolling
along the right channel, I leave it to the
readers of this book to see how far’ their
practice agrees with Mr. Fludson’s figures and
my theory.

I must not forget to thank M. Leplae, of
the Belgian Colonial Department at Brussels,
for the loan of the blocks out of their agri-
cultural bulletin, showing work in progress on
cacao estates in San Thomé. These will be
found on pp. 36, 86, 94, 96, 108, and else-
where, and their inclusion has added con-
siderable interest to the explanations of the
various processes and apparatuses described
throughout the book.

Since I started these notes, Mr. Fawcett
called my attention to a paragraph in the
Pharmaceutical fournat, of London, for
June 7, 1913 (p- 801), in which we are told
that—

“E, Perrot (in Comptes rend., 1913, 156,

xxxvi. The Fermentation of Cacao

1395) states that the method of getting rid
of the pulp from cacao beans by means of
alcoholic fermentation is detrimental “to the
quality of the beans, and furthermore, that
the changes that take place in the seed itself,
due to diastasic action, further reduces its
value. He suggests that the beans’ should be
treated with very dilute alkali, which renders
the pulp easily separable from the seeds.
Mechanical means, he urges, should be used
to separate the pulp from the seeds, and the
seeds should be at once sterilized by steam,
thus .arresting the diastasic action. After
drying, the beans would be unalterable and
of a definite character.”

On coming to p. 73 in this book the reader
will notice that Dr. Fickendey also discusses
the use of an alkali, in this case potash, for
treating the beans, since” “experiments led
to the discovery that the oxidation of tannic
substances increases. very quickly in weak
alkaline and neutral reaction.” Further, Dr.
Fickendey reminds us: ‘In some manu-
factories the cacao, after roasting, is treated
with potash.” On pp. 182-183 it will be seen
that Mr. Hudson discusses spraying the beans
with a cheap alkaline solution in the shape
of a lime wash.

More than one of the essayists strongly urge,
as I have always done, the necessity of the
Government—either the Imperial Government
at home, or the local authorities at the various

Preface XXXVIL

prodiicing centres—coming to the help of the
planters by carrying out experiments, of test-
ing new machines, supplying cultures, &c., that
will, if successful, benefit all, and which——until
proved to be satisfactory or not-—it is hardly
fair to an individual planter or maker to force
him, as at present, to risk losing his capital
so that all may benefit at the one man’s
expense. It certainly is not fair to any planter
to do so, and even with engineers the risk of
placing the right machines on the market before
putting them to the test in the Tropics is so
great that the introduction of labour-saving
appliances is being seriously discouraged
thereby—discouraged, too, when they are
badly needed. Personally, I consider all such
matters, once a number of reliable and prac-
tical men speak well of any new system or
machine, as well*as the establishment and
financing of an institution to scientifically train
planters, experts, plant-doctors, &c., must be
undertaken by the Home Government, since it
is mainly, if not entirely, for the benefit of the
folks at home, by insuring the output of the
raw material, food supplies, &c., that they re-
quire not only being maintained, but increased,
so as to keep pace with the rapidly increasing
requirements of the tax-collector and the wage-
earner, to say nothing of the mouths to be
fed on all sides. We are to-day at an epoch
of gigantic concerns and huge figures, as
exemplified by our 1913 Budget, in a time

xxxvill. The Fermentation of Cacao

of peace, standing at the enormous total of
4195,000,000. All this discourages individual
action by causing those wishing to help to
ask, ‘““What can I do against this or that
concern?” And unless the Government that
dominates, or should dominate, all trade con-
cerns points the way, individual members of
the rising generation will become still more
and more timid and averse to setting out on
those voyages of adventure that their fore-
bears undertook, and to which this country
owes its greatness, and without which our
prosperity, in comparison to that of other
countries, will not continue.

It is well to remember in connection with
this that an aggregate of individual efforts,
whether large or small, is far more ad vantage-
ous to any country or colony, as it brings in
its train greater anxiety for’ a settled state of
affairs, more local responsibility, and general
contentment, than is, as a rule, forthcoming,
when large labour-employing concerns are the
order of the day. In saying this I do not by
any means wish to decry the latter; they are
bound to be a most important factor in open-
ing up new lands; but at the ‘same time, when
we can secure the development of the Tropics
by the help of peasant proprietors, and big
privately-owned estates, I would urge that we
encourage and help them in every way possible.
This book offers one means of assisting such
folks, for it shows how the cacao or other

Preface XXXIX.

crops, produced by these innumerable large
and small landholders in varying degrees of
quality, can perhaps be standardized, and
offered for sale ‘‘ to type,” to the advantage
of everyone, and the small proprietor, perhaps,
most of all. If the authorities, therefore, wish
to attract and keep such people to the land as
owners, they must see to it that they do not
allow them to ‘lose their market” through
shipping an inferior and mixed, hence de-
fective, article. I would claim that the action
of the Governments in some of the tropical
colonies support me in this contention, since
they have, I understand, discouraged, if not
actually forbidden, company-promoting syndi-
cates from buying up small coco-nut estates
belonging to many independent owners and
forming them into one big company-controlled
concern. Apart from having a crowd of un-
employed, listless natives hanging about—for
they soon lose their purchase-money—I have
no doubt that the authorities feel that, both for
the natives themselves as well as for the
general trade and prosperity of the colony,
a thousand small garden settlements are pre-
ferable to ten big company-controlled areas ;
and if this is true with owners of a few acres,
who have but a few dollars at stake, it is trebly
true if we wish to draw capitalists from the
United Kingdom and the self-governing
colonies to take up their own lands and invest
capital in planting them up, that is, either

xl. The Fermentation of Cacao

money of their own or that which has been
entrusted to them personally, in the belief that it
will be utilized as carefully as if it were their own.

Organized systems and follow-the-man-from-
Cook’s routes must, owing to this, become the
order of the day, and the same as this noted
tourist agency so ably caters for our pleasures
and education, so must the Government of
this country recognize that, if they wish our
young men to go out to the Tropics to plant
and trade, they must not only train men to.
show them the way, but also interpreters and
guides to direct and show them how to proceed
from the time they arrive. Arrangements, in
fact, must be made whereby the boy whilst
still at school (or his father who wishes to train
him for his future career) can see his way quite
clear ahead, to first study agriculture and agri-
cultural chemistry, &c., on this side, and then
go to an agricultural college in the Tropics (to
be, I hope, soon established) for one, two, or
three years, to specialize in tropical agriculture,
plant diseases, and the preparation of the crops.
Given these encouragements and facilities, a
large number of young men would, I am sure,
go to the Tropics to extend our trade in many
ways, and increase our supplies of raw material
and foodstuffs at home. They would, in a
word, go where they were wanted, and not
remain here to increase, the struggle for exist-
ence and for profitable investments in these
Islands. No local centre can do this; it

Preface xli.

would not be fair to ask them to do so, since
the training is but part of the huge co-
operative scheme in force at home whereby
the wealthy educate and insure the poor, and
keep them from want when out of work; only
in this case it is the sons of the capitalist
class that we want to catch—not for their own
benefit, but to train them to supply the
masses here with raw materials for the fac-
tories and food for the home. Under such
circumstances, therefore, who but the Imperial
Government at home—that is, the representa-
tives of those for whose benefit the scheme
is being formulated—should finance such in-
stitutions ?

Coming to where reference is made in this
book as to the necessity of the Government,
either at home or in the Tropics, helping those
who are trying to solve the difficulties of agri- ,
culture in the Tropics, and the production of
crops thereby, I would like my readers to
notice the footnote on p. 47, where we are told
by no less an authority than Zhe [udzan Plan-
ters’ Gazette, of Calcutta, that ‘ much uncer-
tainty is attached to practically every branch
of tea manufacture. It is surprising that a
scientific department was not created many
years ago. If such had been the case we
should probably now be * groping in the dark’
to a much less extent than we are.” This
refers to the cultivation of tea, but it could
equally well be applied to cacao, coffee, tobacco,

xlii. The Fermentation of Cacao

&c., and even to rubber, although with that
product a mass of information has been issued
of late years. But, with rubber also, the out-
put of such data has been a spasmodic, hap-
hazard and uncertain, often unexpected one,
not an organized campaign carried out as part
of a systematic series of researches at the
instigation of the Home Government, whose
revenues through. the increased prosperity of
its subjects, shareholders, engineers, rubber-
manufacturers, workpeople, and allied trades
have benefited enormously, owing to - those
concerned being able to pay such heavy contri-
butions at home and abroad into the Imperial
exchequer.

“Such trades as those in which the material
used has to be fermented,” Dr. Schulte tells
us on p. 115, “require special scientific insti-
tutes to which the manufacturer can turn at
any time for advice when unexpected results
or irregularities occur in their work. Unfor-
tunately, as regards the treatment of cacao
such an establishment is, at present, practically
non-existent. ° . . What should be done
is to introduce the process (likely to be of use)
on one plantation in each colony, a scientific
expert specially trained to the work being
engaged to assist, and only when these two,
the scientist and the planter, together have
thoroughly mastered the process, to then in-
troduce it generally to the other estates. In
order that advice might be at hand when

Preface xiii.

required, an expert, as described above, should
be permanently appointed to, and reside in
the colony, with a suitably equipped scientific
institute placed at his disposal, in which further
investigations and experiments could be carried
out and checked.”

Dr. Schulte is quite right, and perhaps up to
a certain point it can be claimed that such work
can be carried out in some of our colonies, but
not sufficiently to give confidence to those who
wish to see an assured success in view before
they send out their sons to take up planting,
or entrust their capital to ventures run by
other people’s sons. Such investigations once
started and discussed as those reported in the
forthcoming pages must satisfy no one, they
are only intended to point the way to further
research, but that way is, I fear, too intricate
and costly for individual action to carry
out all such investigations to their uttermost
point of finality. To do that we need a centre
or centres of learning which will stand in
relation to the plant world on the same lofty
plane that hospitals do with human beings,
that is to say we need agricultural colleges in
the Tropics to train plant-doctors and experts
overseas, as we have long had to train physi-
cians and doctors over here.

As things now are, whilst the public get the
benefit of cheaper tea, &c., and the Exchequer
scoops in its millions of revenue therefrom, the
planter is left alone to discover how he can

xliv. The Fermentation of Cacao

still turn out the tea as cheap, or still more
cheaply, in the future, in spite of the higher
wages, increased freights, and heavier expenses
that are menacing him on all sides. Truly the
British public is neither grateful nor wise;
because a few men stake their all to feed
them cheaply, and will go to the wall if
adverse circumstances cause luck to go against
them and stop the work, is it right, either
morally or economically, to take no interest
in such people? Would it not be a wiser policy
to encourage them to further action by training
them scientifically to the highest standard to
fight our commercial battles as we do the
officers of H.M. Services to fight for us.
internationally ; and in this training should we
not show them how to handle the machines
they will be called upon to use, and train them
to learn which to reject as unpractical and
unprofitable, and which to adopt as being
likely to save them time, labour and money ?
I feel sure that we should, and so do many
others. Thank goodness there is no longer
lacking that first glint of light that makes one
believe the sunrise of realization is about to.
dawn upon the public, and so enable them
also to share our opinion! I devoutly hope
they will. And now to get back to our subject,
viz., ‘‘ The Fermentation of Cacao.”

H. Hamer Smiru.
London, August 1, 1913.

SYNOPSIS.

FOREWORD BY SIR GEORGE WaTT
PREFACE BY THE EDITOR ...

Details of the essays included and fhets arent
subscribers to the 7ropical Life Prize Fund which
caused the book to be written—the report of Mr.
Wm. Fawcett (formerly Director of Plantations,.
Jamaica, B.W.I.), and Dr. Dekker on the Prize
Essay—Why notes on the fermentation of Coffee,
Tobacco, &c., were included-—the opinions of the
various essayists discussed—the question of by-
products and their use as liquid fuel—7he New
York Oil and Paint Reporter on the need of
increased supplies—TZhe Indian Trade Journal
on the same matter—Z7he Manchester Guardian
discusses the need of increased supplies of alcohol
and its calorific value—can petrol engines be run
on alcohol?—it is agreed that they can be—table
showing the world’s production of cacao—what
that would yield in vinegar or alcohol—M. Leplae’s
blocks—Zhe Pharmaceutical Journal (London) on
Perrot’s notes regarding cacao fermentation—Dr.
Fickendey and Mr. Hudson on treating the beans
with alkalis—the need of Government help on a
more extended basis—especially to test machinery
for the benefit of all—the need to insure the output
of large supplies of raw material and food supplies
—how to encourage the flow of young men and
capital to produce these—what the /zdian Planters’
Gazette says on the subject regarding tea-planting
—the present short-sighted public and its policy—
Dr. Schulte’s plea and suggestions—train doctors
for plants as we now do for people—the public and
cheap tea—the Exchequer and the tea tax—both
neglect the producer—train men to use labour-
saving machines as you do munitions of war.

CHAPTER I.—DR. AXEL PREVER.

Is it necessary to ferment cacao 3h dante: of
washing—How fermentation was effected in 1775

xlvi. The Fermentation of Cacao

PAGE
-—a Venezuelan method—the Strickland process—
Semler on fermentation—Friederici on fermenting
—how it is done in Surinam—a Ceylon method as
practised on Gangaroowa Estate, near Perddeniya
—other methods—washing cacao—Chittenden’s
ideas—table showing results of various methods—
Aublet—Chittenden—Morris—Strickland—Semler
Friederici— Preuss—Preyer —Saccharomyces cere-
visie— Preyer’s fermentation experiments in Cey-
lon fully described —Do enzymes cause the changes?
—the work of the living yeast cells—.S. ellipsozdeus
—S. membranefaciens—Preyer’s ferment S. cheo-
brome (Preyer)—a full description of it and the
nature of its fermentation—Chittenden’s experi-
ments—the question of chemical combinations—
the action and activity of bacteria—S. ¢heobrome
—the best ferment—superior cacao defined—the
results of lack of inoculation—the question of tem-
peratures—a table of experiment results showing
advantages of inoculation—the disposal of the
vinegar or fluid—the duration of the entire
fermentation period—a recapitulation of the fore-
going—a fermenting tank described and illustrated.

CHAPTER II.—DR. OSCAR LOEW. eee 32

The purpose and necessity of fer mentation adiubaute
—Sir George Watt describes the preparation of
cacao in India—Safford describes it in the island
of Guam (belonging to U.S.A.)—Hinchley Hart
has a word to say also—the changes brought about
by fermentation have been studied by Prof. Harri-
son in British Guiana—an enzyme the cause—the
Professor tells us exactly what the process consists
of—further and finally he gives more useful details
—how fermentation is carried out—the temperature
discussed—the contents of a pod described and
illustrated—its structure explained--the effect of
the fermentation on the beans—the results of that
effect—Eugene Lange says fermenting does not
pay—but what happens when it is not done—coffee
fermentation compared—the fine colour of cacao
due to fermentation—the oxidizing enzyme experi-
mented with—colour change in cacao compared to
that in black tea—the change of colour in tea dis-
cussed—further investigations regarding the pre-

Synopsis xlvii.

PAGE
paration of tea asked for—the oxidation of the
persimmon fruit—cacao red does not cause the
colour—detailed analysis of Calabacillo cacao—the
chemical changes that take place in the beans—
the change of flavour—how to prove the presence
of oxidizing enzymes—the slime tissue of coffee and
cacao compared—Prof. Harrison on the decrease
of tannin in cacao—enzymes needed to ferment
cacao and coffee alike--the production of the
aroma in cacao—fermentation seems to have
nothing to do with it—only beans acted on by
enzymes can produce the true aroma—cacao butter
is not indigestible—at least not more so than cow’s
butter—a summary of the foregoing—the chiet
object of fermentation according to Loew.

The Fermentation of Coffee.— Its definition—the
anatomical structure of the fruit discussed and
illustrated—the preparation of coffee for market
described—coffee terms—the fermentation process
—analysis of the dried pulp—is it good as a
manure?—the cacao ferments discussed-—coffee
fermentation temperature—why fermentation is
essential—how long to ferment—why one avoids
too prolonged a period—the drying of coffee—Dr.
Loew reviews his previous remarks.

CHAPTER IIJ].—DR. FICKENDEY ... ae aia .. = 66

The preparation of green cacao—the two processes—
the fermentation of the pulp—and the processes
affecting the bean itself—what enzymes are—in
preparing cacao the chief aim is to kill the germ—
fermentation is not essential for this—how other
means can do as well—access of air turns the
beans brown—what causes the bitter taste in the
beans—what brings about the change in colour—
another way to remove the bitter taste—Criollo
beans behave differently to Forastero—weak alka-
line solutions hasten oxidation—the maximum
temperature—advantages of using a potash solu-
tion—the need of further investigations—how these
could be carried out.

CHAPTER IV.—Dr. SCHULTE IM HOFE... wis bal YO:

Technical terms discussed—why’ Dr. Schulte becam
interested in fermenting tropical produce—Cacao

xlviii. The Fermentation of Cacao

fermentation in ‘the Cameroons—the chemical
changes in cacao are similar to those in black
tea—tea fermentation described—the oxidation of
tea—the main object of rolling tea—the processes
with cacao compared—how to secure uniform fer-
mentation—the change in colour in the beans—
what constitutes cacao fermentation—the process,
as generally understood, not absolutely essential—
oxidation of cacao and tea compared—beware of
over-acidification— drawbacks of over-rapid drying
—why sun-drying was considered to be best—
self-heating more favourable to oxidation—why
mechanical dryers are necessary — slow-dirying
favours oxidation — higher temperatures helps
oxidation both in tea and cacao — oxidation
experiments at Victoria, Cameroons — oxidation
an essential point in cacao fermentation —fer-
mentation experiments carried out in Germany—
serments discovered on imported beans—higher
temperatures accelerate oxidation—the moisture
content—small water content means slow oxida-
tion—is 15 per cent. the optimum amount of
water ?—factory experiments v. laboratory work—
20 per cent. moisture caused moulds to form—
what Dr. Schulte proved by his experiments—the
question of optimum temperatures for oxidation—
fermentation experiments in San Thomé—a des-
cription of the oxidation chambers erected—how
the fermentation was carried out—changing the
beans assists the process—trolleys of trays and
chamber drying made use of—shall the beans
have 15 or 20 per cent. of moisture ?—how to detect
excess of moisture—the change of colour and how
long it takes—testing for flavour—how it is done
with tea—when to check oxidation—oxidation
depends on temperature—the optimum tempera-
ture—period of fermentation on Boa Entrada—the
essential processes of fermentation, viz., the sugar
converted into alcohol, and the alcohol into acetic
acid—why oxidation is necessary—cacao oxidized
at high temperatures turns out best—gathering the
cacao—fermenting—“ unripe” beans an incorrect
tern) — methods in the Cameroons —in San
Thomé—when to stop fermentation—the simplest,
cheapest, and most certain method—fermenting
saccharine juice can start the process on non-

Synopsis : xlix.

PAGE
fermenting beans—a pure yeast culture has no
influence on the quality of the cacao—fermentation
floors—avoid cement—washing v. non- washing
in the Cameroons — drying the cacao — various
methods discussed—in Cameroons—in Trinidad—
in San Thomé—in Fernando Po—Count Spengler’s
type of dryer—Dr. Schulte’s idea—the oxidation
of cacao—the need of scientific institutes—for
cacao these are still lacking—test results well
before being satisfied—try on one estate and when
proved use on others—the need of experts to
supervise and advise-—drying in Samoa, and Ceylon
—the result of over-acidification—the need of
flavour in cacao as in tea—ferment and oxidize
too little rather than too much—the question of
moisture content—how to test the degree of
moisture—when the drying is complete—an oxi-
dation house described—how it is utilized—its
capacity per 500 kilos of cacao—tunnel drying—
tasting the cacao the same as with tea—tasting
samples and how to prepare them—how it was
done in San Thomé—the preparation for shipping
—marking—packing—sampling—the variations in
qualities—the forwarding of samples—note what
suits.

The Fermentation of Coffee.—Compared with cacao—
the action of oxygen—the temperature—beware
of acids—mechanical contrivances—what fermen-
tation facilitates—what acids may do—a San
Thomé method of preparation—the process on
Boa‘Entrada—how a good result can be obtained
—what over-acidification causes.

The Fermentation of Tobacco—Is too much impor-
tance placed: on ferments?—the reasons of the
processes—the cause of heat in tobacco heaps—
over-moisture causes acidification—how to avoid
same—how good tobacco is obtained—Dr. Schulte’s
experiment—the result declared to be good—with
tobacco, fermentation only a subsidiary part—what
constitutes the essential principle of tobacco. fer-
mentation—the fermentation of various products
‘discussed and compared.

CHAPTER V.—Dr. J. SACK... tee ws oe see 134
Fermentation methods scarcely changed since 1773 ,

a

1. The Fermentation of Cacao

PAGE

—how it was carried out formerly—peculiar old-
time notions—sweating or fermenting boxes, their
make and.uses—the period of fermentation—too
little known of the changes of the beans—there
must be others that should be investigated—results
of a few experiments—Is the fermentation due to
a chemical or biological process ?—how to prove it
is a biological process—the proof that air is neces-
sary-—also that the conversion of the sugar content
causes an increased temperature—what happens
when the rain washes the sugar off the’ outside of
the beans—-external and internal fermentation—the
phases of external fermentation summarized—
formula of the oxidation process causing alcoholic
acidification—oxygen: a necessity—the décomposi-
tion of alcohol into acetic acid develops heat—in-
ternal fermentation discussed—what kills the beans
—tests to prove the exact temperature that kills
them—change of colour in the seed—air necessary
to produce brown colouration—definition of an
enzyme—enzymes harmless at roo° C. and most
active between 45° and 60° C.—nothing known of the
chemical composition of enzymes—tests to prove
that enzymes bring about the change of colour—
beans die at about 45° C.—the enzyme at about
70° C.—definition of a glucoside—the formula of
cacaonine—composition of a molecule of theobro-
mine—formula of the enzymitic division of cacao-
nine—theobromine an irritant—cacao-red odourless
‘and tasteless—the aroma of cacao developed with
fermentation—why, when driéd slowly, a fuller
aroma is obtained—Dr. Sack sums up—and con-
cludes with discussing the loss incurred by washing
cacao.

CHAPTER VI.—By Mr. GEORGE S. HUDSON ... we 153

_ (Being Part I of the Joint Prize Essay.)

Scope of suggested improvements —Forastero, Criollo,
Pentagona, Calabacillo, Amelonado types dis-
cussed—careful treatment may enhance values—
the inoculation method of fermentation to help—a
table of values on June Ist, 1913—qualities and
values discussed—Does it pay to turn out better
cacao? Mr. Hudson says “ Yes !”—present imperfect
systems discussed—the “ Cacao-fly” and ‘its work
—Dr. Lucius Nicholls’s inoculation process to im-

Synopsis

prove matters—chemists to sell the medium—the
Government should co-operate—£300 extra profit
per 1,000 bags to result—Is unfermented cacao
asked for ?—care needed to inoculate suiccessfully—
“ weathered ” cacao— sweating boxes — vacuum
dryers to revolutionize drying—the small producer
—picking unripe pods—* unripeness” a misnomer
—remove the placenta and refuse—separate the
qualities—capacity measurements of wet cacao—
how to calculate same and check loss in weight—
four baskets equal one barrel weighing 300 1b.—
ratio of uncured to cured cacao—full details as to
weights and loss in curing—Is fermentation profit-
able ?—fermenting receptacles or sweating-boxes
discussed—7 barrels or 2,100 Ib. wet cacao in a box
—the need to make them strong—materials for
making boxes discussed—what to avoid and what
to choose—plan of an ideal curing house (illustrated)
—slate sweating-boxes—fermenting cacao, tem-
perature, ferments, changing, &c., &c. discussed
—a week’s ‘work detailed—beware of 100° F.—
keep your boxes clean—maintain perfect drainage
—how to secure this—arrange your leaf-cover care-
fully—what happens when you do otherwise—most
suitable leaves to use—how to assist stubborn fer-
mentation — give. “‘ cacao-flies ” free access —the
importance of ‘changing ”—immediate result of
slackness in this—use a wooden spade—some
negative experiments—a table of fermentation tem-
peratures -— again regarding the distribution of
inoculating cultures—drying by natural and arti-
ficial means — sun-drying — boucans — covered-in
areas—trays, trolleys, and floors—areas, say 5 sq.
feet per cwt. of dry cacao—might be reduced to
3 sq. feet—the palette—sun-drying discussed in
detail—artificial dryers—Whitfield-Smith’s design
(illustrated) and Mr. Hudson’s improvements (illus-
trated)—rotary dryers — Messrs. John Gordon’s
make—the Hamel Smith dryer—the difficulty of in-
teresting planters—vacuum dryers—Messrs. George
Scott’s described—the Passburg vacuum dryer—if
more expensive still worth the money—the Govern-
ment stations should test machines for the informa-
tion of the planters—washing cacao—the loss in
weight and gain in price—washing v. claying or
polishing—‘ airing” washed cacao --clayed cacao—

lit. The Fermentation of Cacao

: PAGE
clay no longer a hall-mark of good quality—polish-
ing or “ dancing”’—how it is done and the cost—
the process should be done away with—machine
polishers—the Malins-Smith machine—Barnard’s
polisher—their use may save money and give a
better quality—bagging for export—cost, weights,
and strength — by-products — vinegar — possibly
200 gals. per 100 bags—to sell 2s. or 2s. 6d. gal.—
how to prepare it—cacao alcohol—Pard and its
cacao wine—cacao jelly.

CHAPTER VII.—By Dr. Lucius NICHOLLS... wi 227
(Being Part II of the Joint Prize Essay.)

Fermentation defined—Pasteur’s discoveries — the
cause of sweating or fermenting in cacao—the re-
production of yeasts and ferments—the different
varieties—Saccharomyces theobrome—its isolation
and cultivation—yeasts in sweating-box scrapings
—the “cacao fly” (Drosophila melanogaster) (illus-
trated) and its work—experiments to prove the
utility of the flies—the chemistry of the cacao-bean
—analyses of their composition—the acetic acid
and alcohol present—what the sweating of cacao
really is—physical changes brought about hy fer-
mentation—the losses and gains from fermenting—
melting-point of oleuzm theobrome—the effects of
dancing on the fats in the beans—Dr. Nicholls dis-
cusses glucose—sucrose —starch — theobromine—
theine — cacao red — albumen — fibrin — gluten—
bitter principle—salts—acetic acid—alcohol and
acetic ether—summary of the changes which take
place—the isolation and cultivation of the organ-
isms which ferment cacao—a medium upon which
the fermentation organisms will flourish—how to
breed bacteria and yeasts—the isolation of organ-
isms in pure culture—a discussion on yeasts (illus-
trated)—new sweating-boxes need inoculating —the
blackening of the beans—how to prolong fermenta-
tion-—how to obtain a yeast culture in bulk—the
application of the solution—the question of tem-
peratures—yeasts killed at 133° F. and dormant at
120° F.— optimum temperature for the cacao
between 110° to 120° F.—but flourish best below
110° F.—a uniform temperature means a uniform
Sweating with yeast cultures—cacao juice—the

Synopsis lit.
PAGE
nature of the fluid —vinegar. easier to prepare
than alcohol—experiments for vinegar making—
cacao vinegar compared with others—a table of
comparisons.

CHAPTER VIII.—THE LasT WorbD, by the Editor ... 252

Dr. Fickendey’s views in March, 1913—he discusses
the composition of the juice—also methods of fer-
mentation—he is not keen on pure yeast cultures—
his views on the main object of fermenting cacao—
but essential changes can take place without fermen-
tation—how this can be done by: (1) mechanical
Means; (2) chemical means ; (3) change of tem-
perature—devitalization by cold—beans so treated
said to be best of all—the Imperial Institute on
West African cacao experiments—methods of pre-
parations and resulting values—the question of
colouration and loss of bitterness—the part played
by oxidases—the brown-colouration discussed—the
behaviour of beans with white nibs—washing and
drying—the Cameroons no longer washes the
cacao—sun-drying best but not always possible—
fans a help in equalizing heat in drying-houses—
Does it pay to improve the quality of cacao?—Dr.
Fickendey discusses Dr. Preyer’s essay and the
‘fine work” of Loew—also Dr. Schulte im Hofe’s
process—he thinks Nicholls and Hudson’s essay
useful—Nicholls’s discovery ve the utility of the
cacao-fly is important—Dr. Schulte im Hofe agrees
with Fickendey rather than Preyer and Nicholls—
Dr. Loew on Hudson’s and Nicholls’s essays—the
development of the aroma--the question of the
Saccharomyces yeasts and which is best—Dr.
Nicholls criticizes Dr. Schulte’s essay—Dr. Axel
Preyer’s “last word”—he considers little or no
advance has been made since he wrote his essay in
1900—the whole matter must be followed up—will
the yeasts used in one centre thrive elsewhere ?—
we must all continue the investigations—the need
of standardization and bulked shipments—the Ag7t-
cultural News on the fermentation of cacao—the
question of temperatures—Bainbridge and Davies
(of Messrs. Rowntree and Co., Ltd.) on the chemical
changes and the yeasts—definition of the aromatic
principle of cacao—how to detect adulterants in
cacao butter.

liv. The Fermentation of Cacao

PAGE
CHAPTER IX.—A FEW NOTES-ON THE CURING AND
FERMENTING OF TOBACCO, by the Editor wee 285

The views of Mr. J. N. Harper of South Carolina—
different processes and different tobaccos—fermen-
tation in tobacco also due to enzymes—enzymes

_destroyed above 152° F.—fermentation takes place
more rapidly at a high temperature—bright yellow

.and dark-tobaccos-—Mr. Charles R. Jones of the
Philippines and his views—the tobacco or cigarette
beetle (Lastoderma serricorne)—open mandalas or

_ heaps encourage them—what the beetles cost the
planters—to evade the beetle new methods of fer-
mentation may be necessary—Mr. Jones suggests
how this may be done and leave a profit—Mr. N. C.
Chudhury, of India, tells us about drying and fer-
menting in Behar—the optimum temperature for
drying cigarette tobacco—other temperatures for
cigar tobacco—how to secure and maintain these—
Mr. Bernard Coventry (India) considers primitive
methods handicap tobacco-growing— why this
section was included by the Editor.

ILLUSTRATIONS.

PAGE
A Prolific Cacao Tree in Para, Brazil sits Frontispiece
Dr. Axel Preyer 3
Cacao Shading Coffee, ‘Guadeloupe... 4
Cacao Tree in Bearing, Trinidad 8
Pulp of Fresh Forastero Cacao Beans from ‘Ceylon 18
The Shell of a Ripe Cacao Bean, Forastero vanes, from
Ceylon sles me oe)
Cacao Yeast (Saccharomyces ‘theobrom@) 22
Section of Tank for Cacao Sweating 30
Dr, Oscar Loew : 33
Cacao in the Fermenting or Sweating Boxes (San Thomé) 36
Structure of Cacao Fruit 3 a8 £6 ee 38
Structure of Coffee Fruit 59
Dr. Fickendey .. : 69
Dr. Schulte im Hofe . oo 79
Drying Cacao in Trays on "Wheels at Agua Tze (San
Thomé) .. 86
The Buildings ona ‘a Large Cacao Estate, Boa Entrada, San
Thomé 94
Cars of Cacao, covered with ‘Banana Leaves, arriving ‘at
the Fermenting or Sweating House (San Thomé) 96
Drying Cacao on ae on Boa Entrada Estate, San
Thomé ... 108
Cemented Boucans or “Drying ‘Areas in San Thomé, with
Cacao Beans apes out to dry 110
r. J. Sack se ste 135
Ma George S. Hudson | : 155
Plan of Mr. Hudson’s Ideal Cacao-c curing House... 174
The Palette... 192
Plan of the “ Whitfield ‘Smith » Hot-a -air Dryer see 196
Mr. Hudson’s Modification of the “ Whitfield Smith ”
Hot-air Dryer ... re 197
Dr. Lucius Nicholls 223
Smear from Cacao showing Involuting Yeasts ine 224
The Cacao-fly (Drosophila melanogaster), its Eggs and
Larva 227
Cacao Seed showing the Convolutions of its Cotyledons 233
Sloped Agar Hue = Suewin Yeast Gomis on the eloped
Surface ... 240
Yeast Smears ... 242
Three forms of Acetic Kad forming ‘Bacteria 243
The Cacao-fly (Drosophila melanogaster) . ; 272
Open Mandalas (Fermenting Heaps) of Tobacco. 288

Closed Mandalas with Tobacco

ERRATA.

P. 25, line 12, for ‘‘p. 29” read ‘‘ p. 27.”
P. 53, line 23, for ‘‘p. 36” read ‘* p. 35.”

P, 233, under illustration, for ‘‘ convolution ”’ read “‘ convolutions.
P. 249, line 11, for ‘* 600 gallons’’ vead ‘‘ 4oo gallons.”

”

THE FERMENTATION OF CACAO.

CHAPTER I.
By Dr. AXEL PREYER.

Is it absolutely necessary to ferment freshly
gathered cacao seeds or beans? This query
has already been repeatedly raised and dis-
cussed. However, the answer from the plan-
ter’s point of view is given in the: difference
in the price between the fermented and
unfermented cacao. With Ceylon cacao this
difference is so great that, as far as I know,
no European out there sends unfermented
cacao to market. The unimportant quantities
produced by natives are for the most part
consumed at home.

The bitter substances in cacao seeds give
them an unpleasant taste, and this can only
be removed by fermentation. Furthermore,
the fermentation influences the aroma of the
product to a large extent, as well as the colour
of the bean, shell and inside contents (cotyle-
dons), each and all of which are important in
determining the price.

Finally, the pulp surrounding each seed is
loosened to such an extent that in the washing

I

2 The Fermentation of Cacao

process which follows it is removed. Washing
the beans enables them to be dried quickly
and uniformly, consequently there is no doubt
that it is necessary to ferment cacao; but
wide differences of opinion still prevail as to
which are the best methods to be employed
to do so.

The excellent quality of Ceylon cacao
seemed to justify an examination of the fer-
mentation process as carried on there, and
after a series of practical tests on both a large
and small scale, I have hit upon practical
results. For the detailed statements of these
results I wish here to express my hearty thanks
to Dr. J.. C. Willis, Director of the Royal
Botanic Gardens in Ceylon, for his very: kind
help.’

For practical purposes it is customary to
employ many ways to ferment cacao; these,
however, are similar in ‘several points. Some
of the methods of preparation in use in the
West Indies are mentioned in Hinchley Hart's
“Cacao,” published in 1892.

Aublet said in his work, “ Plants of Guiana’
(1775), concerning the fermentation of Teo-
broma guranensis: ‘‘The beans taken from
the broken fruit were put with the pulp in a
vessel ; this substance after about twenty-four
hours’ fermentation became liquid and wine-

,

1 Since the above was written, Dr. Willis has left
Ceylon and taken charge of the important Botanical
Gardens at Rio, Brazil.—H. H. S.

Dr. Axel Preyer

ies)

Dr. AXEL PREYER.

4

The Fermentation of Cacao

Cacao SHADING COFFEE, GUADELOUPE.

Dr. Axel Preyer 5

like; the beans were left in until the shell
became brown, and one was certain that
the germ had been killed. The quality of
the cacao depends on the degree of ripeness
of the fruit and the length of, time that the
beans are fermented; beans, when ripe and
fermented, separate themselves easily from
the surrounding: substance and soon dry; the
wine-like liquid is slightly sour and drinkable ;
distilled it becomes a sharp spirit, which is
inflammable and of pleasant taste.”

Sir William Robinson reports on a method
tried in Venezuela. The Conuquero dries his
beans by exposing them in the sun for some
five or six hours, after which they are fer-
mented until the following day, and again
exposed for five or six hours in the sun, and
so on. Another method, used by the small
planters, is to ferment the cacao beans during
the evening whilst still warm from the
sunning.

Mr. Strickland! recommends the following
‘process: Three stone tanks to be. built and
cemented, each 11 ft. (3°35 m.) long, 7 ft.
(2°13 m, ) broad, and 5 ft. (1°53 m.) deep ; high
above these a corrugated iron roof is placed,
and below a drain made for the liquid. The
broken cacao (ze, the contents as taken
from the pod) remains in the first tank five

1 Of Trinidad. The originator of the well-known"
Strickland process of fermentation.—H. H. S.

6 The Fermentation of Cacao

days, and is only covered with banana leaves,’
the air being supplied through five’ per-
pendicular? bamboos (made into tubes by
breaking through the joints), with numerous
holes in their*sides; these bamboos can be
closed at the ends as desired, either partly
or altogether, by clay stoppers. Closing them
soon produces a pleasant vinous odour, and
the fermentation takes place.

The cacao is then removed to the second
tank, when an acid reaction at a lower
temperature takes place; after remaining for
five days the cacao is transferred to the third
tank, in which it is left for the same length of
time. The pleasant smell then disappears,
and, if attention is lacking, decompusition of
the beans easily sets in, whilst injurious gases
are formed and beans become discoloured.
After the fermentation is ended the beans
are washed and dried.

In Semler’s “Tropical Agriculture” the
actual fermentation is briefly touched on,
and the following is a report of the different
methods described :—

“The crudest method of fermentation is
this: A hole is dug in the earth, and the beans
are thrown in and covered with banana leaves

1 See illustration on p. 36 showing sweating boxes
in San Thomé with the cacao covered with banana
leaves.

2 I believe they should be placed horizontally.—
H.H.S.

Dr. Axel Preyer 27

and a thin layer of earth. ' The drawbacks of
‘this process, especially in rainy weather, are
too obvious to need discussing. Instead of
using these earth holes, others erect ‘cemented
pits inside the warehouses, which, after being
filled, are likewise covered with banana leaves
and form a great improvement over the holes
in the ground. Other planters usé casks or
wooden cases for fermentation; others, again,
pile the beans in large heaps on the floors
of the warehouses, covering the heaps first
with banana leaves and then with bags or
thick cloths over the leaves.’ The spreading
out of the beans on tables or trays, or in
regular layers 10 to 20 cm. high, is a process
very much to be recommended. These layers
are covered with banana leaves and cloths,
after which boards are laid on them. The
advantage of this method consists in a
moderate and very uniform heating of the
whole mass.” ;

The preparation of cacao on the Bimbia
Plantation in the Cameroons is described in
an earlier issue of this Journal (Der Tvropen-
filanzer, second year, 1898, p. 9).

E. Friederici says ‘that if the three tank
method is used, the whole fermentation: takes
about sixty hours, and the cacao heaps are
turned about at least twice a day—at noon and

1 See Dr. Preyer’s illustration of a cacao-sweating
tank, p. 30.

8 The Fermentation of Cacao

CACAO TREE IN BEARING, TRINIDAD.

Dr. Axel Preyer 9

evening. The contents of the third tank are
washed in the morning, and those of the other
two tanks are each brought into the suc-
ceeding tanks. The fermenting mass can
easily become over-heated during the second
day, and great care must be taken to avoid
this.”

The fermentation of cacao in Surinam, of
which the following is a short extract, is fully
described by Dr. Preuss in his earlier account
.of his journey out there: ‘Eight wooden
boxes, 1°5 m. broad, 2°25 m. deep and 1°7 m.
high, with inclined bottoms, are placed close
together in the small fermentation house, and
well shut in on all sides. These are filled with
the freshly-gathered cacao to at least 1 m.
high, and one of the boxes must always be
empty. Banana leaves serve as a covering,
and the wooden lid is closed. On the second
day the contents of each box are shovelled
into the succeeding receptacle, one again
remaining empty, and so on with daily
changes for five to eight days. In damp
weather the fermentation goes on better than
in dry. Air coming in spoils the ferment-
‘ing cacao. Only on the fourth day are
the boxes opened so as to encourage the fer-
mentation. In Surinam, the cacao, after being
fermented, is immediately dried, and therefore
not washed.”

Finally, let us glance at the methods in
general use in Ceylon. In this island the

10 The Fermentation of Cacao

system of the three tanks is seldom met with.
Most of the planters ferment their cacao in
covered heaps, and, thanks to this and the care
they take in drying, the cacao is of excellent
quality. Let me describe in detail the entire
process of preparing the cacao as practised on
the Gangaroowa plantation near Peradeniya :—

The ripe cacao’ pods are opened by the
Tamil women as they are brought in. This is
done by first cutting the pods crossways by
means of small knives fixed in a clumsy wooden.
handle, after which they are broken by light
blows, and the contents collected in baskets.
The empty pods are then taken to the compost
or manure heaps. The various qualities met
with (Forastero, Criollo, and wild varieties) are
not separated, but the fruits attacked by canker,
or otherwise diseased, are carefully picked out
and fermented apart. As soon as about 100,000
pods are opened, their contents are placed to-
gether in a heap on a covered-in cement floor,
which has a slight gradient and outlet. The
latter is like a truncated cone, and is formed and
polished by beating with short wooden spades.
Then the heap is at once covered with
double layers of banana leaves; over these
damp jute mats are spread, and the whole is
then covered with a layer of moist earth,
3.cm. to 5 cm. thick. The mats and the earth
are used again and again until it is necessary
to renew them. Thus heaped up, the cacao is
left from five to seven days to ferment, but

Dr. Axel Preyer IL

every other day the covering is taken off, the
heaps stirred round, and again covered over
as before. The vinegar or liquid percolates
through the bottom. The fermentation goes
on slower in, damp weather than in dry; on
the other hand, a certain amount of moisture is
necessary for fermentation. If the air gets in
owing to the faulty covering of the heaps,
decomposition and discolouration of the shells
of the beans take place. The fermentation
is ended when the outer pulp of the cacao
bean is so far loosened that it can be removed
in the succeeding washing. The pulp of well-
fermented beans comes away in the washin

in small particles, not in long, slimy threads.
The washing itself is done in small baskets
which are smooth inside; made from _per-
forated palm leaves, these are filled with the
beans, which are washed where there is a large
volume of water but not too strong a current ;
immersed in this the baskets are subjected to
a steady, constant shaking, after which the
contents are transferred to a large receptacle.
All this takes place very quickly, and a
thorough cleaning of the bean is obtained
without any damage. In wet weather the
washed cacao is dried in layers in a drying-
house by artificial heat; on sunny days they
are carefully spread out in the open on coco-nut-
matting, so that no two beans lie one on the
other. At night the whole is placed under
shelter. After three or four days the cacao is

1 The Fermentation of Cacao

ready for sale, and sold as soon as possible:
this refers to the preparation of first-class
Ceylon produce. Colouring the beans is never
resorted to.

On other plantations in the island modifica-
tions of the methods described are in use; thus
the heaps are made larger and higher, and,
owing toa higher temperature, are fermented
in two or three days less. One planter prefers
to make the heaps pointed, and not round;
others prefer round-shaped heaps.

In cacao fermentation there are many widely
divergent reports as to the development of
heat, as well as the smell of the fermented mass
and the dispersion of the liquid. A short enu-
meration of the reports of the various authors
is shown in the table on the opposite page.

Continuous trials in cacao fermentation are
only met with in isolated cases, and in
Chittenden’s prize essay is found probably the
only attempt at an explanation of the fermen-
tation processes. The author says as follows:
‘‘Unfermented cacao yields the same analytical
results as fermented, although it has been said
that a slow oxidation and formation of new
matters take place. If the fermentation is
properly carried out, the cotyledons are separ-
ated from each other, and the wine-like fluid
of the pulp which forces itself through the
membrane husks. fills the hollow space as well
as the intermediate space between the solid
particles. This is what shows such a physio-

Dr. Axel Preyer iZ
¥ :
Author Method of fermentation Temperature Smell
Aublet Cask without outlet Wine-like, fluid
(Guiana) wine - like,
slightly acid
Chittenden | Several samples fer-
mented well at 80° F.=26-7°C. | Like beer-wort
With the usual Trini- | 115-120° F. =
dad methods 46-49° C.
Morris With the usual West | About 140° F.
India methods = 60°C.
Strickland... | West India three- i)
tank system
In tank I Not over 115- | Pleasant vinous
120° F.=46-| smell. Wine
49° C. fermentation
ie 22 Not under 95°| Acid milk fer-
F. = 35°C. mentation
sf BY oe Ditto... ... | Butyric acid
Semler General rules Never over 60° ste
C. Best at
50° C.
Friederici ... | Three-tank system, fe
: Cameroons :
In tank 1 30-33° C.
a ae 35-38° C.
3. 2 Not over 43-
45°C.
Preuss Three-tank system, | Never over 45°
Surinam
Preyer Heap method (Cey- On second day
lon) like inferior
wine must

In the upper half ...

>» lower half ...

30-40" C.

Outside tem-
perature up to
30° C.

On fourth day
strong alco-
holic, like in-
ferior wine

The separated
liquid like
fermented
and sour milk

logical influence, and on which depends the
aroma, whilst the beans to a certain degree are

stewed in their own juice.

Further, the osmose

14 The Fermentation of Cacao

(the tendency of two different fluids,’ when
separated by a membrane, to pass through the
pores and mingle) through the seed shell in
the fermentation is easy to demonstrate by the
insertion of the fermented beans in fuchsin
solution. Then also, after the drying of the
resulting hollow spaces, an elastic pressing
togéther of the shells becomes possible, and
the ability to obtain this ‘spring’ is a sign
of a properly finished fermented bean. The
different claims of the various cacaos are
dependent on the percentage of their fats,
Concerning Strickland’s tank methods, it may
be further said that in tank No. 1 there is wine
fermentation owing to Saccharomyces cerevisia,
and probably at the same time milk fermenta-
tion (Peniciliium glaucum). Brought into tank
No. 2, the cacao shows an acid reaction ; further
lactic acid fermentation takes place in a lower
temperature. The lactic acid will later (in
tank No. 3) change into butyric acid, after the
formula—2C,H,O, = C,H,O, + 2CO, + 2H.
The pleasant smell disappears and butyric acid
is also traceable. Decomposition easily sets in,
with formation of nitrous acid and nitric acid,
as well as injurious gases.” Further, Chitten-
den recommends in cases of defective fermenta-
tion that a repeated fermentation with the
addition of some invert sugar and yeast be
carried out.

In order to obtain the nearest or most exact
explanation of the nature of the fermentation

Dr. Axel Preyer 15

of cacao, I carried out, when in Ceylon, a series
of microscopical examinations of the fresh
beans as well as of the fermented mass, to
which numerous practical tests were added.
The complete report is as follows :—

The fresh cacao bean as it comes from the
ripe fruit is a longish, egg-shaped body varying
in size, chiefly 2 cm. to 2°5 cm. long, and
I cm. to 1°5 cm. thick; it is white, pale pink,
or pale yellowish. With a cross cut one can
distinguish two coverings, which surround an
inside hollow space, outside the pulp, but
inside the shell proper. In the outside of the
hollow space the little germ is found, sur-
rounded by two large bud leaves (cotyledons)
which are covered with a very thin skin over
all their surface.

The pulp (Schleimschicht), which covers the
seeds as well as the sides of the inner hollow
space of the cacao bean to a thickness of
o'5 mm. to 1 mm., usually consists of large cells
of irregular shape, originally parenchymatous
cells; between these large intermediary cell
spaces are found. The pulp cells swell verymuch
in warm water. Small to larger agglomerations
of a granular substance form the contents of
the cells; these consist chiefly of gum, whilst
the cell walls consist of cellulose. Besides
this, sugar is. found in the fresh pulp; on the
other hand, albumen could not be found in dis-
tinguishable quantities. The colour of the
pulp is pure white, only by fermentation does

16 The Fermentation of Cacao

it become a reddish to brownish colour; the
taste of the pulp is sweet and gum-like.

The shell of fresh cacao beans is of a
leathery nature. It is firmly surrounded with
the pulp, but free on the inner side, so that
a removal of the leathery skin from the cotyle-
dons can easily be effected. The leathery skin
is O'5 mm. to 06 mm. thick, and consists of
three layers of different cells: (1) A single
(and here and there a double) layer of thick-
walled stony cells, which are packed closely
together, and connected with the compressed
cells of the pulp on the inside. (2) A thick
middle layer of fibrous tissue which surrounds
chlorophyl]l-bearing cells, and contains spindle-
shaped hollow spaces. (3) A single and occa-
sionally double layer of parenchymatous cells
which form from within the epidermis of the
shells of the beans ; the cells are mostly empty.
The colour of the leathery skin at first is a
pale brownish; but after the fermentation it
becomes yellow, and then turns red to dark
brown.

The thin and shiny transparent skin which
entirely envelops the whole surface of the
cotyledons consists of a single layer of very
regularly formed empty parenchymatous cells,
which do not grow firmly together with the
germ leaves, but can be removed.

Lastly, the cotyledons form. together a
longish egg-shaped “body with a smooth sur-
face ; inside they lie in numerous deep folds on

. Dr. Axel Preyer 17
each other, and round the germ; they are of
soft nature, white, yellow, or violet in colour,
and possess a strongly bitter taste. The cotyle-
dons come from the parenchymatous tissues.
In the cells are deposited reserve substances
in the shape of thickly compressed globules,
such as fat, starch, and albumen.!

If several samples are taken from a heap
of cacao beans on the second day after fer-
mentation has been started, and the outer
pulpish substance be examined under a strong
microscope, countless organisms of various
natures show themselves in and about the
pulp cells. In Ceylon were found yeasts of
ellipsoidal or rounded spindle-shaped form,
besides bacilli, which occurred singly or in
pairs, and spores of various sizes on the
cacao beans lying on the surface, also moulds
(Penicillium among others). On the other
hand, in Java several other kinds of wild
yeasts were noticed, including pointed, spindle-
shaped and cylindrical forms; also spores,
bacilli, and spirals.

The question then arose whether the changes
were produced during the fermentation by en-
zymes, generated by the living plasma of the
cacao seeds, or the assimilation of the existing
bacteria, or by the vitality of the yeast cells.
‘The production of enzymes in the living cacao
seeds or beans can take place by the germs;

1 See illustrations in Dr. Nicholl’s Essay.—H. H. S.
Z

18 The Fermentation of Cacao

this, however, never appears to be the case
in fermentation, the germ soon being killed
-owing to the fermenting process, and therefore
fermented seeds are not germ bearing (this
Hart has already mentioned). On the other

PULP OF FRESH FORASTERO CACAO BEANS FROM CEYLON.
Mag. X 330.

thand, it would be possible that the other
plasma-containing cells generate the enzyme.
Against this, as well as against the second
question, whether the bacteria are the in-
citers of the fermentation,. there is the fact

Dr. Axel Preyer 19

that neither in the total exclusion of :living
organisms in general, ‘nor in the absence of
yeast cells, do the known phenomena of
fermentation take place ; at the most it is only
with the presence of bacteria that the forma-
tion of acidity or decomposition follows. Of

a. —» Gee == Se ae @
—————— A ==

on
ss

THE SHELL OF A Ripgz CACAO BEAN-—FORASTERO
VARIETY—FROM.CEYLON. Mag. x 70.

a, Epidermis ; 4, fibrous tissue with chlorophyll-bearing
cells ; ¢, stone cells ; ¢, compressed chlorophyll ceils contain-
ing pulp; ¢, cells containing pulp. : ‘

course, in the case of fresh cacao beans which
are exposed by the exclusion of air organisms,
a darker brown colouring soon takes place, but
that is all; further changes do not take place
either in the colour of the cotyledons or in the
bitter taste; the pulp also is not so easily
washed away as in well-fermented beans.

20 The Fermentation of Cacao

The living yeast cells in the pulp are
apparently the inciters of fermentation ; ac-
cording to Buchner, the chemical changes they
produce with the help of the existing enzyme
always deserve consideration when studying.
cacao fermentation. After several attempts.
at yeast cultivation in Ceylon, I was able to.
isolate one variety, and grow it separately.
This one is always found in Ceylon plantations.
on fermenting cacao, and in the fermentation
trials it gave by far the best results. It
appears, without doubt, that other kinds of
yeast, perhaps even European beer and wine
yeasts, can create a fermentation of cacao.
However, the ideal yeast will probably only be
discovered by the careful cultivation of those
which at present seem to be most satisfactory.
As a starting point the kind of yeast found
in Ceylon seems to be very suitable. This
is distinguished from all the Saccharomyces:
described hitherto, or at the most it slightly
resembles S. e¢lipsordeus (1. Hansen), and
S. membranefaciens. 1 would describe the
new variety as follows :—

The sprouting fungus of cacao fermentation
—S. theobrome (Preyer)—is of longish, ellip-
soidal shape, in the midst of almost cylin-
drical cells, which, though separate, lie together
in short chains or in heaps. The length of a
cell measures on the average ‘00615 mm., with
a cross diameter ‘0031 mm.; such cells are
found in the middle of a pure bacilli culture in

Dr. Axel Preyer oa

nourishing liquid. The cells of the sediment
have a short, compact formation, and those
‘of the mycoderm skin are of very long cylin-
‘drical form, generally with rounded ends, the
latter variety being up to ‘032 mm. long. The
‘contents of the cells consist of plasma and
vacuols (vakuolen = hollow spaces in the
protoplasm of a cell), and these are, in most
cases, easily discernible. In the long myco-
derm skin-cells three or four vacuols are
also to be found. With the withdrawal of
nourishment, Askospores form in eighteen to
twenty hours (in 25° C.): The spores are
very small, and fill the cells in large quanti-
ties. S. ¢heobrome are found in Ceylon on
fermented cacao. A pure bacilli culture .can
be made in a decoction of fermented cacao
beans. In raw sugar solution yeast is not
found, and no fermentation takes place, but
degenerate dwarf-shapes form, and finally die
off. In the cacao decoction the fungus begins
to form after one and a half to two days
(at 25° C.), at first a white, later a grey,
mycoderm skin, which becomes light red on its
upper edge (on the walls of the test tubes),
The yeast germinates in cacao pulp of alcoholic
fermentation.

Thus are explained a few facts about the
nature of cacao. fermentation ; but it. still
appears doubtful how the contents of the
seeds, z.e., the cotyledons, can become affected
through the outer fermentation of the pulp.

22 The Fermentation of Cacao

Cacao YEAST. S. theobrome, Preyer.
A, C, D, x 800; B, x 1,000.

A, Long mycoderm skin cells; B, pure culture from pulp
liquor; C, yeast sediment; 1, askospores, formed after
eighteen hours. , ‘

Dr. Axel Preyer — aa

Chittenden at first expressed the opinion that
the soluble or liquid matters penetrate through
the leathery skin in the seeds, and produce the
change in taste and colour. He proves the
possibility of this theory by a trial, in which
the cotyledons of a cacao bean were coloured
red after being immersed in a fuchsin solution
for a few hours, The leathery skin is also
permeable, at least by some substance. I re-
peated this trial in the following manner. On
the one side I used fresh seeds, on the other,
seeds fully intact but fermented for several
days ; both were put into an alcoholic fuchsin
solution, and after twenty-four hours cross-sec-:
tions were examined. The fresh beans showed
(even after forty-eight hours) no trace of a red
colouring of the germ leaves ;. the fuchsin solu-
tion had only percolated through the pulp, and
no further. On the other hand, the fermented.
seeds had intensely red-brownish coloured
cotyledons after one still (more after two) day’s
immersion, whilst other fermented seeds not
treated with fuchsin were of a pale brownish
colour inside; therefore the fuchsin colouring
matter had penetrated through the hitherto
impermeable leathery skin. During the micro-
scopical examination of the coloured beans it
was found that through the fermentation a
loosening of the hard cells takes place, so that
the hitherto impenetrable layer is now loosened,-:
exposing the middle fibrous layer and, more.
especially, allowing the inner cells to be acted.

24 The Fermentation of Cacao

upon. Whether the loosening is brought about
through dissolving agents which are produced
in the fermentation or through pressure from
inside remains uncertain.

As to what chemical combinations arise in
the fermentation, to exert an influence upon
the quality of the cacao, chemical investigation
must determine. Here I am only able to note
that in the fermented pulp are found ethyl
alcohol, and in the places covered with mildew
fungi, bad-smelling alcohol (probably methyl
among other stronger alcohols), lactic acid, and
similar substances, and, finally, aromatic sub-
stances.

The principal result of the activity of the
bacteria is the formation of organic acids, and
in those experiments in which bacteria were
absent no free acid could be detected. The
organic acids formed are chiefly produced by
the action of bacteria. Since, as is shown
later on, acid fermentation of the pulp affects
the taste of the cacao unfavourably, such
bacteria are to be considered as harmful to
the fermentation process.

After it was proved by comparative tests
that the S. ¢heobvoma@, as a rule, was the best
ferment, further tests were made to find out
under which conditions this yeast thrives best
and produces the most superior quality of cacao.
For this purpose it is necessary to characterize
shortly the attributes of a superior cacao.
Morris says: ‘‘If well prepared the outside

Dr. Axel Preyer 25

shell should be hard, crisp, and easily detached
from the kernel ; the latter must be hard, light
coloured, and easily broken under pressure.
A light chocolate or cinnamon colour, combined
with even break, are signs of the highest
quality. It can also be added that a cinnamon-
coloured shell is also much to be desired, and
an aromatic, not bitter, taste for the kernel.”

The results of the fermentation trials which
were undertaken with equal quantities of fresh
cacao beans in large glass cylinders are re-
capitulated on pp. 26 and 29 in the form of
a small table.-

Whatever, in the first place, may be the
‘cause of the inoculation of the unfermented
mass with bacilli, it can be seen that the unin-
oculated lots, Nos. 1 and 4, developed a sourish
smell during the fermentation, a rapid growth
of bacteria, and, after drying the beans, a,sour
and bitter taste as well’ as an irregular or un-
even inner colour or break. Referring to the
temperature, | wished to ascertain the highest
point up to which the cacao beans can be
heated and still give a good article. In this
experiment the peculiar circumstance mani-
fested itself, that on the third day the outer
colour was spoilt—‘‘ scorched”—whilst the
pulp all through was not properly loosened,
and could only be washed very badly. In the
lower temperature, 23° to 26° C. (air tempera-
ture), excellent results were achieved. A slight
heating at all events seems to be desirable,

26 The Fermentation of Cacao
1 | Sy 8 2 DurinG FERMENTATION
2) 35 ay » .
E) yess] 3 ;
z 3 258 5 Air Water After three to six days Osa
& 2 eas 8 Microscopical ae = :
aoe a Smell ppeetst ae ay
1 | Notino-} 23 to | Access | Remains| Very sour! Numberless | Suffocat-
culated | 26 standing and bacteria, a ing,
alcoholic | few yeast sour
___ cells
2 {| Inocu- | ,, i 99 Aromatic,| Numerous | Sourish,
lated pleasant, | yeast cells, | aromatic
wine-like| later no
bacteria
3 oe », | Exclu- | Runs off| Pleasant, | Many yeast | Sourish,.
sion wine-like| cells and | alcoholic
bacteria ;
4 | Notino- a Access | Remains] Sourish, | - oH —_
culated standing | alcoholic
5 : Inocu- ra #9 5 Aromatic,| Numerous =
: Jated alcoholic | yeast cells,
| also
: bacteria
6 is ‘3 Exclu- wis Sourish, | Few yeast —
{ . sion alcoholic | cells, many
: bacteria
7, 8 6 Access | Runs off | Aromatic,| Numerous —
| alcoholic | yeast cells
i and
bacteria ,
8, =| 38 to ay Remains “5 Many yeast —
42 standing cells and
/ bacteria
9 Le : 48 to ” ” ” ” oa
y 5
10 a 52 to 5 on Decom- | Mildew, _—
55 posing | fungi and
; few yeast
cells

Remarks.—All the glass cylinders were covered over with glass plates,.
which, in the trials arranged ‘‘ with air access,” were raised by a layer of
wadding. The temperature in trials 8, 9 and 10 was not regular, owing
to the lamps not burning properly. The trials under ‘‘ water remains
standing” were placed in upright cylinders, those with ‘‘ water running

Dr. Axel Preyer ay

Washing on

Qua.iry oF Drizcp BEANS AFTER FivE To Six
Days’ FERMENTATION.

ee

: After ten
sixth day days’ fermen-
tation
naeose |/Sicatoee | eee Taste
Moderately Very Uneven, |- Moderate | Somewhat | Too dark,
good light, | moderate sour, bitter |black spots,
good and bitter,
aromatic aromatic
Superior | Cinnamon |Very good | Very good Mealy, Too dark,
red, : aromatic, | taste good
superior slightly
bitter
Bad Light, + + es sy
good
Good Moderate,| Bad, Good Bitter, f —
spotty | irregular somewhat
aromatic
Superior | Cinnamon | Superior! Good | Slightly bit- —
red, ter, very
_ Superior aromatic,
mealy
Fairly good | Moderate Grey, Bad, too | Bitter, not a
moderate hard aromatic,
. bad
Moderate Light, Good 50 Slightly bit- _
very good ter, very
aromatic,
mealy
After thjree days’ ferimentation
On third | Very bad, Good Good Somewhat —_
day bad _ | black spots bitter,
: aromiatic
+ Very bad, Good, i a —_
black, |Somewhat
spott dark
. y Good —

off” in inverted cylinders.

The washing is classified respectively as

‘superior ”’. or ‘‘ good” if the. pulp separates easily and in small shreds,
or ‘‘ bad” when it is difficult or impossible to separate. All the trials
were made with yellow and red fruits of the Forastero variety.

28 The Fermentation of Cacao

in order to reduce the period of fermenta-
tion, nevertheless it is as well to keep as much
as possible within the limits of 28° to 35°C.,
as occasionally at 38° to 42° C. an inferior
colouring is obtained. That an even tempera-
ture should exist-as far as possible through the
whole mass to ensure the production of a
uniform quality goes without saying. It does
not seem difficult to determine whether access
of air or its total exclusion is more favourable
for the process of fermentation (supposing that
the penetration of organisms from the air is
stopped), as neither in trial 3 nor 6 were the
best qualities throughout obtained.

On the other hand, it is less easy to say
whether it is more advisable to let the existing
fluid drain away as it forms, or let it. remain
about the fermented beans. If the trials 3 and
7, and 2 and 5, are compared, the latter, which
were fermented ‘“ wet,” turned out considerably
better. On the other hand, trial 6 shows that
the non-removal of the liquid, together with the
exclusion of air, yields very lean cacao. Finally,
as regards the duration of the entire fermen-
tation, special trials were made. Samples of
trials 1, 2, and 3, which were fermented* ten
days, all showed too dark an inner and outer
colour, but with a five to six days’ fermentation
at the low temperature stated, the cacao was
found to be normal. General rules for the
duration of the processes cannot be given, as

the time is governed, even more than the other

Dr. Axel Preyer 29

factors, by the temperature, the kind of cacao,.
and the degree of ripeness of the fruit.

If we recapitulate, the method of fermenta-
tion used in the two parallel tests 2 and 5,
proved best, especially as the colour of the
seed shells and the taste of these were identical
with those of the most superior plantation pro-
ducts. If we compare this treatment with the
various methods of the cacao planters described
at the beginning of this treatise, we find the
oldest record of a ‘“‘ wet” fermentation in casks,
viz., that reported by Aublet in 1775, is,.
strange to say, the one that comes nearest to.
it, whilst the good smell and taste of the wine-
like Auid also point to an excellent fermenta-
tion. Of course, one is not forced to use small
receptacles, large tanks can be used just as.
well. If I have described a method which is.
likely to yield good results in most cases, I do.
not wish in doing so to offer such instructions.
or suggestions as general guiding rules, much
less do I profess that they are infallible, for, as.
already stated, the entire fermentation process
is dependent on numerous circumstances which:
may cause it to be necessary to introduce a
modification in the manner of procedure and
preparation.

Analogous to the tank system, divisions of
cemented brickwork are constructed some 2 m.
broad, 3 m. to 4 m. long, and only 30 cm.
deep, with a drain, which, however, is only
opened for cleaning, being otherwise firmly

30 The Fermentation of Cacao
closed with a stone stopper. Corresponding
with the directions given in Semler’s “Tropical
Agriculture,” the fresh gathered cacao beans
are poured in uniformly in layers 20 cm. high,
so that the whole bottom surface is covered,
up to the side walls; then a small quantity of
good cacao yeast is spread over the mass, and
the beans can, as desired, either be covered
with banana leaves or left uncovered. The
division is closed with a wooden lid, provided

SECTION OF A TANK FOR THE REGULATION OF THE
CACAO-SWEATING PROCESS.

a, Cement wall-work, each division 2 m. wide, 3 to 4 m.
long, 30 cm. deep; 4, stone stopper or bung; c, cacao beans ;
.d, wood cover or lid with air-holes ; e, coco-nut or jute mat-
ting ; f, layer of sand, 5 to 8 cm. thick.

with many ventilation holes, but with a tightly
fitting edge. Over this, clean (often washable)
mats are laid, and on the latter is a layer, 5 cm.
to 8 cm. in depth, of damp, clean sand. In
this manner the air is not shut out, but the
penetration of bacteria is stopped.

About every forty-eight hours the cacao is
turned over as quickly as possible, and then
spread out as before; too high a temperature

Dr. Axel Preyer 31

need not be feared. On the other hand, the
possibility of sourness must be carefully
watched, and if this becomes too pronounced,
the liquid must be drained off. After five to
seven days, as a rule, the fermentation is
finished, and the whole mass is washed. The
progress of fermentation is checked by examin-
ing small samples obtained when turning over
the layers of beans. On account of this, as
well as for the drying process that follows
it, both the methods of fermentation already
described as being used on the Gangaroowa
Plantation (Ceylon), and the drying process
employed there, are to be recommended. ~

Although I have, in the above communi-
cation, provided some details regarding the
causes of fermentation and the methods
employed to induce fermentation in cacao,
there still remains a difficult but important
point to be solved, wzz., the recognition of the
chemical changes that take place during the
fermentation and drying, and of the inter-
mediary and final substances formed during
the process. It would still be too risky before
even the composition of the fresh cacao bean
in its various parts is fully known, to wish
to advance chemical hypotheses about the
processes and changes that take place during
the process. of fermentation; but it is very
probable that, later on, the chemist will play
an important part in the preparation of cacao
on the estates.

Go
to

CHAPTER II.
By Dr. OSCAR LOEW.

With some Comparative Notes on the
Fermentation of Tea and Coffee.

AttHouGH much has been written about
the fermentation of cacao, there stills exists a
great difference of opinion in regard to the
process, its purpose and necessity, and the
kind, of action involved in it.

Herbert Wright, in his exhaustive work on
cacao,’ mentions yeast cells’? as the most impor-
tant organisms causing the fermentation, while
other authors attribute it to unorganized fer-
ments, others again to bacteria, and even the
changes due to germination were supposed to
play a réle in it.

According to Sir George Watt, in his Dic-
tionary of the Economic Products of India? :—

1 « Theobroma Cacao or Cocoa.” Colombo, 1907,
p- 108.

2 According to Dr. Axel Preyer (Tvopenpflanzer, 5
(1901), pp: 157-173), a special kind of yeast, which he
named Saccharomyces theobvome, effects the best fermen-
tation in Ceylon. See Dr. Preyer’s essay, p. 20 and
elsewhere, also Dr. Nicholls’s, p. 225, et seg.

8 London, 1893, vol. vi, pt. 4, p. 44.

Dr. Oscar Loew 33

Dr. OSCAR LOEW.

w&

34 The Fermentation of 'Cacao

“The coolie dexterously strips all the beans
off the centre stalk (placenta), The empty
pods are then thrown round the trees and act
as manure, while the beans are removed to the
fermenting cistern. It takes from five to nine
days to properly ferment the cacao and it is
then ready for working. It is trampled first,
as in coffee, with the feet, and then oe
in baskets and carefully hand-washed’, |
have no doubt that before long some means
less expensive will be found for washing . . .
The prices obtained for it will depend, to a
more considerable degree, on the careful atten-
‘tion to the curing than in the case of coffee.”

Safford, writing on cacao in Guam,” says :—

“Cacao beans are sometimes kept in jars
and allowed to ‘sweat’ or undergo a sort of
‘fermentation which improves their flavour, but
this custom is not universal. Many families,
after having dried the beans in the sun, keep
them until “required for use, when they roast
them as we do coffee, grind them and make
them into chocolate, Chocolate made from
the newly ground bean is especially rich and
aromatic.”

.Hinchley Hart* writes :

“The prime object of sweating or fermenta-

1 Such methods are followed in Ceylon and the East,
but not in America, as a rule.-—H. H. S,

2 « Useful Plants of Guam.” U.S. Nat. Mus., Contrib.
Nat. Herbarium, 9 (1905), p. 387.

8 “Cacao.” Trinidad, 19c0, 2nd ed., p. 38.

Dr. Oscar. Loew 35

tion appears to be to change the inside portion
of the bean by absorbing into it products
obtained from the fermenting pulp, and where
this is not fully accomplished by any of the
methods the bean is classed as unfermented,
and the: product is generally of lower value.”

The changes brought about by the fermenta+
tion have been minutely examined by Prof.
Harrison, the well-known chemist and Direc-
tor of Agriculture in British Guiana. Some
of the changes observed, as, for example, the
decrease of protein in the seed and the increasé
of amido compounds, are only incidental and
not of any importance, since they do not affect
the colour, which is simply due fo. the action
of an oxidizing enzyme in the seed.

The principal conclusions reached by
Harrison’ ‘are that the process of ‘‘fermenta-
tion or sweating in cacao consists in an
alcoholic fermentation of the sugars in the
pulp of the fruit accompanied by a loss of some
of the albuminoid and indeterminate nitro-
genous constituents of the beans, . . . and
some parts of the carbohydrates other than
sugars undergo hydrolysis and either escape
in the runnings from the. boxes in the form
of glucose, or undergo in turn the alcoholic.
and acetic fermentations.” Further he de-
clares: ‘During this change some of the

1 Pyoc. Agr. Soc. Trinidad, 2 (1896-97), p. 250; Hart,
*Cacao.”’ Trinidad, 1900, ‘and ed., pp. 106, 107.

The Fermentation of Cacao

36

‘ne ay} jno Suninys Aqyensed Aq uolejuswsay a8einoous soAvay vueueq ou yf

‘(ANOHL NVS) SaXOY ONILVAMS YO ONILNANNAY FHL NI OVOVO

Dr. Oscar Loew 39

astringent: matters, to which the somewhat
acrid taste of the raw beans is due, are also
hydrolyzed, and thus a marked improvement
in flavour is gained.” Finally he adds: ‘‘ This
work has necessarily only resulted in a partial
and incomplete study of the results of the
fermentation.”

The so-called fermentation is carried out
either by heaping the fresh ‘seeds, after
separating them from the shell, on the floor,
or placing them in receptacles and covering
them with banana leaves or with cloth. The
floor or the receptacles slope so that the
watery products can escape during the fer-
mentation. A period of two to. six days,
according to circumstances, is usually allowed
for fermentation. The height of the heaped
seed measures Ito 1°5 metres and over. In
some countries the highest temperature allowed
for fermentation is 45° C., in others 50° C.
According to Hart’ there is “danger in
allowing [the temperature] to rise above
140° F. [60° C.j,? as the character of the
product is sure to suffer.” An apparatus
has been recently devised by M. Schulte in
which a constant temperature of 60°C. is
maintained.’ In this case the yeast is fully
excluded and bacteria with few exceptions

1 «© Cacao.” Trinidad, 1900, and. ed., p. 42.

2 Note, p. 248, that Nicholls says 110° to 120° F. is
the optimum temperature.

8 See Dr. Schulte im Hofe’s essay, p. 95, ¢¢ seq.

The Fermentation of Cacao

38

eno py
a or
oo et
ggg
ba a any
mS Oe,
ee eS
ees
a2 =
gin ©.2
LS H »
S Soo
ise
CDE g
po
B23 5
n G =
0) ee
Oo
EEvo
e’ vo
58
OD
OOS
pa) 7
aaEo
a.£ 0%
aa
~-Be
2) oe
Ad0'a
eOQ >

ff. S., Hard outer shell

Fic. 1.—Structure of cacao fruit :
S..S., soft inner layer of fruit shell; ?., pulp of seed

of fruit;

or slime tissue ; S. &., seed with testa or envelope ; C., core or

placenta.

criticism of the

his

in

Maurice Montet!

apparatus.

Journ, Agr. Trop., 5 (1905), No. 52, p. 297.

Dr. Oscar Loew: 39

The rise of temperature amounts to about
5° C. in twenty-four hours, and after four
days the fermenting beans show generally an
elévation of 18° to 20° C. above the tempera-
ture of the surrounding atmosphere. The
more or less rapid rise of temperature in the
fermenting pile depends, of course, upon the
height of the pile and upon the temperature
of the surrounding air.

The cacao fruit resembles a cucumber in
shape, but the form is subject to certain varia-
tions. The shell is of violet, red, or yellow
colour, sometimes even nearly white, 15 to 25
cm. long and 6 to 10 cm. thick. The shape
of the seed is more or less round, often
laterally compressed or flattened, when it
resembles the bean of Phaseolus; its length
varies from 2 to 2°5 cm., the diameter from
o'8 to 1°8 cm. Between the fleshy and
corrugated cotyledons, showing convolutions
on the surface, lies the bitter, purple embryo
with its white chalaza. The cotyledons of
one variety are white in colour. As many
as 50 seeds may exist in one fruit.' The
loose parenchymatous slimy tissue (pulp)
surrounding the testa of the seed appears to
be of a similar nature to the tissue forming the
soft inner layer of the hard fruit shell. The
structure of the entire fruit is somewhat

1 The average would be below 40, however, including
the small and lean beans at the extremities—H. H. S.

40 ‘The Fermentation of Cacao

complicated, and nature has evidently taken
much pains to protect the embryo by four
different envelopes. Figure 1 will suffice to
explain the structure. .

The chief purposes of the fermentation
process are:

(1) Removal or contraction of the pulp
surrounding the seeds.

(2) Loosening of the connection between.
the seed and its testa.

(3) Development of colour and improvement
of taste.

Some authors hold that the heat of the
fermentation is required to harden the interior
of the bean, and also pass it to a second
fermentation ; further, that another change
consists in the hardening or toughening of
the testa of the bean, whereby brittleness is
avoided during drying, and thus the seeds are
better protected against the entrance of mould
fungi.’ Various authors also ascribe to the
fermentation a great influence upon the
development of the aroma.

As regards the first of the above-named
purposes, namely, the removal of the slime
layer attached to the seed coat, a somewhat
similar process occurs in the fermentation of
coffee. (See p. 59.) The first step is the
development of numerous yeast cells, which
find ample nutrients in the sweet juice oozing

* Hart, Cacao.” Trinidad, 1900, 2nd ed., pp. 35, 49..

Dr. Oscar Loew / 4!

from the pulp. The yeasts are chiefly Sac-
charomyces ellipsoideus and a certain amount
of S. apzculatus (see also p. 62, re “ Coffee
Ferments”), which develop rapidly. These
organisms occur on fruits, as well as in the
dust of the air and on the surface of the soil,
together with numerous bacteria. The alcohol
formed in the fermentation of the sugar from
the pulp by these yeasts kills the cells of the
superficial strata of the pulp or slime tissue,
and as its juice passes freely to the outside,
nourishment is given to innumerable bacteria,
among them the widely distributed acetic
bacillus. The respiration of these organisms
and the fermentative activity generate heat,
and gradually a considerable elevation of tem-
perature is reached.

The juice on the surface now assumes a
strong acid reaction, due to the oxidation of
alcohol to acetic acid, and this suffices to
destroy the remaining cells of the slime layer,
causing thereby a considerable shrinkage of
it, and also a further discharge of juice, as
the cytoplasm of the dying cells becomes
permeable to the interior juice. Thus a
considerable amount of liquid gathers at the
bottom of the receptacles and, since this liquor
has an agreeable sour smell and taste, it is
used in some factories as vinegar. By the
bacterial action the attached pulp is further
loosened from the testa to some extent and
can be washed away, as is done in Ceylon.

42 The Fermentation of Cacao

In many parts of Central America, however,
the shrunken pulp is dried with, 2.2. on, the
beans, which are shipped in this condition to
other countries.

Cacao beans, when fermented and_ well-
washed, show a uniform yellowish or brownish
colouration of their testa. The testa of un-
washed fermented beans do not show a uniform
colouration on account of the adhering films
of fermented and shrunken pulp, which has
turned from the original colourless condition
to a violet brown colour, and which is reduced
from the original thickness of o'1 to o'2 cm,
to a mere film. An advantage of removing
the remaining films by washing consists doubt-
less in the greater rapidity of drying, where-
by the danger of attack by mould fungi is
diminished. Eugene Lange’ holds that the
extra trouble is not compensated by the addi-
tional price obtained for washed cacao. Never-
theless, the washing of the cacao has been
recently introduced in Trinidad.’

When pulped cacao is not fermented, but
simply dried in the sun, the slimy layer around
the testa shrinks considerably, but not to such
insignificant thin films as after fermentation.
When the entire juice of the slimy layer is
simply dried up instead of being removed, a
hygroscopic conditton. of the product results,
which in moist weather becomes sticky and

1 Agr. Record. Trinidad, 4 (1891), pp. 105-107.
2 Tt is, however, very seldom used to-day.—H. H.S.

-Dr. Oscar. Loew 43

might support fungus growth. Hence, fermen-
tation is preferable to a simple drying process,
and after washing yields a much cleaner
product.

In the fermentation of coffee the slimy layer
to be removed from the testa (parchment
envelope) is much thinner than that of the
cacao seed. Hence, the fermentation of coffee
is of much shorter duration that that of cacao.

In regard to the second purpose above
mentioned, namely, loosening the connection
between the seed and its testa, it must be
mentioned that by the death of the seed,
caused by the elevation of temperature during
fermentation to 40° to 45° C., some contraction
takes place and the seed recedes somewhat
from its walls. Later on, in the manufacture
of cacao from the fermented and dried beans,
these are roasted and some further contraction
of the seed is caused. The testa having lost
its hygroscopic water by the heat, now can be
easily separated, especially while still warm
and brittle.

An important change, also due to the fermen-
tation process, is the production of a fine brown
colour. The effect of the fermentation in this
direction is, however, not a direct, as supposed
by many, but an indirect one, and may be
secured by simply drying the bean. Sun-dried
beans are uniformly deep brown. When the
fresh seed is cut, the surface thus opened will
turn from the original violet toa deep brown

44 The Fermentation of Cacao

colour within a short time, while boiled seed
thus treated will not show any change of colour,
even after many hours’ exposure to the air.
This is in full analogy with similar phenomena
observed very. frequently with plants, and is
due to the presence’of oxidases or oxidizing
enzymes. When cells are killed by being cut
open or in any other way that will not injure
the oxidases, these will, upon the death of the
protoplasm in which they are stored up, be
liberated and at once commence their activity,
easily recognized by the early appearance of a
brown, black, or red colour. These colours
are often due to the oxidation of various
kinds of tannins originally present in the juice
or cell sap. If, however, the death of the
protoplasm is produced by strong acids or
boiling temperature,’ the oxidases will also be
killed and no colour change will be noticed, as
the tannins and other readily oxidizable matters
in the juices cannot ‘easily take up the
atmospheric oxygen without the assistance of
oxidases.

A further control experiment was made in
which the pulped cacao (seed with testa and
attached slime layer) was boiled for about
twenty minutes with a 2 per cent. dilute sul-
phuric acid. The slimy tissue contracted, and

‘ Such a case is observed in the curing of tobacco,
whereby a fine brown colour is produced.
2 The killing temperature for oxidases is 20° to 30° C.
higher than that for protoplasm or living matter.

Dr. Oscar Loew 45

together with the swollen testa was easily
separated from the seed. These seeds showed
a pure red colouration on the outside, while
the interior was violet, and no trace of brown
colour appeared even after many hours’ ex-
posure to the air, since the oxidizing enzyme
(oxidase) had been killed, together with the
living matter (the protoplasm of cells).

The seeds commence to die when the entire
fruit is kept for several days at 40° to 45° C.,
and the browning can be observed progressing
from the surface of the seed toward the interior.
By becoming over-ripe, the soft interior strata
of the fruit shell, as well as the slime tissue
around the seeds, contract more or less, and a
hollow space is formed between the fruit shell
and the seeds with their adhering slime tissue.
Air diffuses into this space, and tne reason for
the brown colour produced by oxidation within
the fruit becomes apparent. During the fer-
mentation process the browning does not often
go farther than this, and the interior of the
seed often continues to show the original violet
colouration. It is then that the subsequent
drying process, which admits air abundantly
by diffusion through the testa, completely
finishes the browning process. Some further
darkening can take place during the roasting
process when powdered cacao and chocolate
are made from the fermented beans.

The colour change of the cacao seed is
no doubt similar to the colour change in the

46 The Fermentation of Cacao

preparation of black tea, in which it has been
positively proved’ that an oxidizing enzyme
acting on a specific tannin is the real cause of
the blackening of the leaves. When the oxi-
dizing enzyme of the tea leaves. is killed by
steam, the leaves retain their green colour and
never turn black, thus giving us the green tea
of commerce.” ;

Tea leaves contain 7 per cent. tannin and
over, and the production of a black colour from
this tannin commences as soon as the leaves
die, which takes place when they are kept in
heaps after picking, and are deprived of sun-
light (death by starvation). Indeed, black tea
contains less tannin than green tea. In order
to increase the black colouration, the leaves are
rolled, which brings their juice to the surface,

1K. Aso. “Bul. Col. Agr.” Tokyo, Imp. Univ., 4
(1900-1902), p. 255. It may be of interest to readers to
remember that, from 1893 to 1897, Dr. Loew occupied’
the important position of Professor of Agricultural
Chemistry at the College of Agriculture, Tokyo Univer-
sity. See Tropical Life, February, 1910, p. 32,—H.H.S.

2 Even to-day we are told that whilst great strides
have been made since the formation of the Scientific
Department, it is doubtful, according to the Dooars
correspondent of a contemporary of the Indian Planters’
Gazette, if there is any agricultural pursuit about which
less is known by the ‘men occupied in it .than tea.
Especially is this the case in the tea house. We succeed
in turning out quite passable tea, and are at times vain
enough to think that we have made as good tea as
it is. possible to produce from the leaf at our disposal.
But the present methods may be revolutionized at any
time by new discoveries. Take one branch of manu-

‘Dr. Oscar ‘Loew: 47

and the access of air accelerates the blackening
‘process.

A case in which tannin is changed by partial
oxidation for the sake of removing the
astringent taste is observed in the curing of
the fruit of certain varieties of persimmon
(kaki) in Japan. By the curing process,
which consists in keeping the fruits in alcohol
vapour or in subjecting them to slow desicca-
tion in the sun, the tannin is changed, in con-
tact with an oxidizing enzyme and oxygen, to
a brown, tasteless substance.' The fruit thus
acquires an agreeable taste.

Since a moderately brown colour is also pro-
duced in white “nibs,” free of cacao red, it
follows that the brown colouration is not due

facture by fermentation, and we find that we do not
know what is the cause of this process. If we rule the
pure oxidation theory as out of court there then remain
the enzyme theory and the micro-organism theory. The
former as propounded by Dr. Mann—that fermentation
is caused by a soluble ferment or enzyme which exists
in the cells of the leaf, and which on being set free
during rolling causes the oxidation of the tannin. The
latter was advocated about two years ago by Dr. C. L.
“Bernard, of Java, who claimed that fermentation is
caused by soluble enzymes which do not exist in the
cells of the leaf but in those of micro-organisms. Much
the same uncertainty is attached to practically every
branch of tea manufacture. It is surprising that a
Scientific Department was not created many years ago.
If such had been the case we should probably now be
‘groping in the dark” to a,much less extent than we
are.—H. H. S. ;
1S, Sawamura. Ibid., 5 (1902-3), p. 237.

48 The Fermentation of Cacao

exclusively to a change of cacao red. If the
production of the colour is due to an incom-
plete oxidation of the tannin, then there will
be less tannin found in the cured cacao than
in the fresh cacao. This agrees, indeed,
with some analytical ‘determinations of Prof.
Harrison, published by Hart.'. The fat con-
tent is assumed not to change during the curing
process, and this is in all probability the case.
The data compiled under this condition are as
follows for Calabacillo cacao :—

ANALYSES OF CALABACILLO Cacao.

Gansiitizent fue, poe.
Fat... as wa 20°25 xs 219125
Tannin... — we 500. 36
Cacao red ees wae BOG es, = 130)
Theobromin ... ae If95 .: Too
Caffein ... ete .. OID 1... 0°03
Starch .. in fae YO san, “BtB2
Glucose vs v= O'0.-—si«wu“s——s«60
Hemicelluloses | wee SUID e374
Woody fibre ... i 3103 ae = 7B
Protein “9 = GQ. 44g
Amido compounds we OF53 2°06

A part of the changes oe about by
curing is probably due to the action of the
living cells in the seed, before they are killed
by the rising temperature. This would
account for the decrease of starch, glucose,
and hemicelluloses, which may be consumed
by the respiration process, but the other

1“ Cacao.”’ Trinidad, 1900, 2nd ed., p. 100,

Dr. Oscar Loew 49

changes are due to several enzymes. A proteo-
lytic enzymebrings on the decrease of protein
and the corresponding increase of amido-com-
pounds, while oxidizing: enzymes, generally
liberated from the protoplasm upon its death,
cause the decrease of tannin and cacao red
and their change to other compounds. The
most conspicuous changes are, therefore, only
possible after the death of the protoplasm,
which is a desirable factor. Hence, it is a
mistaken idea of Zipperer that the changes
are due to a germination process of the seeds.
He has even attributed the rise in temperature
of the fermenting pulp cacao to this process,
considering it analogous. to the behaviour of
barley on the malting floor. This error can
only be explained by the fact that he has never
witnessed the fermentation of cacao or coffee ;
for germination changes are not in the least
apparent.

Another result is the change of flavour. In
the fresh state the seeds have a raw, bitter,
and astringent flavour, while after fermenta-
tion and drying the bitter and disagreeable
taste has entirely disappeared. This change
is doubtless due in a certain measure to the
decrease of tannin; that is, to its change by
oxidation to a brown substance, as in the case
of the persimmon fruits, mentioned on p. 47."

1 The opinion of Harrison already mentioned, that the
decrease of the astringent taste is due to a hydrolysis, is
erroneous and would be without analogy.

4

50 The Fermentation of Cacao

The flavour of the fermented beans is still far
different from that of the prepared cacao pro-
duct, which is produced by roasting the fer-
menting beans ; hence a part of the taste must
be due to changes caused by the heat of the
roasting process, :

The presence of oxidizing enzymes in the
seeds of cacao can be proved by the usual
reaction. Upon moistening a freshly cut
section of cacao seed with tincture of guaiacum'
resin, just after taking the seed from the ripe
fruit, a blue colour is rapidly produced, first
and most intensely in the chalaza of the embryo
and gradually spreading over the entire seed
tissue; the placenta, also, soon shows an intense
blue colour. When a cross section through
the whole fruit is moistened with guaiacum
tincture, the chalaza of the embryo and the
interior soft stratum of the fruit shell become
rapidly and intensely blue, then follow in order
the colouration of the convolutions of the
cotyledons of the seed and the tissue of the
hard outer shell. Finally the whole surface
of the sections of the seed and the exposed
tissue of the testa become blue; but the slime
tissue or pulp around the testa remains perfectly
colourless, presenting a most striking contrast.

If the tissue of the seed is crushed with some
water in a mortar, the filtered liquid will show
no blue colouration on addition of guaiacum
tincture and shaking with air, while the un-

. Lignum vite —H.H.S.

Dr. Oscar Loew 51

filtered liquid will become blue very soon.
This shows an exceptional case, namely, that
the oxidase (laccase) is present in an insoluble
state and perhaps held in combination with an
insoluble protein." Upon standing, the blue
colour, obtained with the unfiltered liquid, will
gradually disappear, except on the surface, but
on adding a few more drops of the reagent
and shaking, the intense blue colour reappears.
This phenomenon is due to the presence of a
reducing compound in the juice.

In testing for a second oxidizing enzyme, the
peroxidase, the tissue of the seed, crushed
with a little water, was heated for five minutes
to 75° C. and one portion of this liquid was
filtered ; the other not. The test with guaia-
cum tincture yielded no blue reaction in either
liquid, proving that the oxidase was killed,
while on addition of a little peroxide of
hydrogen the unfiltered juice gave an intense
blue reaction and the filtered juice showed
only a trace. This difference proves that the
peroxidase, like the oxidase, was present, but
retained as an insoluble compound—an ex-
ceptional case.

Reactions with guaiacol were also tried.
This substance produced no colouration when
applied by itself, but in conjunction with
hydrogen peroxide a red colour turning to
brown was soon produced in both the hard

1 This recalls the existence of a soluble and insoluble
form of catalase.

52 The Fermentation of Cacao

as well as the soft layer of the fruit shell.
Later, in the testa and the seed generally, as
well as in the slime tissue covering the testa,
a reddish colouration was produced, but only a
weak one. This peroxidase reaction agrees
also with that just mentioned, in so far as the
slime tissue gave only an exceptionally weak
reaction compared with all other parts of the
fruit. The slime tissue of the coffee fruit is
also poorer in oxidase and peroxidase than the
other tissues.

The further generation of the characteristic
aroma of cacao is of great importance. Is
this process due to the action of an oxidizing
enzyme or to that of a hydrolizing enzyme, and
does the fermentation influence the generation
of aroma only indirectly by the development
of heat or directly by furnishing some com-
pound? Or, is the roasting of the fermented
cacao beans alone responsible for the aroma?
The investigations thus far made do not solve
this problem satisfactorily. It may be men-
tioned, however, that Hart’ agrees with Chit-
tenden,” who declared that after a certain stage
of the fermentation ‘‘ the cotyledons are found
separated and the vinous liquor of the pulp,
which passes through the membranous cover-
ing, occupies this space as well as the cavities
between the convolutions. . . . This it is
which has so marked a physiological influence

1 « Cacao.” Trinidad, 1goo, 2nd ed., p. 38.
2 Agr. Record. Trinidad, and ed. (1890), p. 110.

Dr. Oscar Loew 53

on the bean and affects its flavour, the bean
being, as may be said, ‘stewed in its own
juice.’”

According to the laws of osmosis some acetic
acid and some alcohol from the fermenting
liquor will doubtless enter through the testa
and come in contact with the cotyledons, which
thereby may be killed, if the temperature of
the fermenting mass has not already accom-
plished this. The reaction of the cotyledons
after drying the fermented beans is acid, but
whether this is wholly due to the entering
acetic acid may be doubtful, since the reaction
is weakly acid in the fresh state. A stronger
acid reaction is shown by the slime tissue.

The expression “stewed in its own juice”
used by Chittenden can hardly be admitted,
since the juice of the pulp, after being entirely
decomposed by yeast and bacteria, is certainly
not the ‘‘own juice” of the cotyledons. Still,
that author attributes to it the generation of
the flavour,

The opinion of Prof. Harrison (see p. 36)
that the decrease of tannin during the fermen-
tation process stands in relation to the develop-
ment of the aroma (see p. 37) is certainly far
from the mark, as tannin cannot produce
ethereal oils by any oxidation or fermenting
process. Only colour and taste stand in this
relation to the tannin content.

Several experiments were made by the
writer with an aqueous solution of 1 to 4 per

54 The Fermentation of Cacao

cent. acetic acid containing from 3 to 5 per
cent. of alcohol in order to imitate the com-
position of the fermenting pulp juice. After
twenty to thirty hours’ digestion of pulped cacao
at 40° to 44° C. it was observed that the pulp
had died and shrunk to skinny masses, partly
separating in small pieces, but mostly still
firmly adhering to the testa. It appears that
for bringing about an easy separation of the
dead pulp from the testa a bacterial enzyme is
necessary, as in the case of coffee fermenta-
tion. It was further observed that the amount
of acetic acid, which entered by osmosis
through.the testa to the cotyledons, was not
sufficient to kill the oxidizing enzyme, since the
freshly cut surface of these seeds rapidly turned
brown on exposure to the air. On the other
hand, it was observed that when the freshly
cut surface of the seeds so treated was moist-
ened with 4 per cent. acetic acid no further
change by oxidation took place. In this case
the oxidizing enzyme was killed.

It is stated by Hart’ that ‘of late years
there has been a large amount of inquiry for
cacao which is but slightly fermented or not
fermented at all.” This renders it very pro-
bable that the decomposed juice of the slime
tissue is not required for the generation of the
aroma, as was supposed. Indeed, the true
aroma of cacao is faint before roasting the
fermented beans. The case is, therefore,

'«Cacao.”’ Trinidad, 1900, 2nd ed., p. 33.

Dr. Oscar Loew as

similar to that of coffee, and-is different from
that of tea. With tea the aroma is the result
of the action of a hydrolizing enzyme, yielding
the volatile tea oil, as was shown by Katayama.

That the aroma of the cacao is chiefly pro-
duced during the gentle roasting process is the
opinion of manufacturers of chocolate from the
fermented beans. The fermentation seems,:
indeed, to have nothing at all to do with the
production of aroma. Seeds simply dried in
the sun and then gently roasted may yield
an especially rich and aromatic chocolate, as‘
Safford’ has also indicated. Hart says:

“No adulterdtion . . . is equal to the
flavour of the virgin cacao, provided the
essential oil has not been destroyed during
the process of roasting, during which process
it appears to be developed.”

The question now arises: which compound
yields the aroma in the cautious roasting of
the fermented cacao beans? It is certainly
not a glucoside, for neither the testa nor the
cotyledons of the beans develop anything like
a cacao flavour upon being boiled for some
time with dilute sulphuric acid (3 to 6 per cent.).
The same negative result was obtained by

1 Compare the quotation in the introductory remarks
to this article on p. 34.

2 ¢ Cacao.” Trinidad, 1900, 2nd ed., p. 111. These
words, however, contradict his previous opinion already
quoted in regard to the influence of fermentation on:
aroma.

56 The Fermentation of Cacao

boiling those materials with moderately con-
centrated solution of caustic potash. It seems
probable that it is a certain concomitant of the
fat which causes the production of the flavour,
after being moderately oxidized during the
drying of the beans. Only seeds in which
the oxidizing enzymes have produced changes
can yield the true aroma by roasting, not the
fresh beans.’

In the manufacture of the cacao powder of
commerce the f&t of the beans is more or less
removed, since a suitable powder cannot other-
wise be obtained, but in the direct manufacture
of chocolate this removal of the cacao fat can-
not be justified. It is claimed that cacao fat or
cacao butter is difficult of digestion, but in
reality cacao butter is as easily digestible as
cow’s butter. Besides, the removal of fat also
diminishes the aroma of the chocolate. In the
manufacture of chocolate in Porto Rico, fer-
mented cacao seeds are placed in a small
baker’s oven for about one hour, until the testa
have become very brittle and can be easily
removed. This roasting temperature is kept
considerably lower than that required for

1 Fresh beans were crushed, washed with alcohol, and
the oil extracted with ether. Neither the extracted fat
nor the seed powder developed on moderate heating any
flavour resembling that of cacao; only the alcoholic
extract yielded thus a very faint flavour of cacao. On
evaporation of the alcoholic extract another aromatic
odour is noticed.

Dr. Oscar Loew 57

baking bread. The cacao butter is not re-
moved in Porto Rico, and therefore the
chocolate manufactured there has an exquisitely
fine aroma.*

SuMMAaRY.

The fermentation process itself is due in the
first place to yeast cells, which multiply rapidly
in the saccharine juice oozing from the pulped
cacao, and produce alcohol and carbon dioxide.
In the second place bacteria patticipate, which
develop rapidly after a certain time, and change
the alcohol formed by the yeast by oxidation,
either wholly or partly, into acetic acid. These
processes cause a rise of temperature, and the
death of the cells of the seed and slime tissue,
whereby the juice of the slime tissue can
separate and, more or less altered, collect at
the bottom of the receptacles, together with
the acetic acid produced. ~

The chief object of the fermentation is to
kill and shrink the slime tissue or pulp attached
to the testa of the seed, allowing the remnants
either to be washed away, as is done in Ceylon,
or dried upon the seed, forming an irregular
brown film upon the testa. The advantage of
thus changing the voluminous slime tissue lies
in the increased facility of quickly drying the

1 | think it will be generally agreed that the English
term “chocolate” denotes an article for eating rather
than drinking, and in that case not only is all the
natural fat or butter left in the beans, but even extra
butter is added at times, I believe.—H. H. S.

58 The Fermentation of Cacao

seed. In this regard there exists a close
analogy to the fermentation of coffee. The
loosening of the adhesion between the seed and
its envelope, and the hardening of this enve-
lope (testa), are claimed as further effects of
fermentation.

The fermentation has also an indirect in-
fluence on changes going on within the seed,
inasmuch as by the temperature produced
(40° to 50° C.) the cells of the seeds are killed,
thus liberating the oxidizing enzymes, which
cause the formation of the brown colour, by
oxidation of the tannin of the seed. This
brown colouration is increased during the drying
process, and finally by the roasting.

The taste of the raw cacao bean is not only
altered by the partial oxidation of tannin during
the fermentation or sun drying of the seed, but
also by products of roasting.

The action of oxidizing enzymes, as well as
the final roasting process, plays a part in the
development of the aroma.

The Fermentation of Coffee.

The so-called fermentation of coffee has thus
far not been investigated, and has been defined
sometimes as an “alcoholic fermentation neces-
sary to remove the saccharine matter.”* Such
saccharine matter, however, should be easily
removable by simply washing with water,

' Cf. Watt, “‘ Dictionary of the Economic Products of
India.” Calcutta, 1889, vol. ii, p. 476.

Dr. Oscar Loew 59

Upon close examination the writer concluded
that the aim of the ‘ fermentation” is the
removal of a slimy stratum firmly adhering to
the parchment envelope of the seeds. The
removal of this is necessary, because the drying
of the seed envelope would otherwise be very
much retarded, and because a bad flavour may
finally be imparted to the seeds by the partial
decay of the slimy stratum during the drying
process. The process will be explained by

Fic. 2.—Structure of coffee fruit: P, pulp ; SL, slimy layer ;
Pa, parchment envelope; Si., seed with silver skin.

examining the anatomical structure of the fruit
(fig. 2).

Just below the skin of the fruit and extend-
ing between the enveloped seeds is a. fibrous
tissue containing a sweet juice. This pulp,
together with the skin, is easily separated by
mechanical means from the seeds, which are
enveloped in a hard parchment. Adhering to
this parchment is a stratum of very slimy cells,
the slime layer.

60 The Fermentation of Cacao

The preparation of coffee for market requires
the following manipulations :

(t) Pulping to secure removal of the skin
with the adhering tissue.

(2) Fermentation to separate the slimy layer
from the parchment envelope.

(3) Washing away the loosened slime.

(4) Drying “the envelope around the seeds,
to prepare for and obtain the brittleness heces-
sary for the next operation.

(5) Hulling or milling, consisting in the
removal of the parchment envelope, with
subsequent. subjection to a fan to blow away
particles of parchment envelope and silver
skin.

The entire fruit is often called ‘cherry ”
from the similarity of form and colour. The
expression ‘“‘pulped coffee” signifies seeds in
the parchment envelope with slimy layer.
“Coffee in parchment” means the product
after pulping, fermenting, and drying. The
“bean” means the seeds deprived of parch-
ment and silver skin.

Fruits of red or yellow colour should be
picked for pulping, as only such furnish seeds
of the desired bluish-green colour. Green
unripened fruit containing a hard pulp and
little or no sugar should be excluded, but such
fruit cannot be entirely avoided, since some
unripened seeds will drop off in gathering the
ripened ones.

The fruits are well moistened with water

Dr. Oscar Loew 61

when passing through the pulper, which easily
separates the skin and fibrous layer. Attached
to the pulper is a conical sieve (‘‘ séparateur ”)
placed in a horizontal position, which retains
the fruits which have accidentally escaped
pulping, and they are carried back to the
pulper.'

In order to understand the fermentation
process it must be remembered that on the
surface of all sweet fruits are a great many
yeast cells and bacteria. When, by pulping,
the sweet juice is forced out and spread all
over the separated skin, and over the pulped
coffee, it is not surprising that these organisms
develop rapidly. The sweet juice not only
contains sugar, but also some nitrogenous and
mineral matters required for the development
of organisms..,

- An examination of the skin with a high
magnifying power, several hours after pulping,
shows numerous cells of Saccharomyces, which.

1 It has been proposed to dry the pulp and bring it
into commerce as a cheap substitute for coffee. When
well pressed to remove the caffein and then mixed with
molasses, it might serve as a food for hogs. ,Greshoft
holds that its best use would be as a manure and gives
the following composition in the air-dry state:

Per cent.

Caffein ... eh oi ie cr we ET
Carbohydrates ... ws ake ea vin 123°3
Albumin 3 io es nee ry ia)
Cellulose say vn 28h vs 16°I
Water... as he ales He we 14'9
Fat see gine a es we 393
Ash 6°9

62 The Fermentation of Cacao

in form resemble chiefly Saccharomyces ellip-
sotdeus and sometimes also S. aficulatus (see
p. 41, ve ‘Cacao Ferments ”)..

Numerous bacteria are also present.
Alcoholic fermentation can soon be detected
by the vinous odour, and the fact that the
fermentation produces heat explains why the
temperature of such a heap of pulp rises con-
‘siderably after a time. A heap of nearly 30
cm. in height showed after sixteen hours a
temperature of 41°C. at an air temperature of
26°C.s Later, acetic acid is formed and the
red colour of the skin is changed to a brownish
one.

When the pulped coffee, on the other hand,
is examined, few yeast cells and bacteria are
noticed on the slimy stratum after one hour,
while after sixteen hours an immense increase
has taken place and not only is considerable
alcohol formed by the yeast cells, but also
acetic acid by certain bacteria. Mycoderma
and the mycelium of fungi are occasionally
seen. Litmus is reddened intensely and the
odour of acetic acid is readily discernible. At
the same time another volatile product is
formed in small quantity, which modifies
somewhat the acid odour.

The alcoholic fermentation of the sugar
adhering to the slimy stratum, as well as the
further oxidation-of the alcoho! to acetic acid,
and finally the respiration process carried-on
with considerable intensity by all these

Dr. Oscar Loew 5

organisms, cause a rise of temperature depend-
ing upon the depth of the stratum and the
temperature of the surrounding air. The
heaps of pulped coffee are generally 1 to 2 ft.
high. In such heaps the temperature was
found after fifteen to sixteen hours to range
from 34° to 42° C. at an air temperature ‘of
25° to 29°C.

The alcoholic and acetic fermentations pro-
ceeding in the heaps of pulped coffee are,
however, not the most essential phenomena ;
the most important point is that the .slimy
stratum is separated. from the parchment
envelope. It is by no means _ dissolved,
but merely loses its firm adhesion and’ is
left loosely spread. upon the parchment coffee
so that it can easily be washed away by a
current of water and the parchment coffee
dried.

Neither the acetic acid nor the enzyme
already present in the slime causes the separa-
tion of the slime layer, as tests have shown.

Freshly pulped coffee was kept in dilute
acetic acid (about 1 per cent. } at 35° to 40° C.
and another portion in some water containing
a few drops of ether to prevent bacterial
growth. In both cases the slimy layer was
found still firmly attached to the parchment
after twenty-four hours. This leaves no other
inference but that a peculiar enzyme dissolving
the adhesive substance (a carbohydrate ?)
between the parchment and the slimy stratum

64 The Fermentation of Cacao

was furnished by the bacterial growth, or, what
is less probable, by the yeast cells.

The “fermentation ” should not take longer
in Porto Rico than fifteen to twenty hours,
while in some sections of Central America, as
Guatemala, it must be carried on for two days!

Undue prolongation of the fermentation must
be avoided, as otherwise a brown colouration
of the parchment and of the seeds is produced,
and the seeds would further acquire a disagree-
able odour—two circumstances which render
the product unfit for market.

After the fermentation and washing, the
parchment coffee is readily dried, either on
cement floors exposed to sun and air, or better
in rotating cylinders through which warm air
passes. At a certain degree of dryness the
parchment becomes brittle and breaks easily
in the milling process, which thus removes the
parchment envelope and silver skin from the
seeds. In fact the milling must be done
while the parchment is still warm.

This milling is in many cases done in
London and not in the country where the
coffee is produced. Better preservation of
the shape and colour of the bean has been

' When carrying out these investigations Dr. Loew
was Physiologist: to the Porto Rico Agricultural Ex-
periment Station, and this essay or report was first
published in the Annual Report for 1907 of that station,
and afterwards reprinted separately, as pamphlet 1093
by the U.S. Dept. of Agriculture.

Dr. Oscar Loew 65

observed when the latter is protected for a
time by the parchment envelope. The cost of
transportation is in this case a little higher,
but it does not come into consideration, as
from $2 to $3 more has been realized per
hundredweight for coffee thus treated, than for
that cleaned in Central America. j

In reviewing the so-called fermentation of
coffee the conclusion is inevitable that alcoholic
and acetic fermentations are not of direct
benefit, but only indirect, inasmuch as heat is
thereby produced which supports the action of
a body (enzyme) furnished by the bacteria,
which dissolves the adhesive substance between
the parchment envelope and slimy layer.

66

CHAPTER III.
By Dr. FICKENDEY.

Ir was originally intended to follow up the
question of cacao fermentation to its final
conclusion before publishing any report on
what had been done towards that end. As,
however, the investigations and experiments
carried out so far have yielded results likely
to be of use to planters and others if tried on
a commercial scale, | feel justified in publishing
the following details, without waiting for the
final conclusions to be arrived at.

When preparing green cacao (z.¢., the beans
as taken from the pods), two different pro-
cesses are necessary, and must be distinctly
recognized by those having to carry out the
operation of turning such beans into the cacao
of commerce. On the one hand, there is the
fermentation of the pulp which surrounds the
beans—that slimy, sugary’ mass in which
the beans are embedded in the pods; whilst,
on the other ‘hand, we have those processes
which go on inside of and affect. the bean
itself, and which, on the whole, are only
indirectly caused by agencies arising as one

Dr. Fickendey 67

of the results of fermentation. In fermenting
the beans, the chief aim is to kill the germ
each one contains but to kill it in such a way
that the enzymes! present are not destroyed
at the same time.

This statement is confirmed by the fact that
the most important changes—which manifest
themselves after fermentation has taken place,
both to the eye in the brown colouration of the
cotyledons, and to the palate in the reduction
of the bitter taste so well known in unfermented
beans—can also be obtained without ferment-
ing the cacao by killing the germs in the beans
in such a way as not to render the enzymes
less efficient. This can be done by the use

1 These enzymes are organic catalyzers. By a
catalyzer is understood a substance which is able,
through its mere presence, and without the substance
itself undergoing any alteration, to alter the rapidity of
the chemical changes that the beans undergo, and in
most cases to quicken them. These organic catalyzers,
known as enzymes, differ from inorganic ones in that
they are more individualized, that is to say, each
enzyme is only able to influence one quite definite
process, as, for instance, the diastase known in distilling,
which brings about the conversion of starch into
sugar. Inorganic catalyzers, on the other hand, as, for
instance, finely-divided platinum, used in the self-
ignition of gas lamps, are able to influence a whole
series of widely different processes. These enzymes, in
their behaviour, 7.¢., in the effect they have on surround-
ing substances, are similar to albuminous bodies. They
are soluble in water, and lose their efficiency if the
watery solution is heated to a temperature approaching
the coagulation temperature of albumen.

68 The Fermentation of Cacao

of 96 per cent. alcohol, in which the beans,
after all the pulp surrounding them has been
carefully removed, are laid for ten minutes, and
then left for four or five days suspended over
the alcohol. After this they must be laid for
one minute in ,water, and then dried. The
germs can also be killed by freezing if the
beans, placed in a glass vessel filled with
water, are exposed to the influence of a freez-
ing apparatus. In both cases it is with the
access of air that the cotyledons in the bean
gradually turn brown and, at the same time,
lose their bitter taste ; but such beans differ
from those that have been fermented in one
point, viz., in the aroma. This is but natural,
and could not be otherwise, as the fermenting
process causes all sorts of substances to pene-
trate into the beans, and these affect the taste
and aroma, beneficially or otherwise. Never-
theless the beans so treated (ze, placed in
alcohol or under the influence of freezing
water) still have the recognized chocolate
flavour. :

The browning of the cotyledons and the
removal of the bitter taste are in the relation
of cause and effect. The bitter taste is to
be attributed to the presence of substances
containing. tannin, and the brown colouring
is due to the changes that the beans undergo
on account of the oxidation of these tannic
substances. If a bean is cut through, the
exposed surface turns brown, which peculiarity

Dr, Fickendey 69 ,

is generally to be met with in fruits containing
tannic substances, as, for instance, in apples,
in which the colour or discolouration that results

DR. FICKENDEY, AGRICULTURAL DEPARTMENT.
CAMEROONS, GERMAN WEST AFRICA.

from being cut is caused by the oxidation of

the tannic substances in the fruit. The query
as to whether a kind of leathery formation

70 The Fermentation of Cacao

results at the same time, has still to be decided,
but that is outside the present discussion. :

The cotyledons also turn brown, and the
bitter taste is removed if the green cacao, freed
from the surrounding pulp, is ground into a
pulp or jelly. This treatment also kills the
germs, but leaves the enzymes intact. At
this point it will not be out of the way to
compare the behaviour of the sloe (Prunus
spinosa), which has a strong resemblance to
cacao in certain points. Left to itself the sloe
‘has such a bitter taste that it is unfit to eat,
but after a frost the pulp cells die off and the
enzymes make their action felt, with the result
that the acidity disappears, and the fruit
becomes palatable. Here, again, the reduc-
tion and final disappearance of the acidity
is also accompanied by the appearance of a
brown colouration which is likewise caused by
the oxidation of the tannic: contents (perhaps
after. a previous separation of the glucoside).
The supposition that an oxydase plays a part
in bringing about the fermentation of cacao
beans (by an oxydase is meant an enzyme
which hastens oxidation) has been stated more
than once, and that it is so can be easily
proved. The oxidation of the tannic sub-
stances in other fruits containing tannin is
attributed to the assistance of oxydases. If
cacao beans are heated in water at 75° C. and
then ground, no change of colour and no
reduction in the bitter taste of the mass takes

Dr. Fickendey 71

place, whilst the bluish-red colour remains.
This, after an hour's heating at 70° C., changes
to brown. The beans themselves can be
made to turn brown if warmed to’ 75° C.
and a small quantity of watery -extract from
some fresh beans is mixed in the pulp. As
a comparative experiment to this, take
another lot of beans and mix them with
some of the extract which has been pre-
viously warmed from 80° to 100°C. ; it will
then be seen that no brown colouring results.
This watery extract, which also. contains
the enzyme, is obtained by grinding fresh
beans with cold water, afterwards filtering
off the liquor. The resultant extract is
coloured brown. Again, if the cacao pulp
from heated beans is kept with the extract
from fresh beans in glass vessels with only a
small surface exposed, it will be noticed that
the browning first sets in on the surface and
penetrates downwards in proportion to the
ability of the air to likewise enter the mass.
Even if the beans be boiled in water the
tannins enter into solution. This solution also
turns brown, owing to oxidation, if a small
quantity of the above-mentioned extract is
mixed with it. Even a purified solution of
tannin (obtained by precipitation by acetate
of lead, filtering off the liquor, and separating
the lead compounds by means of sulphuretted
hydrogen), to which some of the extract has
been added, also causes the brown colouration

72 The Fermentation of Cacao

to set in again from the surface downwards.
All these results will probably lead to the
acknowledgment that an oxydase assists in
producing the brown colouration of the beans,
and that this is brought about by the oxidation
of the tannic substances. Whether a decom-
position of the glucosides takes place prior
to oxidation has still to be investigated and
ascertained. The behaviour of beans with a
whitish break, z.e., Criollo beans, differs from
the beans having purple cotyledons, z.¢., of the
Forastero. variety, inasmuch as the devitalizing
temperature is 5° to 10° higher (for Criollo
beans), but in other respects the conditions
are the same. Here, again, we have the same
tannic substances formed in the white cells,
as can be proved if sections of the beans are
examined. Under the -microscope the cells
containing the tannic substances can be
distinguished in the purple (Forastero) beans,
on account of the purple-coloured matter
they contain, which matter also is of a tannic
character.

Comparing the results of all these experi-
ments led to the discovery that the oxida-
tion of tannic substances increases very quickly
in weak alkaline and neutral reaction, and that,
on the other hand, with an increased propor-
tion. of .acid, the influence of the oxydase
diminishes to a corresponding degree. The
concentration of the acid which is noticeable
in the pulp (some yy to 2 normal) causes,

Dr, Fickendey "8

already, a considerable reduction in the oxida-
tion process. As in the case when fermenting
the pulp, acid is again formed but of a more
concentrated nature, the percentage of acid,
when the work is carried out on a commercial
basis, being increased. From the above facts,
when carrying out these operations on a com-
mercial scale, one has to note first of all that
the temperature must not be raised above 65°
to 70° when drying the beans, and I am nearly
certain that the cacao can be dried without
exceeding that temperature. As the beans
continue to attract moisture after being dried,
the enzymes can still develop their activities
and further improve the quality of the cacao
whilst in warehouse or being transported ; but
otherwise (z.e., if the temperature is raised) the
enzymes run the risk of being killed. Further
experiments resulted in the proposal to pass
the beans through a potash solution after being
fully fermented, but previous to being dried.
Doing so, whilst offering no practical diffi-
culties, promises to offer the following advan-
tages :—

(1) The addition of potash reduces the
acidity in the cacao.

(2) This reduced acidity increases the activi-
ties of the enzymes, enabling them to act more
freely, and the beans to be freer from bitter-
ness.

(3) Cacao cured in this manner should,
when manufactured, become more soluble, and

74 The Fermentation of Cacao

show greater capabilities of suspension in the
cup. On this point I may remind my readers
that in some manufactories the cacao, after
roasting, is treated with potash.

Experimental trials have shown that the
advantages claimed from experiments Nos. 1
and 2 have been realized; but whether there
is also a greater solubility and capability of
suspension in the- manufactured article must
be left for the maker to find out.

In conclusion, I would add that it is highly
desirable that some of the estates should
arrange to carry out the experiments described
on a large scale and so prove their advantages,
or otherwise, on a commercial] basis ; and this
can be done in the following manner :—

After being fermented, ‘place the beans in
bags or baskets,’ and steep them in a potash
solution, containing between 5 and Io per cent.
potash, for ten minutes, taking care that the
liquor comes into contact with all the beans to
an equal extent®; now run off the liquor, and
dry the beans in the usual way. The cost
of such a treatment is not heavy, and experi-
mental shipments will soon show whether the
increased prices obtained pay for the extra
trouble and cost incurred ; otherwise to form

1 J would suggest baskets, as used in Ceylon and
elsewhere, when the beans are washed by dipping and
holding the baskets in running water. See Dr. Axel
Preyer’s essay, p. 11—H. H. Ss.

2 This can bé assured by gently shaking, or otherwise
agitating, the baskets of beans.—H. H. S.

Dr. Fickendey ‘ 75

an opinion without making a series of ship-
ments sufficiently long to thoroughly test the
market, and to enable the makers to decide
whether or not the beans prepared in the
manner described are preferable, is most diffi-
cult, for the cacao market depends almost
entirely on the whim of the public, and the
style of cacao and chocolate called for at the
time being.

77

76

CHAPTER IV.
By Dr, A. SCHULTE IM HOFE.

In which 1s included some Comparative Notes
on the Fermentation of Indigo, Tea, Coffee,
and Tobacco.

[NoTE By Dr. RONALD KROHN, THE TRANSLATOR,
—There are some German technical terms used in
this section that I cannot find the exact equivalent
for. In one or two instances there are errors,
possibly overlooked during proof-reading, which I
have corrected as far as possible.

Page 77, line 16: From “that the process .. .
- indigo.” As the German original stands the passage
cannot be understood, but I am certain from the
context that I have given the author’s meaning.

Page 81, line 25: ‘“ Kernel.” The German is
“ Kern ” and may be rendered kernel, cotyledons
or nucleus.

Page 95, line 12 (and elsewhere): “Tray.” The
German is “ Horde,” literally “hurdle,” but I have
used the technical term “ tray.” ;

Page 105, line 26 (and elsewhere) : “ Fermenta-
tion floors.” The German is “ Tennen Fermenta-
tion.” ‘Tenne”’ is a floor and is used in malting
as well. The technical term in the case of cacao
may be different.

Page 113 :, “Tunnel drying,’ German “ Kanal
trocknen,” ffom the description I should have

Dr. A. Schulte im Hofe . 79

thought the German word “Gang” would be better,

i.e., “ Passage,” but here again there probably is
some technical term, and I believe “tunnel” is
best. ]

Wuen I was in British India some seven-
teen years ago, | turned my attention to the
study of indigo fermentation, believing that
the experience I had gained in the sphere of
industrially applied fermentation would prove
of particular value to me. From all that I
had read and heard about the manufacture of
indigo, I had come to the conclusion that
micro-organisms played an important réle in
the production of indigo from J/xdigofera
tinctorta, but I was very soon able to prove,
however, that the process known as ‘“ ferment-
ation” in the manufacture of indigo has
nothing to\do with the formation of com-
mercial indigo, and that, in fact, the latter
can be obtained from the plants even
when the fermentation process is_ entirely
omitted, because, as a matter of fact, the
formation of indigo depends on a process of
oxidation.’

When, some years later, I took up the study

1 Dr. A. Schulte im Hofe: ‘“ Indigokultur und
Fabrikation in Britisch Indien,”’ Dev Tvopenpflanzer, 1902,
pp. 70 to 128. * Studien uber den Gehalt der Indigofera
tinctoria au Indican, sowie iiber die Gewinnung des
Indigo.” ‘Berichte der Deutschen Pharmazeutischen
Gesellschaft,’’ 1902, p. 19.

78 The Fermentation of Cacao

of the cultivation and manufacture of tea, I
found that here again an oxidation process
constituted the essential factor in the conver-
sion of the freshly gathered green leaves into
black tea.’

Studies.in Cacao Fermentation in
the Cameroons. ‘

It was, therefore, only natural that when,
towards the end of 1899, an opportunity of
studying cacao fermentation was afforded me
in the Botanical Gardens at Victoria in the
Cameroons, I began my researches by seeking
to determine whether an ogjglation process does
not also occur in this case. Even the first
experiments confirmed my assumption, and |
found that the chemical changes that take
place in the cacao beans are precisely similar
to those that bring about the conversion of
green tea-leaves into black tea. Before enter-
ing more fully into the results of my investiga-

' Dr. A. Schulte im Hofe: ‘ Die Kultur und Fabri-
cation von Tee in Britisch Indien und Ceylon mit
Ricksicht auf den wirtschaftlichen Wert der Teekultur
fiir die deutschen Kolonien.” Der Tropenpflanzer, 1go1,
vol. ii.

? In all these experiments I have not attempted to
determine whether the oxidation is due to the action
of enzymes or not. For, in the first place, this is not
essentially important to the process. Secondly, I then
had no laboratory at my disposal, for this was only built
later in Victoria. I therefore had to limit myself to
only the most necessary apparatus and reagents which
I had brought with me.

Dr. A. Schulte im Hofe 79

tions, I shall briefly describe the main points
of importance in the treatment of tea, in order
to be better able to explain the similarity, or
rather identity, of the two processes.

Dr. SCHULTE IM HOFE.

The freshly gathered tea-leaves are spread
out in thin layers and dried until (on folding

80 The Fermentation of Cacao

the leaf) the midrib and (on compressing a
handful of leaves) the connecting stalks no
longer break, The leaves are then rolled by
a mechanical contrivance which causes an
alternating, heavy and light pressure to be
brought to bear on them in such a way that
during the application of the heavy pressure
the sap of the leaf is forced out and spréad
over the surface, to be absorbed by the leaf
again when the pressure is relieved. The
main object of rolling is to rupture the cells
of the leaf, or at least to render them more
permeable to air. The time occupied to do
this varies between one and one and a half hours
according to the nature of the leaf. Owing
to the rolling, the leaves become considerably
heated and’ simultaneously the amount of acid
and soluble astringent substances is increased.
After rolling, the resultant massed leaves are
passed through a sieve-like contrivance which
loosens them, and then exposed to oxidation
in thinner or thicker layers, varying according
to the temperature conditions. Oxidation then
proceeds rapidly, as, owing to the rolling,
access of air to the interior of the leaves is
facilitated ; the process takes from two to eight
hours, according to the temperature and nature
of the leaves. Owing to the oxidation of the
astringent substances, the green colour of the
leaves turns yellow or copper-coloured, but
before this stage is reached, the oxidation should
be stopped, otherwise the tea becomes over-

4

Dr. A, Schulte im Hofe 81

oxidized, or, as it is commonly called, over-
fermented, and thereby deteriorates in quality.
After the completion of this oxidation process,
the leaves are immediately dried, and the tea is
ready for use.

The changes occurring during the oxidation
of the tea-leaves entirely correspond, as I show
later on, with what takes place in cacao-fermen-
tation. Here the beans, having been removed
from the fruit, are packed in casks or boxes or
thrown into heaps. After a short time has
elapsed alcoholic fermentation sets in, causing
the beans. to become heated. In order that
uniform fermentation may be secured all the
beans should be equally brought into contact
with the air. To achieve this they are trans-
ferred from one box into the next, or the heaps
are well turned over with a shovel. Asa rule
acetic fermentation has already commenced to
set in on the second day, owing to which the
alcohol formed from the sugar is converted into
acetic acid. This is accompanied by a further
rise of temperature, the shell of the bean be-
comes detached (s¢z76¢ a6) from the cotyledons
and the acid penetrates into the kernel or
cotyledons. In’ the case of beans having
bluish-violet cotyledons, the colour is changed
by the action of the acid to reddish-violet.!

1Dr. A. Schulte im Hofe: “Das Wesen und der ©
Zweck der Kakao-fermentation,’’ Der Tvopenpflanzer,
1900, Pp. 227. —

6

82 The Fermentation of Cacao

The condition of the cacao beans at this stage
corresponds to that ofthe tea-leaves after
rolling, and the increased acidity of the beans
was ascertained by analysis in the same way
as was done in the tea fermentation experi-
ments.

If the term cacao fermentation be intended
to express the alcoholic and acetic fermentation,
it is certainly quite correctly applied, but this.
is not the case if it be extended to the: process
by which the reddish-violet colour of the con-
tents of the beans (z.e., the cotyledons) is.
converted into brown, and by which. the bitter
astringent substances are split up into an in-
soluble brown one anda soluble, more or less
aromatic compound. If one examines the
beans at the commencement of the drying
process (after being fermented the beans are
at once dried by various methods) one will
find the fluid that. exudes on fracturing the
skin or shell begins to turn brown, i.¢., to be
permeated by small brown particles, a sign
that oxidation has already commenced. This
has been confirmed by experiments as follows:
Freshly gathered beans, released from the husk
of the fruit, were freed mechanically from the
fleshy pulp and transferred to a diluted acetic
acid solution, until the fluid had penetrated
into their interior. During this process the
bluish-violet colour .of the nibs turned to
reddish-violet. It is even sufficient to merely
cut through a bean and moisten the cut surface

Dr. A. Schulte im Hofe 83

with acid to produce this colour reaction. The
changes brought about in the bean by alcoholic
acetic fermentation may, therefore, also be
produced by the addition of acid. Fermenta-
tion is, therefore, not absolutely essential. By
means of it, however, the acidification is brought
about in the simplest and cheapest manner,
and the fleshy pulp adherent to the beans is
more or less completely removed. The beans,
having been treated with acid, were transferred
to a flask filled with oxygen. By the action
of the oxygen the bluish-violet colour gradually
changed to brown. When the acidified beans
were broken up and then treated with oxygen,
the process took place more rapidly.

By the conversion of the bluish-violet colour
of the nibs into a brown one by means of
oxygen, it was proved that this process can
be brought about by chemical means. In the
same way I have proved that, at the same
time, as in the case of tea, the soluble astrin-
gent substances are converted into insoluble
ones. This I have already proved in the
manner described in my article on the ‘“ Culti-
vation and Manufacture of Tea in British India
and Ceylon,”?

The above experiments prove that the
oxygen in the air acts on the acidified beans
in a manner similar to that in which it acts
on the tea-leaves after rolling. Since, how-
ever, the latter are specially prepared for this

1 See Dev Tropenpflanzer, 1902, vol. ii, p. 92.

84 The Fermentation of Cacao

process by being rolled, it is natural that in
their case the oxidation process takes place
more rapidly. If the process is to correspond.
to that in tea-leaves, the cacao beans must
be ground or broken up. For practical reasons
this is, however,:impossible with cacao.

Now, if unfavourable reactions are liable
to occur even in the comparatively short time
occupied. in the process of oxidation in the
case of tea, such as too marked an acidification
and the formation of butyric acid, such changes
are still more difficult to avoid in the case of
the far more protracted process of the oxidation
of cacao. Over-acidification, the formation
of butyric acid (which produces a rancid taste,
causing a feeling of scratching on the palate),
and the development of moulds constitute,
therefore, the main difficulties in the proper
treatment of cacao beans.

Good, nay even very good results are even
now attained very often by the accidental
empirical observance of the conditions favour-
able to oxidation, On: the other hand, by the
non-observance of these rules, ze, by the
exclusion of oxidation or by over-acidifying,
&c., a large quantity of cacao is produced of
inferior quality.

A satisfactory degree of acidity was attained,
it is true, by the short period of fermenta-
tion that at first was generally allowed in the
Cameroons, but owing to the rapid subsequent
drying in the Mayfarth dryers, the oxygen

Dr. A. Schulte im Hofe 85

of the air had no opportunity of acting on
the beans, and thus a harsh, bitter and
astringent cacao was produced. The sun-
dried beans contrasted in a marked degree
with the latter, and for this reason there was
a tendency to assume that the sun-drying
method was the best; a view widely held
in other countries also. The beans, obviously,
dry far more slowly in the sun than in a
Mayfarth dryer for instance, and during the
night when the beans no longer undergo the
drying process, the oxygen is given an oppor-
tunity of acting on the cotyledons. The
temperature of the beans is, however, not a
favourable one for the process of oxidation,
and thus such a cacao still remains bitter to
the taste. The conditions are rather more
favourable when the beans are sun-dried, as
they frequently are, on stone or cement drying
floors, as then the beans are thrown together
in heaps and covered over.’ By self-heating ?
a temperature favourable .to oxidation is
thereby attained. Over-heating, butyric acid
fermentation and the development of moulds
are all avoided by the spreading out of the
beans in the sun on the following morning. If,
in consequence of rainy weather, or before the
beans are fairly dry, they have to be kept
for any length of time in heaps, further acidi-
fication as well as butyric acid formation takes

1 As at nights—H. H. S.
® When in heaps.—H. H. S.

The Fermentation of Cacao

86

‘sjivi uo unI
sjaaya pasuey ayy Moy pu ‘shvr] aq} Aq P2tdA0d vale aAISUa}Xd 94} 91ON

(ANOH], NVS) AZ] VADY LV STUAHA\ NO SAVAL NI OVOVD ONTIAYT

Dr. A. Schulte im Hofe 87

place, and the consequent moulds formed from
that cannot be avoided. Hence, according to
the weather conditions, one may obtain at one
time comparatively very good results, whilst
at another period a very bad quality of cacao
is produced. This was probably the reason
for the introduction of appliances such as
movable trays, by which the cacao could be
rapidly placed under cover when it commenced
to rain. By thus sheltering the beans the
above-mentioned drawbacks were considerably
diminished, but it was never possible to obtain
so good a cacao as was obtained by drying on
floors when favoured by several successive
days of fine weather. At the same time
mechanically dried cacao is never so bad as
that which has been subjected to several
successive rainy days.

In other countries the opinion has gained
ground that a better quality cacao could be
produced with slow drying by spreading the
cacao out in thicker layers. That such may
be the case can be easily understood from
what has been said above. The slow-drying
process gives the oxygen a longer opportunity
for acting on the beans ; further, the tempera-
ture then existing is, as a rule, more favourable
for oxidation.

My assumption that, at times, as with tea,
oxidation is favourably influenced by higher
temperatures, was also confirmed by experi-
ments conducted at the Botanical Gardens in

88 The Fermentation of Cacao

Victoria. Before the beans that had been
fermented in the ordinary manner had cooled
down after the first day of sun-drying, they
were packed into a cask and covered. On
the second day these beans, which were still
warm, over 30° C. (86° F.), were again spread
out in the sun, and before sunset again treated
in a similar manner. In one of the experiments
the cacao was damped on the third and fourth
day by sprinkling it with water in order to
prevent the drying from being too rapid, and
to give the oxygen an opportunity of acting
on the beans for a longer time at a higher -
temperature. The cacao thus obtained was
tested in Germany and found to be better
than that dried in the ordinary way.’ Estima-
tion of the soluble astringent substances con-
firmed the fact that, especially in the case of
the last experiment, the process of oxidation
was more advanced. Although this cacao did
not satisfy all the demands that might be made,
it nevertheless confirmed the correctness of
my assumption, that the oxidation of the
astringent substances is an essential point in
cacao fermentation.

I had arrived at this point in my studies,
when I returned to Germany in 1900. Before
continuing my investigations in the Tropics, I
thought it advisable to determine the most
favourable conditions for the oxidation of cacao
' by experiments conducted in Germany.

1Dr. A. Schulte im Hofe: ‘ Zur Kakao-Fermenta-
tion,’ Dey Tvopenpflanzer, 1901, p. 225.

Dr. A. Schulte im Hofe 89

Studies on Cacao Fermentation conducted in
Germany.

Dr. H. Salzmann, of Berlin, kindly placed
his laboratory, and Messrs. Theodor Hilde-
brand and Son in Berlin any quantity or
quality of cacao I might desire, at my disposal,
for the purpose of this investigation. I had
unfortunately neglected to bring some freshly
dried, unfermented beans with me. However,
I found among the different samples of cacao
some beans in which the process of oxidation
had only slightly advanced. In some of the
samples I even found beans on which acetic
ferments had not yet acted. I shall refer to
these later.

Carrying out these experiments in Germany
had the great advantage that the practical
value of the results could always be immedi-
ately tested by experts; this enabled one to
judge which direction further experiments
should take. This essential assistance was
given me by Messrs. Theodor Hildebrand
and Son.

As space prevents me from giving a detailed
account of all the extensive laboratory experi-
ments that I carried out, and the results they
yielded, I shall restrict myself to stating the
main results arrived at. In the first place, I
again proved that a higher temperature
accelerates the processof oxidation, and that the
latter takes place more rapidly at 50° to 60°C.
(122° to 140°F.) than at 30° to 4o° C. (86° to

go The Fermentation of Cacao

104° F.), but that in the latter case the cacao
assumes a better colour.

To determine what exact percentage of
moisture the beans should contain was a
difficult matter to decide. It must be clear
to anyone having even only a slight knowledge
of bacteriology, that we are here dealing with
conditions exceedingly favourable to the growth
of micro-organisms, this being particularly the
case at temperatures ranging from 30° to 50°C.
(86° to 122° F.). The object of my experiments
in this connection was, from the first, to
determine the lowest possible degree of
moisture at which oxidation was still possible ;
for, the lower the amount of water present,
the less favourable are the conditions for the
growth of micro-organisms. On the other
hand, I found that the lower the amount of
humidity, the slower the process of oxidation
became. On the plantations it is necessary to
dry the acidified cacao even if only to help
the air to obtain access to the interior
of the beans. At a percentage of humidity
amounting to 20 per cent., the conditions for
oxidation to occur were still fairly favourable,
but butyric acid fermentation and the develop-
ment of moulds still occurred very frequently.
The latter were practically excluded when
the percentage of humidity decreased to 15
per cent.

Having determined the changes taking
place in the beans by means of laboratory

Dr. A. Schulte im Hofe gl

experiments, I now: experimented with larger
quantities of cacao in the chocolate factory
of Messrs. Theodor Hildebrand and Son.
These experiments showed that butyric acid
fermentation and the development of moulds
were unavoidable when the percentage of
moisture was 20 per cent., and -hence that
oxidation must be carried out at a lower
percentage of humidity than that.

I also succeeded in these experiments, as |
had done in those conducted in the laboratory,
in reducing to a marked degree the bitter,
astringent taste so common to insufficiently
oxidized beans cured on the _ plantations,
thereby improving the flavour of the beans,
and increasing their market value.

I take this opportunity of expressing my
thanks to Mr. Dresel for his valuable assist-
ance in the experiments conducted at Messrs.:
Hildebrand’s factory, for although the object
of my experiments and investigations was in
the main to obtain practical results, these can
only be obtained when the scientist and the
practical man work hand in hand. Hence, as
was also the case in previous experiments, |
have found it necessary, when investigating
for industrial reasons into the question of
fermentation, to obtain a personal knowledge
of the practical side of the matter, and to do
this I undertook technical practical work for
some time both in breweries and distilleries.

My studies, which started in the Cameroons,

‘

92 The Fermentation of Cacao

and continued in Germany, were thus com-
pleted for the time being. By means of them
I had proved that cacao fermentation falls
into two sections; the first is the process of
alcoholic and acetic fermentation; the second
that of oxidation, the former having to precede
the latter. I do not wish to maintain that the
presence of acid is absolutely necessary for the
oxidation of the acrid substances to take place,
but that only under such circumstances can
a good, marketable cacao be produced.
Further, I proved that before starting the
oxidation process, the beans should, for
practical reasons, be partially dried, and that
by maintaining a percentage of 15 per cent.
moisture or less, the process of oxidation can
be extended over a more prolonged period
without running the risk of generating butyric
acid ferments or the development of moulds;
and further, that at higher temperatures, such
as 50° to 60°C. (122° to 140° F.), the process
of oxidation proceeds more rapidly than at
30° to 40°C. (86° to 104° F.), but that the colour
remains a better one at the lower temperature.
My next object was to apply my results in a
practical way to cacao cured on the estates.
Unfortunately the planters’in the Cameroons:
to whom I applied refused to entertain my
suggestions, and the Colonial Office also
refused to allow me to introduce this method
to the Botanical Gardens out there.

I attribute this attitude on the part of the

Dr. A. Schulte im Hofe 93

planters and the Colonial Office to the influence
of the leading members of the Committee
of Colonial Agriculture (Kolonialwirtschaft-
lichen Komitee). Apparently there was an
impression that only such questions of tropical
agriculture should be countenanced as had
obtained the approval of the Committee, and
that the least that could be done in connection
with any other investigations and endeavours
was to place difficulties in the way. Under
these circumstances I was particularly pleased
to gain the support of Mr. Monteiro de
Mendon¢a of Lisbon, the proprietor of the
well-known cacao plantation, ‘‘ Boa Entrada”
in San Thomé. Just as some years earlier,
when engaged in studying the cultivation and
manufacture of indigo and tea, I was most
kindly received by the English in India, so, on
this occasion, it was by the Portuguese. Thanks
to this I commenced work in San Thomé in
1903, and the conclusions | had arrived at as
the result of the investigations I carried out
in 1896 in the Cameroons, and continued in
Germany, were fully confirmed.

Researches on Cacao Fermentation at San Thomé.

To enable me to carry out the oxidation
process, two oxidation ‘chambers were erected
in San Thomé, fitted with a heating apparatus,
by means of which the temperature in both the
chambers, either singly or together, could,
when desired, be raised to, or maintained at,

The Fermentation of Cacao

94

‘pUIOYL, US ‘a}¥Isy BpejUW vog uo “329 ‘sasnoy-3ulkiq ‘aduapisay
‘ALVISY OVOVD AOUVT V NO SONIGTING AHL

Dr. A. Schulte im Hofe 95

any desired degree of heat. These chambers,
which were separated by a partition or wall,
measured 5°50 m. long, by 1°60 m. wide and
1°50 m. high (say 18 ft. long by. 5 ft. 3 in. wide
and 5 ft. high). From a furnace at one end
of the chambers the heated air was conducted
by pipes along the side walls through a tunnel
lying at a lower level. At the end opposite
the furnace there were folding doors, and a set
of 60 cm. (21 in.) gauge rails led into each
chamber. The chambers were each capable of
accommodating 3 trolleys, fitted with 10 trays
each, or 6 smaller trolleys with 5 trays each.
The cacao was spread out on the trays in
layers about 10 cm. (4 in.) deep, and each
chamber took about 1,500 kg. (say 14 tons)
cacao.

The fermentation was carried out by the
following method: Immediately after being
gathered, the pods were broken open and the
contents removed and subjected to an alcoholic
and acetic fermentation in boxes (see illustra-
tion, p. 36) in the usual way. This fermenta-
tion was assisted by transferring the beans each
day from one box to another. As soon as
the bluish-violet colour of the cotyledons had
turned to a reddish-violet, and the beans had
absorbed all the fluid possible, they were dried
in the sun in the usual way until they only con-
tained 15 per cent. of moisture. Then the
beans were spread on the trays in layers
10 cm. (4 in.) thick, the trays placed on the

The Fermentation of Cacao

96

(ZNOHI NVS) FSNO]Y ONILVAMS YO ONILNANAAT
HHL LV ONIAINNY ‘SAAVAT VNYNVG HLIM GAUAAOO ‘OVOVD AO SUVD

Dr. A. Schulte im Hofe 97

trolleys and the latter run into the chambers,
in which the temperature was maintained at
between 40° to 50°C. (104° to 122°F.). As
there was no great draught, the expenditure
of fue was comparatively small.

This oxidation process was allowed to
continue until the reddish-violet colour of the
beans had changed to brown. The trolleys
were then run out of the chambers and the
drying of the beans completed, which took but
a short time.

In order to ascertain whether, in the case of
the freshly gathered cacao also, there was any
disadvantage in allowing the moisture to
exceed 15 per cent., some beans containing
20 per cent. of moisture were subjected to a
precisely similar method of oxidation. Here
again, as in the case of the experiments in
Germany, the formation of moulds, &c.,
occurred ; also, when on a subsequent occa-
sion a few basketfuls of beans, with
25 per cent. of moisture, were emptied on to
one of the trays by mistake, as soon as the
oxidation process was completed, the difference
was immediately detected, for these beans were
covered with mould, whilst the others were
perfectly free of it. It is therefore evident,
that the moment one is working with beans
containing too much moisture, the fact can at
once be detected, and it thus becomes an easy
matter for the planter to determine whether
the work is being done properly or not. I

7

98 The Fermentation of Cacao

further noticed that when the oxidation process
had beer properly carried out, the beans were
covered by a delicate white éfflorescence.
This may serve as a means of recognizing
whether the cacao has been treated in the
above manner or not.

I remarked also that the time required for
the change in colour from reddish-violet to
brown varied in different beans. As is well
known, the same observation has been made
in the case of beans treated by the usual
methods. This peculiarity probably depends
on the varying degrees of maturity or ripeness
of the pods themselves, and possibly this is
the reason why some planters believe that it
is advisable to allow the fruit to coritinue
to ripen in the pod for some time after being
picked.

The flavour of each lot of cured cacao was
tested after being dried. For this purpose
tasting samples were prepared exactly in the
same manner as is done in the chocolate
factories when testing samples of caca@ to be
offered for sale. A sample of cacao was
roasted, ground, and, for want of a small rolling
machine, crushed to a fine powder in a mortar.
Exact portions of this powder were weighed
off, and boiled in definite.and equal quantities
of water, and then tested as to colour, aroma
and taste. In my first experiments I took
samples from the same batch on each day
of the oxidation process, and dried them.

Dr. A. Schulte im Hofe 99

The test showed that if the oxidation process
was prolonged until all the beans had turned
brown, the taste was less full and there was
less aroma than in samples containing some
of the reddish-violet beans mixed with the
brown. In this case again there is an analogy
with what is met with in the case of tea.
Freshly gathered tea-leaves do not form a
uniform mixture, the leaf-buds oxidize more
rapidly than the young leaves, and these again
more rapidly than the older leaves. It is impos-
sible to oxidize all the different types of leaves
separately ; and though, it is true, an attempt
is made to separate the leaf-buds by sifting
after the leaves have been rolled, and to
oxidize the two sets separately, even then a
mixture of leaves of varying ages remains.
Continue to oxidize the tea until all the leaves
turn to a yellow coppery colour, and you will
find that a large proportion would be super-
oxidized, with the result that tea so prepared
lost considerably in its fulness of flavour and
aroma, and it is for this reason that oxidation
is stopped before all the leaves have turned
yellow. After I had proved that this irregu-
larity in oxidation also occurred with cacao
beans, the process was checked as soon as the
major portion of the beans had turned brown.
It now only remains for the planter to learn
by experience when the most favourable stage
in the fermentation process has been reached,
for this stage will be found to vary according

100 The Fermentation of Cacao

to the different districts in which the cacao is
grown, the variety of beans treated, and the
method of gathering. It will, however, be
necessary for planters to test the different lots
as to taste, &c., in the same way as the tea-
planter does.

The time required for oxidation depends on
the temperature employed and the variety of
the bean to be cured. The most suitable
temperature to produce a good quality is from
40° to 45°C. (104° to 113° F.). I do not men-
tion any definite time, as I do not wish to
encourage planters to work by rule of thumb ;
the best degree of oxidation and the test by
tasting can alone determine this point. At
Boa Entrada | used to ferment the beans from
two to three days.

The essential principle underlying the
method I introduced at Boa Entrada is not
based on the oxidation chambers, but on the
fact that what is known as cacao fermentation
consists of two essentially different processes.
The first leads to the acidification of the beans,
which object is best attained by exposing the
freshly gathered beans to conditions under
which the sugar contained in the fruit pulp
adhering to the beans becomes converted
into alcohol, and the latter is then converted
into acetic acid. We must, therefore, provide
conditions favourable to alcoholic and acetic
fermentation. I shall later on show that
this can be done in a more practical manner

Dr. A. Schulte im Hofe IOI

than by the usual method of sweating boxes
at present in use.. As soon as the acétic acid
has penetrated sufficiently into the cotyledons,
fermentation should be interrupted, as other-
wise super-acidification may supervene.

The object of the second process is to
produce oxidation of the astringent substances
contained in the beans, in order to remove
the unpleasant, acrid, bitter taste, and simul-
taneously to develop the aroma, &c. Since
an increased temperature favours this process,
the beans must be warmed. Further, the
advent of air to the interior of the beans must
be facilitated ; this is achieved by drying the
latter. .

From what has been said above, it will
probably be sufficiently plain that this division
of the so-called cacao fermentation into two
sections, vzz., an alcoholic and acetic acid
fermentation and a subsequent oxidation, is
something quite new, and rests on a scientific
basis. It will also be seen that the preparation
of a good quality cacao is based on a correct
carrying out of both processes.

Some gentlemen, who visited the Boa
Entrada estate in San Thomé after I had
introduced this method of oxidizing the dried
beans at higher temperatures, criticized the
process as being empirical and too trouble-
some. This merely proves that they looked
upon the oxidation chambers erected there
as an essential part of the, method, but did

102 The Fermentation of Cacao.

not recognize the real object of them, viz., to.
bring about the oxidation of the partly dried
beans at higher temperatures. At the same
time they admitted that cacao treated by this
process was of better quality.

I have already pointed out that by the
fermentation and drying methods at present
employed, satisfactory results are obtained em-
pirically in some cases, and that quite good
cacao can be made from beans having lighter
coloured nibs or cotyledons, z.e., such as con-
tain a smaller amount of bitter substances. |
propose now to enter more fully into the
methods of gathering, fermenting, drying and
dispatching the cacao that are usually adopted
at the present time so far as they are known
to me, and shall also point out how the
method I have proposed might perhaps be
used without necessitating any great changes
being made. Finally, I shall suggest how in
starting a new plant or cacao curing installa-
tion the method of oxidation I have proposed
may best be taken into consideration.

The Gathering of the Cacao.

On smaller plantations it is possible to pick
cacao every week, and the pods will then be
found to have reached an approximately equal
stage of maturity or ripeness, but on larger
plantations this cannot be done. In practice,
therefore, one can never be in a position to
treat pods of the same degree of maturity,

Dr. A. Schulte im Hofe 103
and when the pods become over ripe the
beans start to germinate inside the husk.
They do not therefore remain at the same
stage of ripeness for any length of time, as
is the case with some other kinds of fruit.
Hence even if the beans are allowed to. con-
tinue to ripen after the pods are gathered,
as is done in some isolated cases, no uniform
product is obtained. This fact must be
allowed for just as it has to be in the case
of tea.

The Fermentation of Cacao.

On all plantations, even those worked on
the most primitive lines and owned by
natives, the beans are piled into heaps or
placed in casks, or other receptacles, or
special fermentation boxes, as soon as the
husk of -the pod has been removed. In
many cases the natives are in the habit of
leaving the beans to their own devices with-
out any mixing, or turning over when being
fermented. I have had the opportunity on
several occasions of observing in such cases
how the acetic fermentation has acted in a
satisfactory manner in the upper or outer
layers, whilst deeper down the beans have
not yet passed beyond the stage of alcoholic
fermentation, and that indeed even this has
not penetrated into the centre of the beans.
The beans thus fermented were then dried,
but it must be obvious to anybody that an

104 The Fermentation of Cacao

even sample or break cannot possibly be
obtained by such a process; you had in fact
a mere mixture of brown, violet and_ slate-
coloured beans. The latter are often described
in the trade as “unripe”; to my mind a per-
fectly false designation, for they are beans that »
have been completely excluded from fermenta-
tion. :

In all better managed plantations the beans
are turned over by being shovelled or emptied
from one box into another whilst the fermenta-
tion process is going on. In deciding when
this should be done the planter has to judge
how long should be allowed before changing
the cacao from one box to the other, whether
every day or every other day, and what tem-
perature should be maintained in the boxes;
in either case the decisions arrived at are
purely empirical.

In the Cameroons’ it was customary at first
to allow the cacao to sweat from three to
four days, but now the period has been pro-
longed. In San Thomé the methods em-
ployed are more advanced, and the period of
fermentation (or sweating) is not always regu-
lated by time, but often by the appearance of
the bean, but even here the fermentation is
usually allowed to continue too long.t

As I have already pointed out, fermentation

' I cannot altogether agree with this; at any rate the
San Thomé cacao I am in the habit of valuing does not
give me the idea of being over-fermented.—H. H. S.

Dr. A. Schulte im Hofe 105

should only be continued up to when the
bluish-violet colour of the cotyledons turns
to a reddish-violet and the bean has, by
absorption, become full of fluid. When only
slightly acidified beans are insufficiently oxi-
dized, a harsh, bitter cacao is produced, and
it was probably to render the taste milder that
longer periods of fermentation were intro-
duced; for during protracted fermentation,
especially when occurring at the higher
temperatures, oxidation takes place as well.
The beans, however, become over-acidified
and the cacao thus obtained, although milder
in flavour, has a sour taste. Should butyric
acid fermentation be added on the top of
this, then the sour taste is diminished, but the
cacao acquires a rancid flavour, becomes rough
to the palate, and darkens in colour. In both
cases the aroma is lost. By employing the
methods commonly used, therefore, unless the
conditions happen to be particularly favourable,
either a harsh and bitter,‘ or a sour or rancid
cacao is obtained.

The simplest, cheapest, and most certain
method of fermentation is that obtained by
the use of floors (¢eznen-fermentation). Here
the cacao beans are emptied on to covered
floors in layers, varying in depth according
to the temperature or weather conditions, and
turned over at least once a day. In this case

' Possibly this is what the trade calls ‘ ham-my”
cacao.—H. H. S.

106 , The Fermentation’ of Cacao

also exact directions suitable for all times
of the year and for all districts cannot be
given.

The saccharine juice contained in the fruit
pulp adhering to the outside of the beans soon
commences to undergo alcoholic fermentation
owing to the yeast cells that are naturally
distributed about them so widely, and as this
proceeds the yeast cells quickly multiply.
Should the beans only become slowly. heated,
this is almost invariably an indication that
the alcoholic fermentation is only proceeding
slowly on account of a lack of yeast cells.
Should a batch of well fermenting cacao be
at hand, the fermentation of a new batch may
be accelerated by collecting the fermenting
saccharine juice from this well fermented lot
and mixing it with the freshly gathered beans,
but this will only be necessary on very rare
occasions. A pure yeast culture is at the most
of merely theoretical interest,’ and has no influ-
ence on the quality of the cacao. After all, it
is only the amount of alcohol necessary for
acetic acid fermentation that is required, and
for this purpose the yeast cells, which as a rule
are present naturally, almost invariably suffice.

On the second or third day after the beans
have been placed to sweat, acetic fermentation
sets in, causing a further rise of temperature.
If the latter rises beyond 50° C. (122° F.), the
beans are spread in thinner layers, whilst the

1 See the other essays on this point.—H. H. S.

Dr. A. Schulte im Hofe _ 107

acetic acid formation may be increased by
using juice flowing from beans already under-
going acetic fermentation.

The work on fermentation floors resembles
that in a malt factory, except that in the case
of cacao the aim is to acidify the produce, and
higher temperatures are employed, whilst on
malting floors the barley is meant to germinate.
As during the sweating process an acid fluid
comes away from the beans, this fact must be
taken into account, as owing to it the floor
should consist of some material that is not
affected by acids, and hence cement and lime
should, as far as possible, be avoided in its
construction.’

If only small quantities of cacao have to be
dealt with, a wooden trough of suitable dimen-
sions will suffice, and the beans can be turned
about by shovelling the cacao from one end of
the trough to the other, for one end should
always be kept free, and in this way the cacao
becomes easily aerated.

At first on the plantations in the Cameroons
the cacao was washed after fermentation had
been completed, whereby the remains of fruit
pulp adhering to the beans were removed.
As, in chocolate factories, the shell is removed
from the kernel, in any case it is immaterial
whether some of the fruit pulp still adheres or

1 Wood, and especially some native woods, are far
preferable, especially as the vinegar or juice tends to
pickle and preserve it for a long time.—H. H. S.

108 The Fermentation of Cacao

not.' This fact was soon recognized, and now
the beans are not washed but generally dried .
immediately after fermeatation. Only in
isolated cases, as when working to produce a

DRYING CACAO ON TRAYS ON BOA ENTRADA ESLATE,
SAN THOME.

Note how each tier of trays runs out, one under and in
front of the other. Each of these can be pushed back
in the same way, one under the other, uhtil they reach
the roofing seen in the rear.

special quality for market, is washing’ still
practised.”
Drying the Cacao.
The process of drying may be a simple or a
complicated one, depending on the amount of

' Except that it spoils the appearance of the beans
from a selling point of view.—H. H. S.
.* Ceylon cacao is the typical growth for washed beans.
—H.H.S.

Dr. A. Schulte im Hofe 109

rain falling during the process. The most
primitive method of drying is accomplished by
spreading the beans out on small trays which
are placed in the sun during the daytime, and
brought in under cover at night or when it
rains. In prolonged rainy weather the cacao
is sometimes placed on tin sheets or metal
plates (d/echplatten) which are warmed by fire
placed underneath them, and is thus dried.
In the case of larger crops, this method would
waste too much time. Where sun-drying is
possible cement or stone floors in the open
air are used. This method is an extremely
practical one when continuously sunny weather
prevails, or, at the most, only passing showers
have to be avoided, but not when several
successive days of rain occur frequently. The
reasons why this is so I have given on p. 85.
To avoid the injurious influence of rainy
weather, and still more, to avoid the beans
having to remain in heaps for prolonged
periods when only slightly dried, large trays
were constructed to run on rails, capable of
being rapidly moved under cover when it
started to rain or at night. A further advance
was arrived at when arrangements were made
to place three or four trays one over the other.
In order that the drying process might be con-
tinued on these trays during continuously wet
weather, the shed was so constructed that the

1 [ cannot understand in such cases how the beans do
not get scorched or burnt.—H. H. S.

The Fermentation of Cacao

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Dr, A. Schulte im Hofe ITI

side walls could be easily made air-tight, and
then heat was brought to the produce from a
furnace at the other end of the shed by passing
it, z.e., the heat, through a pipe or pipes placed
under the lowest trays. Such a drying shed
was first erected in the Cameroons on the
Kriegsschiffhafen plantation. .

In other countries large stationary platforms
(known as cacao-house floors), capable of being
used for sun or artificial drying are erected.
A movable roof renders sun-drying possible,
whilst heating pipes under the floor do the
same when artificial drying is needed. A
drying-house constructed according to this, the
Trinidad (W.1.) system, is to be found in the
Botanical Gardens in the Cameroons. It has,
however, proved a complete failure owing
probably to those using it misunderstanding
some detail in the heating, or having omitted
its use. At a subsequent date drying-houses
were built on some of the estates in the
Cameroons, fitted with the movable trays to
be met with in the Trinidad drying-houses.

In cacao growing countries where the main
crop coincides with the. rainy season, sun-
drying is practically out of the question, and
artificial drying has therefore to be exclusively

1 Such a system was not considered to have proved
successful in Trinidad (W.I.), at any rate not on the
San Salvador estate, one reason being that the aper-
tures got choked up and so prevented the warm air
getting at the beans.—H. H. S.

I12 The Fermentation of Cacao

resorted to.’ In the Cameroons an attempt
was made to overcome this difficilty, first by
using the Mayfarth dryer already mentioned,
and later the Guardiola drying drums. A
serious drawback to the latter was the fact that
some kind of mechanical driving power is
required, although this is, of course, of less
importance where the drying-houses can be
constructed in such a manner that water power
may be used. A further drawback is that the
beans have to be partially dried before they
are placed in the drums or they will adhere in
clumps. A third drawback is that by the time:
the process is completed the beans are apt to
break, or at least their shells crack.?

In the early days in San Thomé, large
drying-houses, or, to be more accurate, drying-
barns, 5 to 7 m. (16 to 23 ft.) high, were
erected. Small trays, which could be easily
handled by one man, were placed in these,
one over the other, on ledges at intervals of
20 cm. (8 in.), whilst hot air from a stove was
conducted through pipes to the floor of the
barn ; but the whole method was very trouble-
some and complicated, besides which the beans

’ I must, however, point out that in the same country
the rainy periods and the amount of rainfall frequently
vary to such an extent (this is the case, for instance, in
the Cameroons and San Thomé) that sun-drying may
be quite possible in one district, at least for the greater
part of the crop, and absolutely impossible in another.

2 This is not so now, I am told, at any rate not
with the ‘“ Gordon” drier.—H. H. S.

Dr. A. Schulte im Hofe 113

dried very unevenly and the cost of fuel was
comparatively great. Probably it is for these
reasons that such drying-barns are not more
extensively used.

In 1903 the method of drying the cacao
on heated stone platforms was introduced on
several plantations in San Thomé. Heated
air from a furnace is conducted under a plat-
form 5 m. (16 ft.) long by 2 m. (6 ft. 6 in.) wide,
made with the sides raised about 25 cm. (10
in.). The cacao is dried on these platforms
in fairly thick layers, being frequently turned
during the process.. I have been unable to
find out any particulars as to the results
obtained by such a method.

When in Fernando Po in 1899, I saw on
three of the plantations a primitive method
of drying by means of tunnels,’ ro m. (32 ft.
gin.) long by 2 m. (6 ft. 6 in.) wide, and
1°75 m. (5 ft. g in.) high. These were heated
by two pipes running along the floor through
which the heated air was conducted from a
furnace at one end of the tunnel. In each
side-wall there are ten doors, each 1 m. (3 ft.
3 in.) wide ; through each of these, eight trays
can be pushed and placed on ledges, one over
the other. The total area of the trays is
150 sq. m. (180 sq. yd.). Since there is but
very little circulation of air in these’ tunnels,
the distribution of heat is very unequal. The

* Some think the latest ‘tunnel’ systems will be
freely adopted in the future—H. H. S.

8

114 The Fermentation of Cacao’
time required for completing the process was
stated to be two days.’

Consul Spengler, now in Lisbon, but
formerly manager of the Monte coffee planta-
tion in San Thomé, introduced a modern type
of tunnel-drying some years ago. Indepen-
dently, and without knowing of this method,
I also worked out a scheme of tunnel-drying,
which differs from that of Spengler in that
a ventilator is attached to one end of the
tunnel, and the construction is as follows: Two
tunnels, divided by a middle wall, are 20 m.
(65 ft. 6 in.) long, 1°5 m, (4 ft. 11 in.) wide,
and 1°75 m. (5 ft. 9 in.) high. A 20-cm. or
8-in. gauge rail runs down the centre of each
tunnel, the latter being closed at the ends by
double doors. In a convenient position at one
_end of the tunnels is a heating apparatus from
which the hot air is driven through the venti-
lators into the separate tunnels. In order to
increase the draught, a flue communicates with
the other end of each tunnel, just as in Spengler’s
method, and this draws off the hot air. Trays
filled with cacao are placed on small trolleys
and these are run into the tunnels, and as soon
as the cacao on the front trolleys are suff-
ciently dried, these are run out at the other
end, where the hot air enters, and the trolleys
on which the cacao is not yet sufficiently dry

' This is on the principle of the American fruit dryers,
and cannot prove a success unless a fan, or other means
for providing a forced draught, is supplied.—H. H. S.

Dr. A. Schulte im Hofe 115

are then pushed towards the hot end and a
corresponding number of trolleys, with a fresh
batch of beans, take their place. Thus the
warm dry air first passes over the already
partially dried beans and then over the moist
ones, ultimately escaping through the flue.
The warm air is thus utilized to its utmost
extent, and at the same time drying can be.
carried on rapidly and at a comparatively low
temperature. The small amount of motive
power required to drive the ventilators can be
supplied on most plantations by small water
turbines.

Whatever system may be selected, the main
thing always is to use the lowest possible
temperature for drying, but, above all, any
further acidification, or the formation of butyric
acid and the development of moulds, must be,
avoided.

The Oxidation of the Cacao.

Nowadays, industries in which the material.
used has to be fermented are all worked on a
scientific basis. Nevertheless, long practical
experience is needed, as, for instance, to pro-
duce a good quality of malt or to brew good
beer. Such trades require special scientific
institutes to which the manufacturers can turn
at any time for advice when unexpected results
or irregularities occur in their work. Un-
fortunately, as regards the treatment of cacao,
such an establishment is, at present, practically

116 The Fermentation of Cacao

non-existent. The methods in use, therefore,
are empirical, and under such circumstances
it is a little doubtful whether one ought to
publish anything about a scientific method for
carrying out the work, and indicate. how the
oxidation process I have described, may be
substituted for the methods of fermenting and
drying the beans at present in general use, as
by doing so one runs the risk of the essential
principles of the process not being sufficiently
understood, and this might prevent the work
from being properly carried out. If, therefore,
in spite of this, I still give some directions,
I only do so in order that some of the planters
may be enabled to carry out -the necessary
experiments. I should, however, like to warn
my readers against being over-hasty in arriving
at conclusions from the results they obtain if
these do not work out exactly as they desired
or expected. What should be done is to intro-
duce the process on one plantation in each
colony, a scientific expert specially trained to
the work being engaged to assist, and only
when these two, the scientist and the planter,
together have thoroughly mastered the pro-
cess, to then introduce it generally to the other
estates. In order that advice might be at hand
when required, an expert as described above
should be permanently appointed to, and reside
in the colony, with a suitably equipped scien-
tific institute placed at his disposal, in which
further investigations and experiments could
be carried out and checked.

Dr. A. Schulte im Hofe 117

On the plantations in Samoa, Ceylon, and
other countries growing a similar variety of
cacao, drying on floors suffices for the produc-
tion of quite a good type of produce. This
particular variety may only be slightly acidified
and requires a shorter time for oxidation than
is necessary elsewhere, say in the Cameroons,
for instance. Above all, the cacao must not be
allowed to remain in heaps for several days,
if it is only partially dried. As soon as the
beans have reached a stage where they only
contain about 15 per cent. of moisture, the still
warm cacao must be piled together in heaps,
or put into boxes. The beans need only be
kept warm for a comparatively short time in
order to reach the desired degree of oxidation.

I have several times handled Samoa cacao,
in which the fine aromatic bitter taste had
been completely lost owing to over acidification
or oxidation. Just as it is exceedingly im-
portant to preserve the fine aroma or flavour
of teas grown at higher altitudes, since possess-
ing this enables them to sell at prices higher
than those realized by the stronger teas grown
in the plains, so in the case of Samoa cacao,
and others of a similar kind, it is important
to fully develop and preserve the -pleasant
aromatic taste they contain, for just as the finer
qualities of tea are mixed with the stronger
sorts in order to obtain a palatable marketable
article, so are these finer quality cacaos used
for blending with other kinds of a stronger

118 The Fermentation of Cacao

flavour in order to produce a palatable and
marketable chocolate. It is, therefore, exceed-
ingly important in treating this type of bean
to exactly determine the most suitable degree
of acidification and oxidation it should under-
go in the curing. Until this has been done
one is less likely to make a mistake by
employing too short a period of fermentation
and oxidation for the bean than by making it
too Jong.*

In the Cameroons and other places growing
similar types of cacao it is hardly possible to
obtain a sufficient degree of oxidation by the
use of drying floors. A better result will be
obtained if, in using the Guardiola method,
the drying is checked when the moisture
in the beans is reduced to 20 per cent.
stopping it when 15 per cent. is reached.”

1 Does Dr. Schulte recognize that Ceylon and Samoa
cacao are obtained from T. cacao var. criolio, and the
stronger flavoured kinds from T. cacao var. fovastero and
that the first can never altogether become like the
second, and only partially so through hybridization?
The cacao now coming to market from these centres
is often of a darker character, showing that the orig-
inal criollo strain is being lost ; such changes, however,
are not due to the way in which the beans are cured.
—H.H.S.

2 It will at first be somewhat difficult for the planter
to estimate the degree of moisture ; but after a little
practice he will find this quite easy. In order to recog-
nize whether the correct degree of moisture has been
reached, it is only necessary to take the cold bean in
one’s hand and press it to see the moisture content.

Dr. A. Schulte im Hofe 119

The still warm beans. must then at once be
transferred to boxes or made up into large
heaps, to prevent the beans from cooling, and
when this is done the cacao should be pro-
tected from cooling down too rapidly. In
order that the heat may be retained as long
as possible, it would, perhaps, be best to post-
pone disturbing the heaps until the second
day, when they may be turned over with
shovels, as doing so lessens the danger of
over oxidation owing to the cooling of the
beans, provided that oxidation has not already
set in to any considerable extent in the drying
drum.

The process of oxidation at moderately high
temperatures may be more prolonged without
running too great a risk, when the drying is
carried out in drying-houses on two trays
placed one over the other, and, as is done when
malting, the partially dried cacao on the upper
tray is allowed to fall through to the lower one
to complete the drying process. As soon as
the cacao is found to contain only 15 per cent.
of moisture, it is spread out so as to form a
layer about 15 to 20 cm. (6 to 8 in.) deep, and
as far as possible the temperature is kept at
10° to as” C. (nos te 113° F.). Deine this
enables one to maintain an even, temperature

Again, as soon as the amount of moisture in the beans
is excessive, they go mouldy during the process of
oxidation: a sufficient indication of their containing
too much moisture.

120 The Fermentation of Cacao

at the same level as long as desired, whereby
adequate oxidation becomes possible. As
soon as the majority of the beans have turned
brown in their interior the drying is complete.

The heated platforms already mentioned
are very well adapted for carrying out the
process of oxidation. Cacao dried in other
ways can also be easily raised to the required
temperature. If it is inconvenient to leave
the cacao on the platform until it is sufficiently
oxidized, it can be placed in suitable boxes,
and, should it then cool down too rapidly, be
returned to the platform to be warmed up
again, as this also brings about a sufficient
degree of oxidation.

The above directions should prove sufficient
to render it possible for the planter to use such
apparatus as may be at his disposal for experi-
mental purposes, but they will not suffice
when the entire crop is to be submitted to
the process of oxidation. In that case it
will be necessary to erect a special oxidation-
house. This is best done as follows :-—

In the centre of a room 2 m. to 23 m. high
placed level with the ground, either a stone
platform that can be heated, such as | have
already described, or a perforated metal floor
over hot pipes is erected. On this platform
or metal’ floor the partially dried beans are
poured to a height of about 25 cm. (ro in.)
and their temperature raised to the required

1 T would vote against a metal floor.—H. H. S.

Dr. A, Schulte im Hofe. 121

height. Along the walls on both sides of the
platform run boxes, whose outer walls are
fixed, the inner and dividing walls consisting
of loose boards fitting into grooves, so that they
can be adjusted to any height required. As
soon as the cacao has reached a temperature
of 45° C. (113° F.) it is poured into the boxes
and covered over. The next day it is trans-
ferred to the next box, and this process is
continued until the desired degree of oxidation
has been attained. Should the temperature
of the beans sink to about 30° C. (86° F.)
before the process of oxidation is completed,
the cacao is warmed up again. But since the
temperature of this oxidation-house is fairly
high, there is but little risk of the beans
becoming too cool.

The size of such an oxidation-house will
naturally depend on the quantity of cacao to
be cured; a good guide is to calculate 1 cubic
metre (35°315 cub. ft.) to about 500 kilos of
cacao (1,100 lb.). Hence a platform 2 m. (6 ft.
6 in.) wide by 5 m. (16 ft. 3 in.) long, able to
take a layer of cacao 20 to 25 cm. (8 to 10
in.) in depth, will serve to warm 1,000 to
1,250 kilos (19 to 24% cwt.), for which oxida-
tion boxes of about 2 to 22% cubic metres
(about 70 to 87°5 cub. ft.) capacity will be
needed.

Should a tunnel-drying plant be available,
it would be a convenience to build the oxida-
tion-house in such a way that the trolleys can

122 The Fermentation of Cacao

be run straight into it from the drying tunnel.
For this purpose the oxidation-house should
be so arranged that the rails run along the
narrower space on one side of the platform,
whilst the oxidation boxes are arranged along
the other and wider one.

When oxidation has been completed the
cacao must be completely dried; since, how-
ever, there is- but little moisture left to be
removed, the process can be rapidly carried
out, and this can be done, if necessary, in the
oxidation-house.

Tasting the Cacao.

As has already been stated, every tea-planter
is in the habit of daily tasting the tea, after it
has been prepared ready for shipment, in order
to make certain of its quality and also to
ascertain whether its preparation has been
properly carried out. Experience is, of course,
required, but for cacao it need not be as great
as that of the tea taster, who has to estimate
the approximate: market value of the tea. It
will suffice if the cacao planter can determine
how the quality of his cacao compares with that
previously shipped, as well as with those of
neighbouring plantations; this being so he
should test his produce in a similar manner to
the tea-planter. In the case of tea the matter
is somewhat more complicated owing to its
being separated into different qualities by sift-
ing, whereas in the case of cacao only one

Dr. A. Schulte im Hofe 123

sample requires to be tested. In the case of
tea, however, a tasting sample is easily pre-
pared; 120 c.c. of freshly boiling water being
poured on to 3 grm. of tea, and allowed to
stand for four minutes, after which the infusion
is poured off the leaves; whilst compared to
this the preparation of a sample of beans for
tasting is more troublesome. On p. 98 I
mentioned how I introduced the tasting test
for cacao in San Thomé. The apparatus used
was cheap, but the beans had to be pounded
(zervezben) up in a mortar and this was a very
troublesome process.’ I should strongly advise
the use of a small rolling machine, such as is
used for this purpose in chocolate factories.
In preparing the cacao for tasting, 50 grm. of
beans are roasted in a small drum, such as is
generally used for small quantities of cacao.
It will be found that the roasting can be most
conveniently done on plantations over a small
petroleum stove. It is very difficult to make
a definite statement as to how long and at
what temperature the cacao should be roasted ;
this must be learnt by experience. As a rough

1 And yet on many of the estates in Trinidad we
often had to pound up each morning, before breakfast,
the beans to be used as chocolate during the day. This
was done in the well-known wooden mortar which
stands on the ground, whilst the tall pestle or rammer
is worked by the operator, standing, in the same way
as the men in London and elsewhere use a stamper
to lay flag-stones, wooden pavements, or cobbles.—
H.H. S.

124 The Fermentation of Cacao

guide, I may say that the roasting should be
stopped when the shells tend to spit or crackle
(platzen), which may be recognized by a
crackling sound. After roasting, the shells
must be removed, and after cooling the beans
are broken up in a coffee-mill to about the size
of buck-shot; these are then rubbed into a
fine powder by being passed through a machine
with rollers. Six grammes of this fine powder
are mixed with 100 c.c. of water and then
brought to the boil.t The colour of the in-
fusion, the taste, and aroma are the points
by which the quality is judged.

The Export of the Beans.

It would be an ideal state of affairs if a
‘plantation could produce cacao in bulk of
uniformly good appearance and flavour all the
year round. But this is as unlikely to occur
in the case of cacao as it is with any other
plantation product. The great value attached
by the trade to the proper packing of their
purchases and to the goods being graded
according to quality, &c., is seen to a very
marked degree in the case of indigo. From
each plantation in Bengal samples of each day’s
product, marked with consecutive numbers, are
sent after the crop to the broker in Calcutta,
and the: entire output is packed according
to his instructions.

Tea is also packed according to quality,

1 Half water and half milk may also be used.

Dr. A. Schulte im Hofe 125

which is marked on the outside of each case.
A sample of each quality is sent to the broker
and a similar sample retained by the planter.

Now, although on a well-managed cacao
plantation, provided with modern machinery,
there can never be such great differences in
the quality of the produce as occur in the case
of indigo and tea, far more attention should
still be paid to this point when shipping the
cacao than is done at present. To-day the
demand is for large parcels of uniform quality,
so that all shipments should be as large as
possible. It is not, therefore, advisable to put
each day’s produce up into separate bags for
shipment, but to bulk the total output. The
cacao can be kept in separate heaps, if nearly
of the same quality, until the next shipment
has to be made, but when this takes place, it
must then be carefully bulked before being
bagged, so that the quality will be even
throughout.

Samples should be forwarded of each separate
shipment, and, if there are different qualities
in that shipment, then send samples of each
quality to the head offices, consecutive num-
bers being used; duplicate samples are then
kept at the plantation, so that should some
particular lot find special appreciation in the
market, or should some complaint be made
about any lot, it will be easy for the. head
office to refer the matter back to the estate.
The planter could then taste his duplicate

126 The Fermentation of Cacao

sample, and he would thus gradually gain a
knowledge as to what kind of goods are in
demand. The duplicate samples should be
carefully preserved from the damp by being
packed in metal boxes or in suitable glass
receptacles,

I need hardly mention that the packages
z.¢., the bags, shipped sboule be uniform in
shape and weight.

The Fermentation of Coffee.

When, in 1902, I had brought my investiga-
tion relative to cacao fermentation and oxida-
tion to a successful issue, it was natural that
the idea should strike me to extend my experi-
ments to coffee. In this matter, however, I
could obtain no definite results in Germany,
so I renewed my experiments in San Thomé,
using freshly gathered coffee. I found that,
contrary to what occurs in cacao, acidification
had an unfavourable influence on the quality
of coffee, for it slowly caused the beautiful
greenish-grey colour to again become the
yellowish-white of the freshly gathered beans,
in which case an infusion of the roasted beans
tasted flat and had no body.

In my first experiments I treated the freshly
gathered beans, after freeing them as much as
possible from the fruit pulp, just as I did with
the cacao beans; that is to say, I subjected
the coffee-beans to an alcoholic and acetic fer-
mentation, and allowed the oxygen of the air

Dr. A. Schulte im Hofe rag

to act on the washed and partially dried beans
at a temperature of between 40° and 45° C.
(104° to 113° F.). The result of these experi-
ments was as previously mentioned. It some-
times happened that some of the beans only
showed white spots, which grew larger if the
beans were left standing. In isolated cases [
came across such spots on fully cured coffee
that had been stored for some time on the
plantation: The yellowish-white colour of the
coffee, as well as the, white spots on the
isolated beans, were caused by acidification.

If non-acidified, partially dried beans were
kept for some time at a temperature of 40°
to 45° C. (104° to 113° F. ), a sufficient amount
of air being allowed to reach them, the
yellowish-white colour of the freshly gathered
beans turned into a greenish-grey fairly rapidly,
and this colour remained. In treating coffee,
therefore, care should be taken that no acid
can penetrate into the kernels or cotyledons of
the beans, which is enclosed in a parchment-
like skin.

On plantations fitted with modern machinery
the method of procedure is as follows: By a
mechanical contrivance the parchment covering
the coffee beans is separated from the fruit,
and the beans are then fermented and washed.
This fermentation facilitates the removal of
the remaining slimy fruit pulp, and thereby
renders the parchment-like skin more permeable
to air. Should acid fermentation take place,

128 The Fermentation of Cacao

the coffee may very likely be damaged and
so be less valuable. Although it is true that
the acid cannot apparently penetrate the
parchment-like covering of the coffee beans
as easily as it does the shell of the cacao bean,
since fermenting the coffee greatiy facilitates
its being washed, it is practically impossible to
avoid having to prepare the coffee in that way.’

In San Thomé a method that completely
differs from the above is employed as a rule.
The coffee fruit is spread out on cement floors
in the open air in fairly thick layers. There
it is left for weeks, only being occasionally
turned over with shovels. The beans gradually
die, and only after they have done so does the
actual drying commence. The beans are not
left spread out, but are gathered up into heaps
or rows in the evening, and spread out again
the next morning, and during this process a

' According to Dr. Ure, coffee contains: vegetable
fibrine, fatty matter, caffeine, legumine, and it is
claimed that owing to the pressure and friction which
take place in some of the mechanical peelers and
polishers, the coffee gets excessively heated, and the
oil or fatty contents are brought to the surface of the
“beans, and gradually evaporate when the coffee comes
out of the peeler and is exposed to the atmosphere,
losing thereby its natural colour very quickly. Accord-
ing to Messrs. McKinnon and Co., Ltd., of Aberdeen,
this excessive heating can be avoided, as by the simple
though effective method, introduced in their machines,
of circulating cold air between the internal parts of the
machine, a brilliant and lasting polish and colour is
imparted to the beans.—H. H. S.

Dr. A. Schulte im Hofe 129

rise of temperature takes place. After being
dried the bean is separated from its parchment-
like covering and any of the dried pulp (/vezsch)
that may still be adhering to it. This process is
at least the one I saw used on Boa Entrada
plantation, where the coffee was of very good
quality. On beans that had been stored for
a longer period I found the spots already
referred to on isolated beans, and I attribute
their presence to damage done to the
parchment-like covering during the drying
process.

By this method, as practised in San Thome,
the object of the treatment, though carried
out empirically, is to warm the partially dried
beans during the process of oxidation. As
results prove, a very good quality coffee may
be produced by these means. It is certainly
true that by the more modern method—the
removal of the pulp immediately after gather-
ing—a good result can be obtained more
rapidly and with greater certainty, so long as
acidification of the beans is avoided and the
oxygen of the air is allowed to act on them
for a sufficient length of time. As soon as
the acidification is too great—z.e., if the acid
is allowed to penetrate the parchment-like
skin and attack the bean itself—the coffee
will taste flat to the palate and the liquor has
no body, and if the oxidation process is not
carried sufficiently far, a harsh, bitter-tasting
coffee is obtained.

b,

130 The Fermentation of Cacao

The Fermentation of Tobacco.

In connection with my investigations regard-
ing cacao and coffee fermentation, I made
some experiments on tobacco fermentation
in Germany. Unfortunately I have not had
any opportunity of becoming acquainted with
tobacco fermentation carried out on a large
scale. To judge by the results I have obtained
in my investigations into the fermentation of
indigo, tea, cacao, and coffee, I think myself
justified i in assuming that in the case of tobacco
too much importance is also attributed to fer-
ments. I was indeed of the opinion that in the
case of the fermentation of tobacco, as with
the other products, the oxygen in the air plays
the most important 7é/e, and that the packing
together of the nearly dried leaves in heaps
has for its aim the production of a temperature
suitable for the process of oxidation. I fur-
ther gathered that the packing and repack-
ing (#mpacken) of the heaps was not only
done in order to. avoid both the production
of too high a temperature as well as the
formation of butyric acid and moulds, but also
in order to bring the leaves into contact with
the oxygen of the air. The heating of the
tobacco heaps is, of course, brought about by
the influence of micro-organisms, and it is the
sole object of the process just described to
bring this about, z.¢., to raise the temperature.
If the leaves contain too much moisture,
too great acidification sets in, and if there

Dr. A. Schulte im Hofe 131

be an insufficient supply of air, butyric acid
fermentation, &c., will take place. In order
to avoid these, the leaves have to be par-
tially dried, but still kept moist enough for
oxidation to become possible. The production
of good tobacco depends on proper attention
being paid to these conditions for a sufficient
length of time, and on stopping the fermenta-
tion as soon as a sufficient degree of oxidation
has been reached. Since the desired tempera-
ture is caused by micro-organisms, naturally
their conditions for growth must be taken into
consideration. If the necessary temperature
can be supplied artificially, the micro-organisms
can be dispensed with.

Seeing this, I therefore tried the following
experiments: Some tobacco leaves, having
varying degrees of moisture, were. exposed in
a large glass receptacle to a temperature of
between 45° to 55° C. (113° to 131° F.). In
order to ensure that they had access to suffi-
cient oxygen, the leaves were exposed to
the air daily, whilst with the control-tests,
this airing was omitted. Having determined
by repeated experiments the proper degree of
moisture, I allowed the process of oxidation
to continue for varying periods. By this
means I was able, after treating the leaf for
fourteen days at temperatures between 45° to
55° C. (113° to 131° F.), to obtain a tobacco
that was declared to be of good quality, and
which kept perfectly well. Leaves subjected

142 The Fermentation of Cacao

to the oxidation process for shorter periods
were declared to be unripe, and sharp in
flavour.

The freshly-gathered and dried tobacco-
leaves used in my experiments were kindly
supplied to me by Herr J. Hammerschlag,
manager of the Kaiserliche Tabak-Manu-
faktur, Strassburg, who also submitted the
tobacco leaves fermented by me to expert
tests, the results of which I have given
above.

I have therefore proved that with tobacco
also, fermentation plays only a_ subsidiary
part, the object of which can be attained by
artificial heat, but that the main results in the
curing are attributable to the oxygen in the air.
The essential principle of tobacco fermentation
is then to allow the oxygen of the air to act
on the leaves under conditions favourable to
oxidation—that is to say, at moderately high
temperatures.

I have mentioned my researches on coffee
and tobacco fermentation, in order to show
that in their case the oxygen from the air
also plays the same 7é/e that it does with
indigo, tea, and cacao fermentation, or, rather,
oxidation. In actual practice it is true that in
the case of indigo the oxidation takes place
in a watery solution, but if the leaves of the
indigo plant are strongly compressed—in other
words, if they are treated as one does when
rolling tea-leaves—oxidation will also occur

Dr. A. Schulte im Hofe ta2

with indigo leaves as well, in fact it takes
place very, rapidly; and in some countries
indigo is prepared in a primitive manner,
similar to above. As the oxygen takes longer
to obtain access to the interior of the cacao
and coffee bean, the process of oxidation
lasts much longer. The same seems to be
the case with tobacco leaves. .If one could
treat these as one does tea-leaves, z.e., if the
oxygen could obtain easier access to the
interior of the tobacco leaves by some
mechanical process corresponding to the
rolling of tea-leaves, its ability to do so
would certainly be able to greatly accelerate
oxidation. I succeeded in shortening the time
considerably by simply maintaining the con-
ditions favourable to oxidation.

These notes, like the investigations, are,
of course, in no wise complete. It is, as a
rule, far more difficult to adopt scientific
results in actual practice than to explain
empirical methods scientifically.

CHAPTER V.
By Dr. J. SACK.

WHEN one considers how the cacao crops
in Surinam were handled in the past, as
_compared with the present, one comes to the
conclusion, that since the commencement of
the cacao plantation industry in this colony
-—it was in the year 1773 that the first ship-
ment of cacao to Holland took place—the
mode of fermentation has scarcely changed
at all.

Formerly the seeds were placed in one big
heap in the shed, and covered with banana
leaves, and this method of fermentation is still
resorted to occasionally, The cacao was left
to sweat for five or six days, the heap being
turned over each morning. After this the
damp seeds were thinly spread over the floor
of the drying attic of the shed, and finely
sifted ash or powdered clay was scattered over
them.

Here the seeds remained until they became
dry, which was a matter of five weeks at least.
During that time the seeds were repeatedly
turned over, and if any maggots were found on
the cacao, it was sprinkled over with salt or
brine.

Dr. J. Sack 135

It is remarkable that at that time the sun’s
rays were considered to be highly injurious
to the cacao, hence the beans were dried in
lofts or attics, which, while being as airy as
possible, were yet secluded from the sun.'

——9

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Dr. J. SACK.

As regards the process of drying, the methods
followed at the present day, when rapid drying
is aimed at—either by mechanical means or in

1 The cacao used preferably to be shipped in vessels
which also carried sugar, as it was believed that both
the aroma and the taste were enhanced by the presence
of sugar.

136 The Fermentation of Cacao

the sun —are very different to those utilised
in the past.

This rapid drying is not resorted to because
it is considered that better cacao is obtained
by its use, but because the old method would
take up too much room in the sheds, now that
the cacao plantations have increased so much
in size, In the old days indeed, cacao was a
secondary product of the coffee plantation, in
fact even at the very commencement of the
industry, the cacao was sometimes dried in
the sun when the coffee crops were abundant.

The mode of fermentation, however, has
practically remained the same, except that now
the beans are usually placed in a special
fermentation or sweating-house; that is to
say, a stone building, roofed with tiles, and
divided into five to eight compartments or
boxes made entirely of wood.

In each of these sweating-boxes the cacao
remains lying in a heap for the space of one
day, to be turned into the next the following
-morning, when at the same time care is taken
that the beans which were at first on the top
now go to the bottom.

The floor of the boxes, which is also of
wood, is bored with a number of holes; it is
built over a cement floor which slopes slightly
forwards. This enables the water or juice,
which exudes from the fruit pulp by reason
of the pressure of the heap, to flow into gutters
alongside of the boxes, and thence outside.

Dr. J. Sack 137

The fermentation takes from five to eight
days in all, according to circumstances, and
the planter can see by the look of the beans
whether they are sufficiently fermented or not.
The process is thus exactly the same, practic-
ally, as it was about a hundred years ago.

Very little is actually known of the changes
that take place in the beans except that the
temperature rises during the fermentation, and
that it is necessary to turn over the heap, or
to shift it from one compartment to another
in the sweating-house so as to prevent the
rise of temperature from becoming excessive ;
further, that during the fermentation the
slimy pulp which envelops the seed becomes
loosened and fluid so that it is able to run
off as a liquid ; and that the seeds themselves
change colour, z.¢., from pale violet to brown,
while they are changed from a fleshy leathery
substance to a brittle one, and the pellicle of
the seed, after the fermentation, becomes a loose
and brittle skin surrounding the cotyledons.
One can well say, therefore, that although this
process has been applied for many years when
preparing the beans, very little is known so
far concerning the changes which the fer-
mentation brings about in the cacao.

But besides these changes there must be
others more important, which, however, are
less easily perceptible ; and these, still un-
known, changes must be those without which
the unfermented product is unsuitable for the
manufacture of cacao.

138 The Fermentation of Cacao

One may thus safely say that, for the present,
itis difficult to assert with what object the cacao
is fermented, and as long as this is the case,
there can be no question of arriving, along
scientific lines, at an improvement in the
sweating process, whereby a product of higher
commercial value would be obtained.

The following are the results of a few experi-
ments made with a view of explaining certain
problems arising in connection with the fermen-
tation of cacao beans.

In answer to the first query, viz.: Zs the
fermentation of the cacao due toa chemical or
brological process ?

It is conceivable that the fermentation is the
result of chemical reactions, which take place
in the substances contained in the pulp or the
seed, without bacteria, fungi, mould: or other
forms of life playing a part therein. If this is
the case, then the fermentation process is due
to chemical action.

It is, however, also conceivable that forms
of life as mentioned above,. attack the pulp,
multiplying greatly, and that they constitute
the primary cause of the first fermentation pro-
cess. If this is the case, the fermentation must
be due to a biological process.

The latter supposition at once appeals to us
as being the most likely, since the soft pulp,
which contains a considerable amount of water
and sugar, is recognized as an excellent form
of nourishment for moulds and fungi; a test,

Dr. J. Sack 139

however, was first necessary in order to decide
this positively.

For this purpose four baskets were taken,
each filled with 7 kilos of cacao. These
baskets were placed upon stones to allow the
liquor to drain away.

To the baskets Nos. 1 and 2 nothing further
was added; to the contents of basket No. 3 was
added a certain quantity of formaldehyde, and
to the contents of basket No. 4 some chloroform.
Now formaldehyde and chloroform are both
substances which exercise a stupefying or even
deadly effect upon all forms of life, but do not
disturb chemical combinations; therefore, if
the fermentation is due to a chemical process,
the temperature in the four baskets would have
risen to the same level; and if to a biological
process then in that case the temperature in
baskets Nos. 1 and 2 would have risen, and that
in baskets Nos. 3 and 4 would have remained
at the level of the surrounding atmosphere.

In process of time the temperature in baskets
Nos. 1 and 2 rose to 40° C., while that in baskets
Nos. 3 and 4 remained at the level of the sur-
rounding atmosphere, that is to say 28°C. In
baskets Nos. 1 and 2, where the fermentation
was thus in full operation, some chloroform was
placed, as a further proof, whereupon the
temperature after some hours dropped from
40° C. to 28° C., and fermentation ceased.

From this test it thus follows that the fer-
mentation of the cacao beans is not due to a
chemical but to a btological process.

140 The Fermentation of Cacao

In answer to query No. 2: Does ¢he fer-
mentation require the admittance of air ?

Four cylinders were filled, each with 4 kilos
of cacao. Each of the cylinders had a tube
attached to allow of the drainage to run away.

Cylinders Nos. 1 and 2 were open at the top,
and drilled bamboo canes pushed in between

the cacao, so that a sufficient quantity of air
could penetrate. Cylinders Nos. 3 and 4 were
tightly closed.

After a time the contents of cylinders Nos. 1
and 2 duly began to ferment, while the cacao
in cylinders Nos. 3 and 4 began to decompose ;
this experiment. was repeated several times,
but each time the air was excluded the fer-
“mentation ceased and the cacao commenced to
decompose.

’ This test therefore proves that the fermen-
tation process reguires the admittance of atr.

In the laboratory the best fermented cacao
was obtained from the baskets, as they were
open all round, and the air could thus penetrate
freely, and in ‘studying the process of fermen-
tation on the plantations, it appears that with
large heaps the top layer ferments the best,
and that the bottom of the heap, where the air
cannot penetrate, does not ferment at all.

It is thus proved that turning over the heaps,
that is to say, transferring them from the one
sweating-box to another, whereby the layer
that is at the top goes to the bottom, is not
without good reason; in fact it is necessary in

Dr. J. Sack . , qt

order to ensure that the beans are evenly
sweated throughout, and to arrest decompo-
sition.

Query 3.—J/s the rise of temperature due
to the conversion of the sugar contained in the
pulp ?

The supposition that the rise of the
temperature is caused by the conversion of
the sugar in the pulp, arose from the observa-
tion that, after the fermentation, the pulp
contained no more sugar, while the air was
pervaded by a strong smell of acetic acid ;
an element readily produced from sugar.

Supposing this theory is correct, there
should be no rise of temperature if the
seeds are placed in the sweating-box after
the sugar has been removed from the fruit
pulp.

In order to prove this, two baskets were
. filled with cacao in the same way; No. 1
contained cacao to which nothing had been
done; No. 2 contained cacao which had
previously been washed. The contents of
basket No. 1 proceeded to ferment in the
usual way, while the contents of basket No. 2
did not ferment at all, until after it had been
sprinkled over with a solution of sugar.
Simultaneously with the disappearance of the
sugar, however, the presence of alcohol and
acetic acid was observed. From this test, and
also that on page 139, it is thus seen that the
rise in the temperature of the cacao in the

142 The Fermentation of Cacao

sweating-boxes is caused by a fermentation
process, whereby the sugar present in the
fruit pulp changes into alcohol and this again
oxydizes into acetic acid. Both the alcohol
and the acetic acid were chemically shown.

Experience shows indeed that when much
rain falls' during the gathering of the cacao,
the sugar is washed out of the cacao and it does
not sweat properly ; but we soon also learn
that this drawback may be remedied by adding
a certain quantity of molasses after the cacao
has been taken to the sweating-house.

During the laboratory experiments the
temperature in the baskets could not be raised
above 40° to 42°C., while that in the sweating
heaps on the plantations usually represents 42°
to 45° C.; this is easy to understand, as with
the baskets, the surface is too large in pro-
portion to the quantity of cacao and there
is thus much loss of heat.

The foregoing relates entirely to the pro-
cesses which take place in the pulp during
fermentation, and which we may collectively
call the external fermentation; on the other
hand, we have the internal fermentation, that
is to say the processes enacted in the bean
itself.

1 It should here be remarked that the seeds on most
plantations are sent into the sweating-house already
stripped of their husks, which is done on the estate, and
the contents are then taken in baskets to the fermenta-
tion house.

Dr. J. Sack 143

The phases of the external fermentation, as
observed with the tests described, may be
contained in the following :—

Immediately the seeds are placed in the
sweating-boxes, the fungi and bacteria sur-
rounding them, and which are to be found
upon the cacao, change the sugar out of the
pulp into alcohol, thence into acetic acid,
subject to the necessary development of heat.

To what form of life they belong may be
gauged with a tolerable degree of certainty,
as the changing of sugar into alcohol, thence
into acetic acid, is a well-known process.

The decomposition of sugar into alcohol
is probably due to a fermentation fungus ;
from sugar and water there arise alcohol and
carbonic acid gas.

The decomposition of alcohol into acetic
acid is probably caused by a certain kind of
bacteria. It is an oxidation process, that is
to say the alcohol unites in this way with
oxygen, and that according to the following
formula :—

C,H,O + O, = C,H,O, + H,0.
Alcohol Oxygen Acetic acid Water

Consequently oxygen is required for this
decomposition, which is the reason why, as
we could see from the test on page 140,
the fermentation needs the action of the air.
With the decomposition of the alcohol into
acetic acid heat develops.

144 The Fermentation of Cacao

And now to proceed to the internal
fermentation, or the processes enacted in the
bean itself.

As long as the bean lives but remains ina
dormant state, no chemical changes of any
consequence take place, as the various sub-
stances contained init do not come into contact
with each other. The seed, however, is no
sooner dead than the substances of which it is
composed begin to react upon each other.

The seed remains alive until the high tem-
perature brought about by fermentation kills it ;
and in order to determine at what temperature
this takes place, the following tests were
made :—

The seeds of four ripe cacao pods were
thoroughly mixed and twenty of them planted ;
as they all germinated they may be taken to
represent good germinative seed.

Ten units were submitted to a temperature
of 43° C. for three hours, whereupon they were
left to germinate, which they all did.

Ten units were submitted to a temperature
of 43° C. for six hours, and then left to germi-
nate ; of these only four germinated, and after
having been heated for nine hours not one of
the seeds germinated.

Ten units were heated to 44° C. for six
hours ; the germs of these seeds all proved to
be dead.

In the sweating-boxes thé temperature on
the third day is usually 45° C., and hence from

Dr. J. Sack 145

the above test it may be concluded that by the
fourth day all the seeds would have been dead,
and so from this moment one may conclude the
internal fermentation commences.

Change of Colour of the Seed.

Seeing that with the fermentation of the
pulp no substances arise which could be
expected to exercise any influence worth speak-
ing of, it seems probable that the changes
which take place in the seed during fermenta-
tion depend upon the mutual action of the
substances which are actually présent in the
seed itself. With the change of colour (from
violet with the unfermented to brown with the
fermented seeds) this indeed was proved to be
the case.

When crushing cacao seed in a mortar
-one can already see, during the process,
the violet colour changing into brown, which
gets darker and darker the longer the cacao is
left standing, and from experiments it was
further proved that the brown colour only
results with admission of the air; as a matter
of fact, this is also the case with the fermentation
of the beans, the brown colouring working from
the outside to the inside; at the same time it
appeared that this discolouration did not take
place after the beans had been placed for some
time in boiling water, but when, however, a
few fresh beans were rubbed through this boiled
mass the brown colouring showed itself after a

IO

146 The Fermentation of Cacao

time. This phenomenon led one to suppose
that the action was due to the working of
enzymes.

It is difficult to give a concise, and at the
same time a good definition of what is under-
stood by an enzyme, but, speaking generally,
one may say that enzymes are substances of
vegetable or animal origin, which have’ the
power of causing reactions between certain
substances, without themselves playing any
part in the composition of the substances
formed by the said reaction; they are thus
able, in minute quantities, to manipulate the
decomposition of great quantities of these same
substances; the enzymes are made harmless at
a temperature of 100° C., most of them at a
lower temperature still, viz., between 65°C.
and 70° C., while the temperature at which the
enzymes exhibit the greatest activity (the so-
called optimum temperature) lies, for the most
part, between 45°C. and 60°C. As regards
the chemical composition of the enzyme nothing
‘is known so far.

In order to be positively: certain that the
discolouration is actually due to the presence of
an enzyme, attempts were made to isolate same.
This was done as follows: The cacao beans
were thoroughly washed with water, so as to
remove the sugars, acids, &c., whereupon -they
were crushed to pieces, and steeped into alcohol
so as to be able to remove the seed pellicle
easily. The seed pellicle contains much slime,

Dr. J. Sack 147

which would obstruct the removal of the enzyme
by water very considerably, so for this reason
it was removed. The alcohol was rapidly
poured off, and the kernels exposed to the air
until the alcoholic smell had disappeared ; this
took place within a few hours ; the beans were
then reduced to a pulp and ether poured over
them, and then run off to remove the greater
part of the fat.

Having again been dried in the air, the
cacao was mixed with water, and, after being
shaken, left to stand for six hours; it was then
filtered through sieves and afterwards through
linen. Whilst being filtered alcohol was added,
and the fine flaky precipitate, which sinks
rapidly, freed by pouring off the fluid on top.
The residue was washed with alcohol and
ether, and dried in the air, and a light brown
mass containing much nitrogen was obtained.

About half a gramme of this residue was
obtained from several kilos of seed. The
material was not further refined, as the work-
ing of ferments is strongly retarded with this
operation of repeated solution and _precipi-
tation.

Now, as already mentioned, the finely
crushed beans do not discolour after having
been placed in boiling water, but they do if
a few fresh beans are mixed with them. In
lieu, however, of intermixing some fresh beans,
the enzyme containing residue was added, and
after a few hours the discolouration set in.

148 The Fermentation of Cacao

As a further check the residue, at another
test, was heated for five minutes to 100° C.
before adding. the violet mass; here after
standing for days there was not the slightest
trace of change of colour.

From these tests it follows that the dis-
colouration of the beans, which die at a tem-
perature of about 45° C. during the fermentation,
is caused by a substance contained in the seed
itself, and which must be an enzyme, seeing
that it can be destroyed by boiling heat, is
precipitated by alcohol, and causes the dis-
coloration by the medium of a minute quantity.
The temperature at which the enzyme is
destroyed appears to be somewhere about
FO Ta.

For the purpose of ascertaining the activity
of the enzyme-containing residue, a few further
tests were made, In these it was noticed that
cane-sugar did not split, an invertase thus
appeared to be lacking. Amygdalin, however,
did so.

This observation gave us an idea as to the
nature of the reaction which causes the beans
to turn brown.

In the beans, the above-mentioned glucoside’
does not exist, but another, z.e., cacaonine, is

1 By glucosides are understood those substances
which by the action of acids, alkalis or enzymes become
divided, so that in addition to more or less compound
bodies a kind of sugar, usually dextrose, forms. Glu-
cosides appear almost exclusively as plant substances.

Dr. J. Sack 149

present, as has been demonstrated by Hilger ;*
this cacaonine has as formula: CyH,O,N,,
and shows upon analysis one molecule cacao-
red, six molecules grape sugar and one mole-
cule theobromine.

We have already said that the admission of
air is necessary to bring about the discoloura-
tion. This becomes clear when one considers
that, as shown in the above analysis of
cacaonine, oxygen is necessary,

One molecule theobromine has the following
composition :— °

C;H,O,N, six molecules glucose, 6 C,H,.0,
=C,;H,.O,,; one molecule cacao-red: C,,H Oy.

In all these contain, 60 atoms C, 102 atoms
H, 48 atoms O, and 4 atoms N; this sum
thus contains 16 atoms H, and 33 atoms O,
more than a molecule cacaonine.

These 16 atoms H, and 33 atoms O, are
produced by § molecules water and 25 atoms O.

The formula of the enzymitic division of the
glucoside cacaonine thus becomes :—

CoH 0,N, + 8 H,0 + 25 O=

Cacaonine Water Oxygen
C,H,O,N, + 6 C,5Hy,0, + Cy Hero
Theobromine Dextrose Cacao-red

The chief thing in this reaction is the
origin of the theobromine, the alcaloide, which

1 I had no literature at my disposal upon the subject
of cacaonine and cacao-red, except that contained in
Zipperer. Die Schokoladen fabrikation 2 Auflage, Berlin,

IQIO, Pp. 50.

150 The Fermentation of Cacao

imparts to the cacao its irritating and bitter
characteristics.

So far the cacao-red has been considered to
be the substance which gives the manufactured
cacao its characteristic aroma and taste, and in
order to ascertain whether this was correct, the
cacao-red was prepared in the manner indicated
by Hilger and Lazarus. On doing so, how-
ever, it proved to be a perfectly odourless and
tasteless powder, so that one cannot ascribe the
aroma and taste of the manufactured cacao to
this substance. .

What did appear was that the aroma of the
cacao was considerably increased by the process
of fermentation. Fresh unfermented beans,
when subjected to boiling, do not smell. It
must, therefore, be concluded that the aroma
is caused by a substance which, like the cacao-
red, first originates with the fermentation process.

The fact that fermented cacao, when sub-
jected to boiling, smells strongly, led to the
supposition that the substance in question was
an ethereal oil, since ethereal oils have the
peculiarity of evaporating with steam.

In order to trace this, a large quantity of
ground cacao that had been fermented was
distilled by steam. The distillation was again
distilled to a smaller volume, and this opera-
tion was repeated several times. In_ this
manner a drop of oil was obtained, which
strongly resembled cacao in its peculiar smell
and taste.

Dr. J. Sack 151

During the distillation the laboratory and
the entire surroundings were pervaded by a
strong smell of cacao. The yield was extremely
small, and it may be estimated that 20 kilos
of cacao will produce 1 c.c. of cacao oil. This
experiment at the same time made it quite
clear why the old method, by which the drying
was done slowly, yielded a product which far
surpassed in quality the cacao that was rapidly
dried, for with a slow process of drying the
reactions will continue for some considerable
time. With rapid drying they will speedily cease.

The above may be summed up as follows :—

With sweating the beans, an alcoholic fer-
mentation in the pulp first takes place through
the agency of ferment fungi, whereby the sugar
contained in the pulp is split into alcohol and
carbonic acid; the alcohol with the addition
of oxygen is further oxydized into acetic acid,
which causes a strong rise of temperature.
This is the external fermentation. This causes
the temperature to rise to about 45° C., when
the seeds or beans enclosed in the pulp are
killed. After this has taken place, the sub-
stances within the bean itself commence work-
ing upon each other. This is the internal
fermentation. Subject to the influence of an
enzyme present, the cacaonine is split into
cacao-red, theobromine and dextrose, while at
the same time an etherial oil is formed.

Moreover with the fermentation the useless
sugar-containing pulp, which is so detrimental
to the keeping of the cacao, disappears.

152 The Fermentation of Cacao

Loss by Washing the Cacao.

A few determinations were made in regard
to the greater loss of weight the cacao sustains
after fermentation, if it is washed and then
dried, as compared with the method of drying
it immediately after fermentation.

In Surinam one usually estimates that the
loss through washing is very considerable, it
even being admitted to be as much as 15 to
18 per cent.

I found, however, that this depreciation only
came to 4 to 5 per cent., except in a solitary
case of badly-sweated cacao that was dirty,
when it was found to be 8 per cent.

In practice these figures will be lower still,
as smal] lots such as I washed will be more
perfectly and thoroughly treated than large
quantities. Taking this into consideration, the
figures obtained by me compare favourably
with those given by Preuss? in regard to the
loss by washing, z.e., 4 per cent.

When taking into consideration that buyers
in Surinam only pay 2 cents per kilo more for
washed cacao than they do for unwashed, it is
evident that with a low price of 55 to 60 cents,
a loss of profit ensues, seeing that 2°2 to 2°4
cents already is lost by the washing, and only
2 cents recouped; moreover this does not
include the washers’ wages, and other costs
necessitated by the process.

' Preuss, ‘“‘ Reise nach Central- und Sid Amerika,”
I9OI, p. 176.

153

CHAPTER VI.

Forming with Chapter VII., by Dr. Lucius
Nicholls, the Joint Prize Essay mentioned in
the Preface.

By Mr. GEORGE 8S. HUDSON, ERRARD ESTATE,
Sr. Lucia, B.W.I.

Scope of Suggested Improvements.

APPROACHING this subject from a strictly
utilitarian point of view, it is necessary at the
outset to admit the defined limitations with
which we are beset when striving to introduce
improvements in the quality of the cacao by.
adopting the best methods of fermenting and
curing the beans. The changes that may
be induced in cacao by such methods consti-
tute a beneficial action the measure of which
can be most accurately gauged by exactly:
that difference in price which cacao buyers.
in the terminal markets enforce between un-
fermented, carelessly cured cacao and the highly
fermented, well-cured produce from the same
variety of tree and place of export.

With the Calabacillo and Amelonado types
of cacao frotn Brazil, Africa, West Indies, &c.,

154 The Fermentation of Cacao

&c., that constitute three-fourths of the pro-
duction of the world, the extreme difference in
their value when prepared by the methods
now in general use, as compared with the
improved methods described here and else- -
where, may be estimated to-day (June, 1911),
at about 5s. to 6s. per cwt.

Inthe Forastero, Criollo and Pentagona types
from Trinidad, Ceylon, Central America and
Samoa, &c., &c., the difference would appear
to be even less: this is doubtless due to the
fact that the planter who aims at producing a
high-class cacao would not spoil it by poor
curing ; also, that the fermentation of these
types is more simple.

It is impossible to ignore the fact that taking
the world’s production of cacao, no single in-
stance arises of a low-class cacao being trans-
formed by curing methods into a high-class
article, and conversely, one seldom sees Criollo
or Pentagona types so spoilt by curing as to
seriously reduce their value.

That the value of any quality may be en-
hanced by careful treatment, and lowered by
indifferent methods, is apparent, but it is
equally apparent that the enhancement of

1 This is true, but, at the same time, it is agreed that
with the introduction of the best methods of seed-
selection, cultivation, and curing, an indifferent class
of cacao can be improved out of all comparison with
the original stock, as has been proved with the Grenada
cacao of to-day compared with the beans that came to
market in 1883 and 1884.—H. H. S.

Mr. George S. Hudson 155

values by good curing has hitherto been

limited within the difference of price |
have named if badly “weathered” or ‘sea-

(Elliott & Fry.

Mr. GEORGE S. HubsoN.

damaged” parcels be eliminated from the
outlook, as they naturally would be.

156 The Fermentation of Cacao

It is possible that the inoculation method
of fermentation recommended in this essay
will-extend this limit of difference upward by
a few shillings per cwt., but beyond this, if
higher prices are desired, better varieties’ of
cacao must be evolved by seed-selection, in-
tensive cultivation, and the other means well
known to all plant-breeders.

The curing of cacao is in the hands of two
distinct classes, vzz., planters, who cure their
own produce, and ‘merchants who purchase
cacao more or less cured from the small pro-
prietors and complete the process—generally
in an indifferent manner whereby the value
of their purchases is materially reduced.

Planters’ cacao, generally classed in Prices
Current as ‘Fine Estates,” has the advantage
of being in’the planters’ hands from the first
to the last stages of curing; and throughout
the world, and especially in ‘the West Indies; it
is wonderful how “evenly” a sample of cacao
is turned out by all planters whose trees are
nainly ofan Amelonado type with a sprinkling
of Calabacillo and Forastero. Where the pro-
portion of Forastero is. considerable (as on
many, if not all, Trinidad estates), then a some-
what higher quality is produced. Where Criollo
and Forastero hybrids predominate, as in some
Ceylon marks, then the price is‘usually 20 per
cent, to 30 per cent. higher, and the really high-
class Central American or Ceylon growths, com-
posed of nearly pure Criollo or Pentagona types,

Mr. George S. Hudson 157

mav sometimes sell at double the price of a
well-cured Amelonado sample. In comparing
the “Fine Estates” marks of St. Thomé, Accra,
Cameroons, Bahia, Grenada, Jamaica, St.
Lucia and Dominica, there is between the
best and the worst a difference in quality that
most manufacturers do not value at more than
2s. 6d. per cwt., and more frequently the
difference does not amount to more than Is.
or 1s. 6d. per cwt.' In some instances the
size and quality of the seed may influence this
result, but in most cases it is simply a question
of the care and. intelligence expended on the
processes of fermenting, drying and polishing
the beans previous to shipment.

Taking planters and their cacao as a class,
the good cacao with the bad, and the careful
man with the dadsser-aller man, there seems
to be every probability that the adoption of
improved principles in curing, notably Dr.
Nicholls’ inoculation by means of a ferment,
will result in each and.every planter obtaining

1 This is not entirely correct, but quite near enough
for the present discussion; at the same time it is in-
teresting to note the differences in quotations on June 16
of the following typical growths :—

1913 Igi2

Trinidads—London ... 72/- to 78/- 65/- to 68/-
Grenadas—London ... 67/- to 73/6 56/- to 62/-
Accras—Liverpool ... 58/- to 63/- 52/- to 58/-
Trinidads—-Havre... Fes. 85 to 89 ~=78'to 81
Haytians—Havre ... ,, 68to82 57 to 71

Venezuelan—Havre ... ,, 85 to 180 73 to 200

158 The Fermentation of Cacao

an increased price averaging 2s. per cwt. net.
The question that each planter is apt to ask
himself on this subject is, ‘‘ Is the game worth
the candle?” Well, on a crop of 300 bags
(of 180 Ib. each) it means an extra net profit
of £45 to men who are already turning out
a relatively good sample. Many estates
could improve the price they realize by twice
as much again, z.e., 4S. cwt., but, writing as an
old agricultural instructor, I am more sanguine
of inducing the man, who is already doing
creditably, to reach up to higher results than of
inducing the man who is in the habit of throw-
ing away’ £50 a year by exporting poor cacao
to amend his ways.

Turning to the merchants’ part in cacao
curing, where the reward offered for good work
is so much larger, and the men engaged in it
are supposed to be very keen on an extra
profit, one should hope for good results, were
it not that the merchants’ past record in this
matter is such an unpromising one. It is not

unusual for a single cacao-buying firm in the
West Indies, Brazil or West Africa, to pur-
chase, cure and export many thousand bags of
cacao each year. Owing to the prevalence of
cacao stealing, most cacao-producing countries
have laws prohibiting the purchase’ of freshly
picked cacao, and, although this complicates .
the curing question for the merchant, yet one
must acknowledge the extreme usefulness of
this precaution in bringing offenders to justice ;

Mr. George S. Hudson 159

it compels the thief to keep the cacao he has
stolen in his possession twenty-four to thirty-
six hours, and this frequently proves his
undoing. The usual procedure of a small
proprietor having cacao for sale to a merchant
is to ‘‘sweat” it one night (which entails no
rise in temperature, and is merely equivalent
to a draining process), expose it to one day’s
sun when it is bagged, and next day, perhaps,
slightly sprinkled with water to make it weigh
a little more, it is then sold to the merchant.
In other cases the drying is continued until it
is more or less “dry” in the accepted term
(generally less), and the produce then sold to
the merchant, who exports it in this condition
as cured cacao. It is then, usually, very un-
attractive, of a dirty grey colour, insufficiently
dried, more or less mildewed, and containing
much of the placenta from the pod. Small
wonder that it sells at a low price, one is
only surprised that it does not fetch an even
lower figure. In some cacao-buying stores an
attempt is made to produce fermentation on
the partially dried bought cacao, by throwing
it as purchased into large packing cases, and
leaving it there for a night or two to take
its chance of fermentation. Its chance is in-
finitely small; such fermenting germs as the
cacao carried away from its brief sojourn in
the ‘‘sweating-box” are killed by the sunning,
and as one seldom sees the ‘Cacao Fly”
(described by Dr. Nicholls) in well-scavenged

160 The Fermentation of Cacao

towns and villages, there is hardly a chance of
fermentation taking place.

To cacao-buying merchants, then, Dr.
Nicholls has pointed a way towards first-class
results, by the isolation and preparation for
everyday use of a pure cacao ferment con-
taining those yeast forms which our experi-
ments have proved to be the most vigorous
and beneficial; and further, by providing a
prescription (which any chemist should dis-
pense for a few pence) of a suitable medium -
that will enable this ferment to flourish by
spraying or sprinkling the combined ferment
and medium on‘either freshly picked or partly
cured cacao. It is not unreasonable to hope
that with the co-operation of Government
Agricultural Departments in cultivating and
distributing this ferment from their laboratories,
the preparation of merchant's cacao should
be revolutionized, and that of pianter’s cacao
much improved. On a very moderate estimate
the merchant should, by this process, allied to
better drying methods, increase the value of
each 1,000 bags he exports by £300. On
the supposition that cacao-buying firms handle
half the cacao output of the world, it can easily
be seen that the potentialities of Dr. Nicholls’
formula would run into larger figures of export
values than I care to estimate.

It is a matter of common belief among cacao
men that the manufacturers are not averse to
a large quantity of low-class unfermented cacao

Mr. George S. Hudson 161

coming into the market at a low price. If this
is so, I will say, for their consolation, that
although I may appear enthusiastic as to
results of the discoveries reported in the
essays contained in this book, yet it is a fore:
gone conclusion that no bait or reward for
good work is likely to ensure the entire dis-
appearance from the market of carelessly cured
cacao.

It would prove a grievously mistaken idea
to imagine that just a sprinkling of this magic
essence on a heap of neglected cacao seed
would, without further effort, transform it into a
high-class parcel. I do not apologize for men-
tioning this obvious fact, for how often is that
attitude not taken up in the manuring of cacao?
Just a little of the magic powder sprinkled on
the ground and crops should be doubled !!
Unfortunately, it is not quite so easy as that.
The preparation of a good sample of cacao is
quite simple, but it does demand a certain
amount of care and attention in every detail.

The margin of profit in the cacao-buying
business must be materially reduced by the
expensive and careless methods used, not to
mention the chances of loss by theft and
“weathering.” The usual procedure is to
spread the seeds out on tarpaulins (which are
costly appliances) in the sun each morning,
collecting them again each evening under
cover. ‘It is true the drying is generally com-
pleted on large garret floors at little expense, but

It

162 The Fermentation of Cacao

no planter could afford to deal with large and
very large quantities of cacao in this manner.
The merchant should have several different
sweating boxes to suit the different degrees
of dryness in the cacao purchased, and to -him
may be recommended, even more than to the
lanter, the advantages that vacuum drying
ane in requiring a minimum of fuel, economy
of time (cacao coming from the sweating boxes
in the early morning can be bagged and
shipped by midday), theft and wastage reduced
to a minimum, as all operations are finished
within four walls in a few hours. At a glance
it is obvious that the merchant can consider-
ably reduce the capital employed on ‘cacao
account” by owning a vacuum dryer; also,
he can reduce his risk of the market going
against him by.two or three weeks. In fact,
it would revolutionize the business ; profit and
loss on this account could be estimated at any
moment, and revision of buying prices made
to suit the cabled market reports. A machine-
driven cacao polisher should also be included
in the equipment ; it effects within half an hour,
at a cost of a penny or two, the value of a day’s
work for two men, and should certainly increase
the value of a merchant’s cacao by Is. to 2s.
per cwt. It is time, therefore, that the cacao
merchants abandoned primitive methods and
came abreast. of the times by adopting one
or other of the various time, labour and ‘money-
saving appliances now on the market.

Mr. George S. Hudson 163

Before proceeding to treat the question of
cacao curing in detail I think a few words
would be useful regarding the small cacao
producer’s share in this matter. I refer to
the man who always sells his cacao to the
merchant. Perhaps it is necessary to first
dispel the illusion that the prosperous mer-
chant gets fat on the profits from this trade.
Whatever the result may be elsewhere, it is
‘not so in the West Indies, where cacao buying
yields a very moderate profit in comparison
with the time, labour and money invested in
it. It is more often looked upon by the mer-
chant buyer as a means of remitting money
to Europe at a small profit instead of buying
bank bills at a premium, and the extra ‘turn-
over” of business with the agent in Europe
all helps to grease the wheels of finance. In
referring to the low class of native cacao
throughout the world there is an implication
that the native is the individual to be blamed
for this result. I would not like to become his
champion, but it is only fair to state that, as
matters now stand, the game is all in the hands
of the cacao buyers, and they, by uniting, can
call whatever tune they wish as regards the con-
dition of the cacao when brought to them for
sale within the legal restrictions. It is prob-
able that two nights’ sweating and one day’s
sun would not interfere with the prospects of
turning’ out a good sample, and would give
ample chance of convicting a cacao thief. It

164 The Fermentation of Cacao

may be briefly stated that when one considers

all the difficulties of his case, the small native
grower is not in a position to economically
turn out fine parcels of cured cacao, and if he
were he would not do it.

Practical Estate Cacao Curing.
Picxinc Unrire Pons.

a the valuations of Mincing Lane brokers.

‘Fine Estates” West Indian cacao (exclud-
ie the “fancy marks” of Trinidad and
Montserrat) it is common to find the words
‘part unripe” insisted on and repeated over
long periods. No doubt the same com-
ment is applied to similar cacao from Bahia,
the West Coast (Africa) and St. Thomé. On
examining samples of this cacao, viz., fine
West Indian, there will be found a certain
percentage of the seed (say 10 per cent. to
20 per cent.) that are flat. On “breaking”
these seeds, although the break is more brittle’
and the testa or skin of the bean separates
more easily than that of similar beans of unfer-
mented cacao, yet they exhibit an undesir-
able compact fracture of violet colour unin-
terrupted by the lacune or air spaces found
between the convolutions of the cotyledons. of
higher class cacao. Even the cacao highly
fermented by Dr. Lucius Nicholls’ process
still contains a similar proportion of these flat
seeds. While there is therefore every excuse

Mr. George S. Hudson 165

for the brokers to attribute this flatness to
unripeness, yet I am convinced they are almost
entirely wrong in their diagnosis. Many ex-
aminations of the heaps of cacao pods in the
fields have convinced me that these, as a rule,
on .a well-conducted estate, do not contain
more than 1 to 2 per cent. of unripe cacao, and
further it can be ascertained that this extreme
flatness and solid fracture is a characteristic of
the lowest type of Calabacillo cacao, and is not
to be found associated even with the unripe
beans of higher types. It will therefore only
be just for cacao brokers, buyers and manufac-
turers to absolve the planter from this particular
sin of picking unripe cacao—for although it is
impossible to always avoid picking an unripe
pod, yet even the most ignorant peasant knows.
that such a practice is undesirable—and in
future to attribute this undesirable quality to
the fact of the beans having been picked from
a Calabacillo type of tree.

REMOVAL OF THE PLACENTA IN TIIE FIELD.

I would emphasize the desirability of making
the cacao carriers or basket fillers free the seed
entirely from the ‘fibrous heart” or “ placenta,”
a proportion of which is too often carried in
with the cacao. Where a rotary or vacuum
dryer is in use this becomes almost essential
to economical work, and a little drastic super-
vision and fines at the outset soon accomplish
this object. Failure to observe this involves

166 The Fermentation of Cacao

increased cost of transport, and loss of valu-
able time and labour in the drying house in
‘cleaning ” the cacao.

SEPARATION OF QUALITIES IN’ THE FIELD.

In the economical working of an estate. it
has not been found profitable to separate the
one or two unripe pods and the small propor-
tion of more or less ‘‘ brown” or ‘ black rot”
pods from the general “sweating box”; yet
one cannot but see that a ‘counsel of perfec-
tion” would demand this sacrifice. There can
be no doubt, however, as to the propriety of
‘separating rat-eaten collections of seeds from
the general bulk.

Criollo or Pentagona types cannot be profit- -
ably fermented together with coarser qualities,
the former requiring only three to four days in
the fermenting box, and the latter five to eight
days: apart from this difficulty no one possess-
ing any modicum of common sense would mix
high-class cacao with an ordinary estate lot,
thus reducing the value of the better seed by
perhaps 50 per cent. Separation of these
varieties should occur at planting time, or fail-
ing this in the pod heaps before “‘ breaking.”

MeasvurinG ‘‘ Wer” Cacao.

-For three reasons it is necessary to ascertain
the weight and volume of the cacao as it is
placed in the “sweating” boxes, viz.: (1) To
ascertain the annual yield from each particular

Mr. George S. Hudson 167

field of cacao, (2) to find out if the cost
of picking operations is not .excessive, and
(3) to be in a position to check the. weight: -
of dry cured cacao turned out in comparison
with the amount of raw or “ wet” cacao enter-
ing the sweating boxes. The latter reason
only is germane to this essay. The adoption of
some package of standard measure is necessary,
and, in the West Indies, the North Ameri:
can flour barrel is recommended as a uniform
measure, being cheaply and easily obtainable and
replaceable. Both the head and bottom of such
a barrel are removed, and it is placed, supported
by two short lengths of board which constitute
a false bottom above the uncovered (No. 1)
sweating box. When filled it is easily emptied
by drawing away from underneath it one of the
short-boards, when the contents fall into the
sweating box below. For more accurate meas-
urement it is convenient to theoretically divide
the barrel into twenty-four parts—thus three-
fourths of a barrel would be 38, half a barrel 42,
and one quarter of a barrel 5. Subdivision may
be carried further by a knowledge of how many
cacao baskets go to a barrel: thus if four baskets
usually fill the barrel, half a basket would equal
#, of a barrel, somewhat less than half a basket
would count as #,, and a lesser quantity just
covering the bottom of an ordinary cacao basket
would be equivalent to 3, of a barrel. The
barrel is generally ‘‘heaped” to the natural
angle of wet cacao, forming a mound the centre

168 The Fermentation of Cacao

of which is some 6 in. higher than the top
circumference of the staves. Such a “heaped”
barrel would contain an approximate weight of
300 |b. of cacao; but the factor of weight is far
too uncertain a one to be used in checking wet
cacao, for it is obviously a hopeless task to
accurately weigh a material from which juice is
continuously exuding. A delay of a quarter of
an hour would make an appreciable difference
in the weight of freshly picked cacao, but very
little difference in its bulk: therefore, in its wet
state, bulk or volume is a preferable measure
to weight.

Ratio or Uncurep To Curep Cacao.

Some few years ago the Agricultural Depart-
ments of the West Indies were concerned in
arriving at a true ratio in the weights of
uncured to cured cacao, and the results of
experiments towards this end were published
from the Agricultural Stations of Trinidad and
Dominica, and other sources. They all varied
considerably, but I am convinced that they
were all honest attempts to create a fixed
ratio. They were equally correct and equally
incorrect, for a fixed ratio under all conditions.
of air humidity and soil moisture, if attained
after many years’ experiments, would partake
so much of the nature of a general average as.
to be useless for everyday work.

Where the flour barrel measurement is.
used the following ratio can be relied on as

Mr. George S. Hudson 169

a result of over twenty years’ records by the
writer. As just stated, a barrel holds approxi-
mately 300 lb. wet cacao to start with :—

One barrel wet cacao picked during the wet
season equals 100 |b. to 106 1b. dry cured cacao.
One barrel wet cacao picked during medium
weather equals 106 Ib. to 110 |b. dry cured cacao.
One barrel wet cacao picked during dry season
equals 110 Ib. to 120 lb. dry cured cacao.

These records are based on returns from a
rather clayey soil, and a type of cacao in which
yellow Amelonado predominates ; it is probable
that a somewhat better ratio would be obtained
from a lighter soil, even although the rainfall
(about 100 in, in this case) were heavier.

In three experiments to determine approxi-
mately the percentage of weight of cured to
wet Amelonado cacao, care having been taken
to include all the fruit juices, the following
results were obtained :—

Quantity experimented with, 200 lb. wet
weight, in all three cases.

(1) Fermented seven and three-quarter days,
maximum temperature 113° F., loss in sweat-
ing 55 lb., curing and drying 79 Ib., leaves
66 lb. dried cacao.

(2) Fermented six and three-quarter days,
maximum temperature 109° F., loss in sweatin
46 lb., curing and drying 794 lb., leaves 744 lb.
dried cacao.

(3) Fermented seven and three-quarter days,
maximum temperature 106° F., loss in sweating

170 The Fermentation of Cacao

54 lb., curing and drying 72 Ib., leaves 74 Ib.
dried cacao.

The average dry return from these three lots
of 200 Ib. wet cacao was nearly 72 lb., or a per-
centage of 36 per cent., a result considerably
lower than that hitherto generally accepted.
Taking the average weight of a ‘barrel of wet
cacao at 300 lb., and the average return of dry
cacao from it at 110 lb., the result works out
very close to 36 per cent., and confirms the
above experiments which were conducted in
mediumly wet weather.

In four experiments of fermenting and
curing Pentagona cacao, the fermentation was
thoroughly effected within four days, and the
net return of dried beans varied from 274 per
cent. to 29 per cent. of the wet cacao treated.

Is FERMENTATION PROFITABLE?

In order to ascertain this point, two lots of
100 Ib. each of wet cacao were cured without
any fermentation beyond placing them to drain
for one night in a sweating box. After sun
drying in the usual way the average result
showed 39 per cent. of dry cured cacao, or
*3 per cent. more weight than in the case of
fermented cacao. Taking the value of the
unfermented cacao at 50s. per cwt. (June, 1911)
and of “Fine Estates” fermented cacao at
56s. per cwt., we find the 39 lb. of unfer-
mented to be worth 17s. 6d. gross, and the
36 lb. of fermented to be worth 18s. gross,

Mr. George S. Hudson 171

showing a profit of 6d. per 100 lb. wet in
favour of fermented, or about ts.- 6d. per
ewt. dry cured. The actual expense of curing
unfermented cacao is not smaller than that
incurred in thoroughly fermenting, polishing
and curing, for owing to the toughness of the
cuticle of unfermented cacao,this product takes
at least seven days more to dry than fer-
‘mented beans, and the cost of drying, labour
and space for this period must be taken into
the calculation. These experiments, therefore,
confirm the profitableness of fermenting cacao,
as by doing so the planter obtains a better
product of greater value.

FreRMENTING RECEPTACLES.

If one may credit the literature on this sub-
ject, it would appear that almost every class of
receptacle—from a hole in the earth to the
most highly ingenious sweating boxes (one of
which is evidently “designed to “cook” the
cacao with a uniform temperature of 140° F.)—
is used in one part of the world or another.
In actual estate practice there are, however,
very few modifications in fermenting boxes,
and it is noticeable that the larger the estate
the more simple are the receptacles. For
estates producing less than 300 bags per annum
a row or (incomplete) circle of seven or eight
wooden boxes, each capable of holding a
maximum day’s picking, is all that is necessary,
provided drainage is arranged for the juice

172 The ‘Fermentation of Cacao

from the first two boxes to be run off; curved
glazed earthenware tiles embedded in concrete,
to form an open channel, being best. Open
concrete drains are usually provided, but the
acid in the undiluted juice eats into the con-
crete in a few years. It is advisable that
the boxes be raised 18 in. from the ground
for drainage purposes in the first two boxes,
and also in the case of the last one or two,
so that baskets may be placed under the
exit to facilitate the removal of the fer-
mented cacao to the curing house. It is
necessary to remember that the weight of a
full box of cacao is not insignificant, and one
must therefore provide: adequate support be-
neath. In boxes with a capacity of not more
than seven barrels of wet cacao (say 2,000 Ib.).
good t-in. boards may be used without any
frame-work. In calculating the capacity of
sweating boxes an allowance of 6 cubic feet or
a little less per barrel of wet cacao (= 300 lb.
wet or rro lb. dry) will be found ample space
for all the boxes, as the bulk of the fermenting
cacao does not greatly vary. Beyond seven
barrels ‘capacity it would be advisable to use
uncovered concrete tanks, lined with wooden |
boarding or slate, and whether wooden or

concrete boxes are used the dividing partition
between the boxes should consist of loose
boards lifting out of a grooved slot to facili-
‘tate “changing” the cacao from one box to
another. In the last one or two boxes of a

Mr. George S. Hudson 173

series (which should never be less than six
and preferably eight) a frontal sliding door,
about 12 in, to 15 in. wide, should be arranged
to extend to the bottom of the box to serve
the double purpose of ascertaining the bottom
heat of the cacao (as frequently this becomes
cold, discoloured and mildewed, while the top
is still warm and of a desirable colour) and
of expeditiously emptying the box. In shape
no advantage is gained in departing from the
square. Wooden covers are unnecessary as
regards fermentation, but are frequently used
with padlocks to prevent theft; for fermenting
purposes the best cover is a thick layer of
wild plantain or banana leaves. Devices,
other than that mentioned, for facilitating
“changing” of boxes are not recommended.
Iron rails are in time affected by the acid
juice, yet it is questionable whether any
economic substitute can be found for them in
building wooden boxes. In considering the
building to contain these boxes the following
recommendations are made: ‘“ Ruberoid” or
some other “Giant Paper” roof, with full
boarding underneath. Concrete or tile floor.
Steep concrete drains communicating with an
adjacent watercourse’ if vinegar is not to be
manufactured, the smell of decaying cacao juice
being most objectionable. Plenty of head room

1 This strikes me as tending to lead to friction on
other estates or oe ae where the polluted water
‘may pass.—H. H.

174 The Fermentation of Cacao

over first box to facilitate measurement of
cacao and to ensure cleanliness and order inside
the building, and an arrangement whereby
carriers of cacao may deliver their load to the
sweating box without entering the building.
An ideal system of cacao-curing buildings

under one roof would be..—

Passage aad

- to empty wer
6 7 6 5 4 a =

Stain
Cacao in
/ Fi
a ae ua box
Sweating Boras
(Door “X TX , UMeain___ Door|
Exit for Fermented Cacao

Platform tor cleaning Cacao é charging spare

/

VacuumDryer trays 2 ny :
u . 21
i) 2 ie ae
acu
e lew > Pt
g 3 - or g |:
& s Engine Machine A
q . Oryer
"Door
bagging ¢ Weighing Room
Door

In such a building, all under lock and key,
with clean concrete floors, and secure from
adverse weather conditions, two charges of
cacao per ordinary working day (or three
charges working overtime) might be passed
through the vacuum dryer and polisher, and each
day’s output from the sweating. boxes. bagged?

Mr. George S. Hudson 175,

and sewn up the same day.’ Economy would
be exercised in time and all the advantages
secured that this saving entails, such as land
space, expenditure, supervision, labour, pilfer-
ing, and wastage. The building need not be an
expensive one ; its capacity to “deal with a crop.
would be in proportion to the size of the sweat-
ing boxes and the vacuum or machine dryer, and
“it should turn out the highest possible grade of
cacao in the most unfavourable climatic con-
ditions. Vacuum and machine drying and
polishing will be dealt with in their place in
this essay, also the non-advisability of washing
or grading cacao.

State SweaTING Boxes.

Before leaving the subject of sweating box
construction it will be useful to mention some
experiments on the writer’s part to provide
a smooth, continuous and more cleanly surface
for the interior of sweating boxes than wooden.
boards. It is obvious to anyone with experi-
ence in this matter, and Dr. Nicholls has also
commented on it from a bacterial point of view,.
that the worn surface and crevices of boards
form an ideal breeding place for mildew and.
other undesirable germs which persist and
multiply even when the boxes are empty.

‘No matter how pressed for time, however, the cacao-
must be absolutely cooled before being bagged, other-
.wise it will develop exterior. moulds.—H. H. S.

176 The Fermentation of Cacao

Also, it is difficult to keep such a surface clean
and free from larger insects, cockroaches, &c.,

&c. In considering what acid- -resisting smooth
surfaces could be substituted for wood, the
writer has passed over such materials as
glazed eéarthenware, enamelled iron and
‘“Ruberoid” in favour of planed slate. In
order to test the properties of this material
he constructed a slate sweating box of 1 in.-
planed slate with sloping floor and_ liquor
exit. It was rather elaborately made. with
rounded corners and acid-resisting cement for
joints, and was consequently more expensive
than it need have been. However, planed slate
in slabs is not an expensive material: I refer
to the sort of thing supplied for old-fashioned
public urinals. 1 have carefully experimented
with this box, contrasting temperatures with
wooden boxes, and am quite satisfied that in
slate we have an ideal surface to make perma-
nent linings for the interior of concrete sweat-
ing boxes in place of the loose wooden
‘casings now used on most large cacao estates.

Litharge mixed with liquid glass solution
makes a suitable cement for joints. Possibly
4-in. or $-in. thick slabs would serve under
these circumstances, but I am afraid slate
would be too heavy and breakable a material
for the sliding up partitions between the
boxes ; however, the lower 18 in. of this inter-
partition should not-be removable and could
be made of slate while the upper part could be

Mr. George S. Hudson 177

made of wood lined with ‘“ Ruberoid” as a
single panel.

FERMENTING Cacao.

The biological, entomological and chemical
aspect of this process is fully dealt with by
Dr. Nicholls in the next chapter, in this one the
practical everyday side of the subject is treated.

The following axioms are submitted as
having been borne out by the writer’s ex-
periments :—

(t) The higher the temperature attained and
maintained for some days by primary natural
fermentation, the better the class of cacao
turned out. (The maximum limit of tempera-
ture attained by the writer’s experiments was
rio” F,)

(2) The addition of Dr. Lucius Nicholls’
pure ferment and yeast food solution induces
a higher and more prolonged beneficial fermen-
tation.

(3) The daily “changing” of cacao from
box to box by a wooden spade, thereby trans-
ferring the bottom seeds to the top, is most
necessary to attain the best results.

(4) Beneficial fermentation ceases as soon
as the bottom of a box falls belows 100° F.

(5) The larger the quantity of cacao fer-
mented the quicker is a high temperature
attained and lost; but small quantities, while
requiring a longer period, can be fermented
just as efficaciously as large.

12

178 The Fermentation of Cacao

(6) The preservation of heat and moisture
by a thick leaf cover is a most necessary part
of the process, but where a pure ferment is not
added, the cover can be beneficially omitted
from the first and second boxes to allow the
“cacao fly” freer access to the beans to deposit
fermentation germs on them.

The actual process of work in the sweating
house is small and may be described as follows:
The current day’s picking of wet cacao in-
variably goes into No. 1 sweating box, and
for the sake of clarity we may assume the
picking commences on Monday. On Tuesday
morning Monday’s picking is overturned into
No. 2 box, leaving No. 1 box empty to receive
Tuesday’s picking. On Wednésday morning
Monday’s picking is again inverted into No. 3
box, Tuesday’s picking into No. 2 box, and
No. 1 box is always kept free to receive the
current day’s picking. This process is con-
tinued until Monday’s picking reaches the fifth,
sixth, seventh or eighth box, and the bottom
temperature is found to be rapidly declining
when it is removed from the sweating box to
the drying house. Where large quantities of
cacao are fermented under ‘‘ Fine Estates”
conditions of curing (without the addition of a
pure ferment), the first day’s picking, say
Monday’s, will generally come out (from the
sixth box) on Saturday morning, and is not
unusually the worst fermented batch of the
picking owing to the boxes being “ cold’”—

Mr. George S. Hudson 179

which in scientific language means “ sparsely
inoculated with beneficial ferments and largely
inoculated (from the sides of the ‘clean’
boxes) with moulds and mildews.” The first
lot of cacao, if sufficient in quantity, can, at
the expense of a day’s delay, eventually attain
a temperature that defeats the mould and
mildew, and this high temperature and acetic
acid of the second and subsequent batches
completely routs these undesirable guests, and
thus completes their fermentation in one day
less than the first batch. If, however, the
bottom temperature of the last box is allowed
to fall below 100° F. the moulds and mildews
immediately reappear, and this will mean dis-
coloured, dark, ugly cacao already infected with
mildew germs. With sun drying in unfavour-
able weather, mildew is most frequently com-
municated from the cracks in the drying floor
to the moist seed. It is easy under these
circumstances to perceive the advantage of
maintaining thorough cleanliness in the interior
of sweating boxes, of doing away with
covered boxes and dark corners, and adopting
single-piece sides of a smooth material that
will not harbour spores.

It is necessary to maintain perfect drainage
of the acid juice from the first two boxes.
This is sometimes attained by a movable
wooden grid or grating with spaces that retain
the smallest seed while allowing the escape of
the liquor. For wooden boxes a simple .and

180 The Fermentation of Cacao ,

efficacious plan is to pierce the. bottom with
a sufficient number of 4 in. auger holes. For
concrete boxes a bottom sloping down to a
long narrow slit of an exit is preferable.
Much inadequate fermentation of cacao is
due to an insufficient and carelessly arranged
leaf cover. It is a simple matter to observe
with a thermometer the loss in heat that takes
place in five minutes by the removal of the
leaf cover from a box of strongly fermenting
cacao; such a loss immediately reacts on the
fermenting organisms, lessening their beneficial
action. Of course, heat is only a symptom of
beneficial fermentation, but it is the most
important symptom and its readings spell
either success or failure. The most suitable
covering for sweating boxes is the leaf of the
wild plantain (Heliconia bthaz), commonly
called Bahsszer in French patois, Other
leaves used in the West Indies are banana,
plantain and tania. When fermentation proves
difficult and incomplete it is much assisted by
lining the bottom and sides of the box with
wild plantain or banana leaves. As the heat
generated in the first and second boxes is
generally not much in excess of the atmo-
spheric heat, the omission of the leaf cover from
those boxes is recommended as allowing free
access to the ‘‘cacao fly” (described by Dr.
Nicholls), and thereby ensuring a more com-
plete inoculation of the fermenting yeasts.
Another most important factor is a thorough

Mr, George S. Hudson 181

and daily “changing” of the cacao. Although
I had followed this practice for over twenty
years, yet I never grasped its full significance
until 1 instituted a thorough examination of
fermenting temperatures. In one or two in-
stances, through carelessness or over-pressure
of work, the sweating box attendant for a
single morning omitted to “change ” the spare
fermenting boxes with which I was experi-
menting: in every such case there was a
marked loss of temperature. Even when
‘‘changing” had been conscientiously per-
formed, plunging the thermometer, say twenty
times, in different parts of a fermenting mass
of cacao.on the third or fourth day, when high
temperatures are commencing, would result in
six or seven different readings, with perhaps
as much as 5° F. difference between the maxi-
mum and minimum; this demonstrates that
fermentation does not take place as a uni-
form, continuous process throughout a box, but
rather as the result of numerous independent
colonies of yeasts, all working towards the
same object but with varying results. It was
made amply clear to me that although the
“breaking bulk” process known as ‘“ chang-
ing” resulted primarily in a loss of tempera-
ture, identically the same as occurs from the
removal of the leaf cover, yet within a few
hours the thorough mixing and diffusion of
the fermenting yeasts results in the tempera-
ture rising much higher than was the case

182 The Fermentation of Cacao

when the box had been left “unchanged.” It
is a necessary part of this process that the
bottom layers of cacao are always inverted to
the top and wzce versa. A wooden spade made.
for this purpose should always be used ; not
only is it lighter and more convenient to
handle, but the contact of fermenting cacao
with iron results in a stain on the cacao’ seed.

. NeGATIVE EXPERIMENTS.

Before leaving the subject of fermenting, it
may prove useful to those interested in this
matter to mention two experiments that were
tried with unsuccessful results.

The first was simply pouring back again and
again over the cacao the exuding liquid that
oozed from the bottom of the box. There was
no sign of increased or prolonged fermentation
resulting from this procedure. The maximum
temperature attained was 109° F. with 300 lb.
of wet cacao, and it commenced to fail on the
sixth day.

The second experiment was based on the
assumed possibility that fermentation was
prematurely checked by the production of
acetic acid. It is a common phenomenon with
quickly multiplying micro-organisms that, as
a result of their rapid labours, their: environ-
ment is self poisoned by the production of
some substance which, as the quantity in-
creases, becomes inimical to their welfare and
eventually destroys them. As acetic acid. is

Mr. George S. Hudson 183

produced in quite perceptible quantities by
cacao fermentation, an attempt was made to
neutralize the acid by spraying the cacao with
some cheap alkaline solution, such as dilute
lime-wash. About 300 lb. of wet cacao were
experimented with, and control experiments
were also conducted under the same conditions.
The result was that the temperature was
lowered throughout the course of the experi-
ment by about 2° F. (reaching.a maximum of
111° F,), and that fermentation was not pro-
longed beyond the usual time. The resulting
sample showed a lighter colour than ordinary
well fermented cacao, but otherwise had a good
“break” and taste. In unwashed samples
the presence of lime was perceptible on the
exterior of the seed. Some 5 gallons of
lime-wash, composed of, sixteen parts water
to one part lime, were sprayed on during five
days.

TEMPERATURES WITH ORDINARY FERMENTING
METHODS.

The following table gives a fair idea of cacao
temperatures under ordinary estate conditions
of fermentation. The average air temperature
was 78° F. and the average humidity 79.
The boxes were changed daily and readings
taken at 7 o’clock each morning.

It is noticeable that the smaller quantities
require more time to complete the process, but

184 The Fermentation of Cacao

it does not follow that a more moderate fer-
mentation continued over a longer period is
not as efficacious as the higher temperatures
and shorter period of the large lots.

Cacao TEMPERATURES—FAHRENHEIT.

iday ane a 2. athe 53 days Hes ale Quant). Box
° ° ° ° of}, ate Le ° ° Ib, :
(1) 85} 96} 110/117 | 114 | 106 bottom j —|— | 2,000 | Wood.
(2) 84| 95|I10/112;115]| 114 top ...| — | —]| 2,000 55
(3) 69| go|itr2/t19/ 117} 15 top ... | —|— | 2,000 a5
(4) 87 | ro5} 115} 116/117) 184top ... | — | — | 2,000 39
(5) 88)106/116/119/116| 116top ... | —j—]| 2,000 35
(6) 76} 81} 90}109!108| 108 .. | 102] — 200 5
(7) 79; 90] 94| 101] 117] 11g sis fab _ 400 | Slate.
(8) 78} 87| 88]}10£} 109] 108 vad 705 94 300 5
op

TEMPERATURES WITH Dr. NICHOLLS’ FERMENT
- AND SOLUTION.

Conditions identically as above.

Cacao TEMPERATURES—FAHRENHEIT.

i day nes a a Pt ats a ae are ane a Box
eS es
o o ° fe} se) ° ° ° ° ° Ib.
(9)*71 | 82 | 87 | 108] rr2|*rr3/ 114] 113] t10] 96 300 «=| Slate.

top
(10) 80) 88 | 96 | 164 /*108) r1r/ 113 108 | — — 200 | Wood.

Mr. George S, Hudson 185

In these two experiments the ferment and
solution (from }? pint to + pint in each case)
was sprinkled on the cacao on the three days
marked with asterisks; on two of these
occasions the temperature was undoubtedly
failing, but recovered immediately after the
addition of the yeast culture and its food
solution.

The cacao resulting from Experiment No. 10
showed the effect of fermentation by this
method ; it is probably worth 1s. to 2s. per
cwt. more than that produced by the other
experiments. Unfortunately, a prolonged spell
of exceptionally wet weather prevented a
favourable sample being obtained from Ex-
periment No. 9.

Two other experiments, in adding to fer-
menting cacao pure cultures of two other
varieties of wild yeasts, isolated by Dr.
Nicholls from fermenting cacao, did not yield
such good results as those detailed, and it was
therefore demonstrated that the variety of
yeast used in Experiments g and 10 was the
best.

It is obvious, if Dr. Lucius Nicholls’ method
of fermenting with a selected pure yeast is
.to come into general use on cacao estates
and with cacao-buying firms, that the busi-
ness of producing and distributing this yeast
at a nominal price must be taken in hand
by the Government Agricultural Departments
now existent in almost every cacao-producing

186 The Fermentation of Cacao

country. This paper will probably have
demonstrated that this scheme for the im-
provement of cacao fermentation at least
merits a continuance of experiments by the
mycologists of the different Agricultural De-
partments, and that in the event of their
conclusions showing the desirability of pure
yeast inoculation (which process in kindred
trades where fermenting is practised has en-
tirely superseded all other methods) a very
strong case will be established for the cheap
distribution of the materials recommended.
It is also greatly to be desired that investiga-
tion on this subject be continued by experts
interested in tropical agriculture, for it is not
contended that the last word has, by any
means, been said on the subject.in this essay.

DrvyiIna.

As shown in previous figures, some 25 per
cent. of weight is evaporated during fermenta-
tion, and about 39 per cent. during subsequent
curing, leaving a residue of about 36 per cent.
cured cacao (of ordinary type). These figures
are only approximate, and are quoted merely
to give a clear view of the process.

It is suggested here that the improvements
in cacao curing which may be effected will lie
principally in the direction of :—

(1) The constant production of a high-class
sample irrespective of weather.

(2) Economy in working expenses.

Mr. George S. Hudson 187

(3) Economy in utilizing a limited labour
supply.

(4) Saving in wastage and pilfering.

(5). In greatly expediting the whole process,
thereby saving both time and money.

The expense of fermenting cacao efficiently
stands in a very small proportion to the entire
cost of. curing. Taking the actual labour
wages for curing cacao as costing 1s. 6d. per
cwt., it is probable that of this amount one
penny per cwt. would cover the cost of fermen-
tation. It is obvious, therefore, that when
studying economy the cost of fermentation
stands as a negligible quantity in comparison
with drying, polishing, &c.

Drying appliances and methods are quite as
numerous as the different types‘of fermenting
boxes, but in actual estate practice quite 90
per cent., if not more, of the world’s cacao
output is dried in the sun. Some few estates
combine sun drying with a hot-air chamber for
wet weather and to enable them to continue
drying during the night in times of crop
pressure, and within the last ten years many
of the larger estates in the West Indies have,
at a cost of £1,000 to £1,500, established
rotary drying mae Wines: whok force heated air
through the constantly agitated cacao, com-
pleting both the curing and polishing pro-
cess in thirty-six hours’ continuous work-
ing. A fourth method worthy of notice is
vacuum drying, which | believe has only

188 The Fermentation of Cacao

been experimented with on one or two cacao
estates throughout the world. I shall deal as
briefly as possible, without ‘‘scamping” the
subject, with these different methods, en-
deavouring to indicate what I venture to think
are the best types."

‘Sun Drvine.

To a superficial observer the thought will
easily occur, that, “surely in a tropical climate
no drying power could be cheaper than the
sun.” It is necessary, however, not to over-
look the fact that in the average cacao
climate + in. of rain per twenty-four hours,
or gO in. per year (that is, roughly, four
times the rainfall of London), is the usual
precipitation ; further, that in most parts of the
cacao- producing world the period of heaviest
rain occurs identically with the period of
heaviest pickings, and then it not infrequently
happens that rain falls almost incessantly for
a week or more. In the absence of sun for this
period, and with an atmosphere in which the
hygrometer readings show saturation point
for days at a stretch, it may readily be believed
that the most perfectly appointed sun-drying
house (commonly called ‘‘boucan ” in the West
Indies) fails to comfort its possessor whose
fermenting boxes keep on delivering cacao to

1 Since these notes were written, other processes
have, of course, been introduced, or at least discussed.
—H.H.S. ’

Mr. George S. Hudson 189

the drying trays, where it accumulates, blackens
and commences to smell abominably while the
powerless planter paces his verandah and
scowls at the weather. It is a situation known
to every strenuous cacao planter, and in time
we learn to take it philosophically—or arrange
for hot-air drying. I have not led up to this
situation with the view of inciting sympathy,
or entirely to decry sun drying, but rather to
suggest that if fermentation can be continued
during this weather, beyond the usual five or six
days, and continued to nine days or more by the
help of the inoculation of active yeasts and a
food solution for them sprinkled on the cacao,
the situation would lose much of its depressing’
influence, and the produce would be rather
benefited than depreciated in value.

Sun drying, however, as an auxiliary to
more modern methods, and as a standby in
case of accidents and machinery breakdowns,
is most useful, and, by reason of the large
amount of capital already invested in
‘“‘boucans,” cannot be disregarded. Cacao
planters are somewhat conservative, and it is
probable that on small estates sun drying will
always be the method of curing employed.

The type of ‘‘ boucan” recommended is the
large, simple, sliding roof pattern, so often seen
in Trinidad, but with a smooth concrete floor
and side border in place of the usual pitch pine
flooring and sides. The flooring should not be
elevated more than is necessary from the land.

190 The Fermentation of Cacao

Compared with the type of “boucan” con-
sisting of a number of trays on wheels, the
sliding roof pattern may not be the cheapest
house to build as regards providing so many
superficial feet of drying space for so much
money, but it will be found the cheapest house
to work, and that point is infinitely more
important than initial cost. The roof should.
be covered with light galvanized iron sheets,
28 gauge. The span should be from 16 ft. to
20 ft., and the length should be just as long
as will allow of one man pushing each half.
roof to and fro easily. This will depend on
the skill in construction, lightness and trueness
of the roof, and the iron rails and style of
wheels used, 50 ft. length being taken as a
minimum; the outside rails should be sup-
ported on concrete pillars. This type of
‘“boucan” may be multiplied to meet the
needs of a large estate. The advantage of
economy in working is all in, favour of the
large floor space; small trays involve too
much labour in constantly shifting the cacao
from one tray to another, to make room for
new batches as curing progresses, and also
involves too much dropping of seed on the
ground in the process. It is quite impossible
to efficiently deal with mildew on a wooden
drying floor, consequently batch after batch
of cacao coming from the fermenting boxes
receive their inoculation of mildew, which lives
on the skin of the seeds, until more or less

Mr. George S. Hudson 191

efficiently removed by polishing, and even that
does not always prevent this blemish from
sometimes penetrating to the interior of the
seed. It would probably be useful to follow the
procedure used in military stables, and incor-
porate an appreciable quantity of powdered
sulphaté of copper in*the upper ‘rendering ”
of the concrete floor. Where a wooden floor
already exists, a covering of very thin copper
sheeting, with as few joins as possible, would
probably prove advantageous. The idea is to
provide a surface free from cracks, in which
mildew spores cannot persist, and which can
be effectively cleansed with a bucket of water
and a hard broom.

As to the space required per 100 bags of
cacao, no hard and fast rule can be adopted.
Some estates get more than half their crop
within a few months of the year,’ other estates
with lighter soil-and younger trees divide the
crop much more equitably throughout the year.
Again, some estates near the sea coast or on
flat, open Jand get much more sun and less rain
than other plantations situated up in the hills.
Without auxiliary artificial heating probably
5 superficial sq. ft. per cwt. of dry cacao
produced would not be excessive. With an
auxiliary hot-air chamber or machine, probably

1 The Gold Coast returns, for instance, show that out
of an export of about 40,000 tons cacao, some 28,000
tons, or 70 per cent., were exported in the four months
November-February.

192 The Fermentation of Cacao

3 ft. per cwt. would suffice. Where drying
conditions are favourable these figures may be
reduced by about 25 per cent.

Briefly described, this well-known sun cacao-
drying process is as follows. The fermenting
boxes are examined about 6 a.m., and if the
cacao is fit to go out on the “ boucan” it is
carried in baskets over the short space separat-
ing the “boucan” from the fermenting house
and deposited on the drying floor or trays. It
is then raked over until the seeds lie two or
three deep. When this work has to be done,
one of the end pieces of a barrel head, in shape

gaa

THE PALETTE.
Made from the end piece of a barrel head.

describing a quarter circle (see illustration),
is mounted on a rough straight handle of con-
venient length, and the straight edge is used
to rake the seeds smooth. In order to allow
the bottom of the floor (now completely
obscured by damp cacao) to dry out and
become warm in the sun, the cacao is, at half
hour intervals during the first morning, heaped
into small ridges a few inches apart, for which
purpose the sharp points of the quarter circle
are used, exposing each time a different surface
of the floor between the ridges. When the
cacao is more thinly deposited on the drying

Mr. George S, Hudson 193

floor, this process of ridging is unnecessary,
but the seeds are continually being turned by
hand or some wooden instrument, such as the
“palette” shown on p. 192. It is impossible
to get too much sun on the cacao during the
first day or two’; the more sun and the more
frequently the cacao is turned the better the
sample, provided fermentation has done its
part. The cacao should be “picked over”
during the first day, all ‘placenta,’ empty
seed skins, pieces of pod, leaf and other
foreign matter removed, and all adhering
beans separated from one another. On the
morning of the second day, unless conditions
of sun, evaporation and mildew infection
have been very favourable, an almost im-
perceptible film of mildew is present on
the seeds which later on becomes quite un-
mistakable. On the morning of the fourth
day “dancing” or ‘ polishing” is generally
done, which process, as described later on,
removes the mildew more or less efficiently,
and substitutes an attractive gloss. Another
three to four days’ good sunning with the
cacao, frequently placed four to five seeds thick,
completes the drying, although quite frequently
in unsettled weather the entire process of

1T always found it better to close the house from
r1—2 during the first day, and from 11—1 the second
day, as the excessive heat on the beans fresh from the
sweating-box caused them to shrivel and go “ lean.”—
H.H.S.

13

194 The Fermentation of Cacao

drying occupies a fortnight or more. Of
course there is thorough protection from rain
during the whole of this period. The test of
thorough drying is made by breaking a
number of seeds across the thumb-nail and
observing the condition of the heart of the
seed. If this appears slightly lighter in colour
than the rest of the seed, or shows signs of
moisture on the indentation of the thumb-nail
into the centre of the seed, then further drying
is required. On the other hand it is easy to over-
eure cacao, losing thereby considerable weight
with no corresponding advantage of increased
price. A good easy “break” or fracture across
the thumb-nail is the distinguishing mark par
excellence of well-fermented cacao: it implies
a certain degree of plumpness, of air spaces.
between the convolutions of the cotyledons,
and an easy separation of the outside shell
from the kernel—all of which tell of thorough
fermentation. For the average “fine estates”
cacao a_ well-polished mahogany colour Is.
esteemed, as showing thorough fermentation,
but it must not degenerate into black. For
higher class cacaos, such as Criollo and
Pentagona, a more attractive red, z¢., more
of a cinnamon tint, may be aimed at.

Artificial Drying Apparatus.

“WHITFIELD SmirH” Hort-atr Dryer AND
irs MopiIFIcaTIONS.

Under this name I refer to the drying

Mr. George S. Hudson 195

arrangement erected at the Botanic Station,
Dominica, by the Imperial Department of
Agriculture for the West Indies. Its idea
originated with Mr. Whitfield Smith, now
Commissioner of Carriacou. As erected at
Dominica, the building consists of a large
open shed covering an inner wooden building
containing six large cacao trays on wheels and
rails} arranged in three planes of two trays
each, with an outer extension of iron rails
whereby the six trays can be pulled out and
their contents thoroughly turned over and
picked over without danger of wetting from
rain. There is, however, no arrangement by
which sun heat may be utilized. The interior
building, with its tray shutters, is made air-
tight as far as possible, and at one end hot
air is led into the lower plane of two trays from
a No. 28 iron “Comet” stove (made by the
J. L. Mott Iron Works, 84, Beckman Street,
New York—cost about $40); this hot air
is confined to the lower plane by a ceiling
until it reaches to within 18 in. of the end
of the building, when this space is left open in
the ceiling to allow its ingress into the second
or middle plane of two trays. The ceiling
above this middle tier is also closed to within
18 in. of the opposite end, thus forcing the
hot air to travel over and under the trays, and
the process is repeated in the top plane, at the
further end of which is placed an 18 in.
Blackman ventilating fan (cost about £5,

196 The Fermentation of Cacao

without driving wheel), worked by hand power,
which assists materially in drawing the heated
air through the building. The driving wheel
should be 5 ft. in diameter, with a central
grindstone handle, and built locally of wood—
lead being added to the driving rim. The
following rough sketch of the inner building
may assist in giving a clearer idea of the
process.

In the original idea, as explained above, it

fan ar

E Tray. =}+—L ray J

Cethng: =)
( Tray a le Tray i}

Smoke stack

Ceiling
[ Tray ime Tray ]

Driving |\wheel

Plan of the ‘* Whitfield Smith” Hot-air Dryer.

has not been largely followed in the West
Indies, although it has many advantages. _Its
weak points are expensiveness in labour, fuel,
and supervision, taking into consideration
that it would probably take three to four
working days of ten hours each to completely
dry a charge of cacao, and that at least two
men would be required, and about one cord of
firewood, value 4s. to 8s.

Mr. George S. Hudson 197

The writer has adapted the following modi-
fication of the above plan to a portion of an
old-fashioned sun-drying ‘‘boucan,” with a capa-
city of six tiers of four trays each, or twenty-
four trays in all. The interior compartment of
eight of these trays (7.2, two tiers) has been
made air tight (with double walls filled with
sand), and fitted with specially tight shutters
and hinged steel rails that obviate the neces-
sity of any rail hole in the shutter, yet allow of
the trays being run out into the sunlight when
the shutters are removed and the hinged rails
swung into position. It was found that a single
ceiling in the centre of the tier broken by an
18-in. space at the end furthest from the
stove acted better than a ceiling over each
plane of trays. The diagram of the “boucan”’
is, roughly, thus:— =’

Adapted to both sun
for sun ) ary ing only ad hot air drying
(Ferl__Ter2__‘Ter 2 Tier "Tier 5 Tier 6

Blackman fan

oa) os ee eee

SS Driving wheel

Cewi7
tof fan

—, ~\ Coo | Od

Mr. Hudson’s modification of the “ Whitfield Smith” Hot-air.
Dryer.

This arrangement must be regarded as an

/

1 98 The Fermentation of Cacao

additional help to drying and an insurance
against the ‘‘ weathering ” of cacao during rush
of crop and very wet weather. It is unneces-
sary to use it more than two or three months
in the year and then seldom in the day time, but
generally between the hours of 4 p.m. and
10 p.m. The tray flooring consists of copper
wire mesh with Zin. apertures supported by
wooden battens, and the hot air chamber is
principally used for drying cacao quickly after
polishing, thus retaining its gloss and attrac-
tiveness. Its recommendation lies principally
in the fact that the two tiers adapted to hot air
drying are quite as capable of taking advantage
of sun heat and wind evaporation as the
remaining four tiers of the ‘“boucan,” and the
change to hot air drying is effected without
shifting the contents of the eight trays. This
factor, allied to the small cost entailed in the
arrangement, constitutes its advantage and
economy. The trays each measure 12 ft. by
6 ft. Twomen are employed in the evenings
to tend the stove and turn the driving-wheel
of the fan at a cost of 6d. each. Three to four
cords of firewood prove sufficient to deal with
100 bags or more of cacao. .In the morning it
is usual to find the cacao quite warm, although
fan and stove operations have been suspended
since 10 p.m. The maximum heat advocated is:
130° F., but usually 110° will be found sufficient.
I do not advocate this scheme as by any
means a perfect one, but it is. economical to

Mr, George S. Hudson 199

apply to existing “boucans,” cheap in working
and satisfactory in results. This statement
does not by any means obviate my objections
to the relative expensiveness of labour on
‘boucans” containing a series of small trays,
but only illustrates how to make the best of
existing sun-drying buildings.

Rotary Hot-arr DRYERS.

For large estates, producing over 500 bags,
the ‘‘Gordon” Machine Dryer (Messrs. John
Gordon and Co., 9, New Broad _ Street,
London, E.C.) seems to have almost a clear
field and no competitors, although very many
of the most intelligent planters prefer to rely
on hot-air chambers of varying construction,
but all embodying the same principle as the
“Whitfield Smith” chamber, or very nearly
approaching it. One can only imagine from
the expensive plants of “ Gordon” Dryers one
sees being installed on large properties at
Grenada, Trinidad, and elsewhere, that these
machines give satisfaction when large crops
have to be dealt with. The plant, including
buildings, varies in cost from £350 to over
41,000, and is capable of treating from four to
thirty bags of dry cacao in one charge with
continuous working of thirty-six hours.1 The
sample turned out is an attractive one, as a

1In Grenada, I am told, only twenty-two to twenty-
six hours are necessary.—H. H. S.

200 The Fermentation of Cacao

polish is secured at the same time by the long-
continued slow rotary motion. It is also
claimed that there is an advantage of resultant
weight over sun-drying by this process, and
its users more or less endorse this claim. The
machine may be briefly described as one or
two large. cylinders rotated slowly by a steam
engine which also works a powerful hot-air fan.
These cylinders have a hollow axle, with radial
perforated tubes through which the hot air is
forced in all directions from the interior to the
exterior of the slowly moving cacao. There
are also specially designed protuberances from
the core that facilitate the thorough mixing
and polishing of the mass. I have seen several
of these machines at work and they have given
satisfaction, although considered to be dis-
tinctly costly. Points that have been raised
against them are: the large amount of wood
fuel they consume, and the liability of boiler
tubes to’ burn out and require replacing within
two years. On many thoroughly developed
estates in Grenada the fuel question is becom-
ing a serious expense and difficulty, but in
less developed cacao countries fuel should be
plentiful for many years to come. It must
be noted as a very salient feature of the
subject that most estates possessing ‘‘ Gordon ”
Dryers are usually content to use them as a
‘‘stand-by” and cure a large proportion of
their crops by sun-drying.

For smaller properties the ‘Hamel Smith ”

Mr. George S. Hudson 201

Rotary Cacao Dryer is a machine that has
lately been put on the market and promises
good results. It is extremely difficult for
the planter to become conversant with the
advantages and defects of new machinery of
this kind, unless individual planters take the
risk of ordering some of these promising,
but untried inventions. As an instance, the
Gordon machines have been on sale for twenty»
years, but it is only within the past five years
that they have become appreciated in the West
Indies. The work of testing new inventions
of this kind should be taken up by the
agricultural bodies for the guidance of the
agricultural community, as it is hardly fair to
individual inventors, makers or planters, to
leave them to bear the cost of experimental
work whereby all benefit, if only by ascertain-
ing that the machine cannot be used with
advantage. ;

Vacuum Cacao Drvers.

I am strongly of opinion that the ease,
economy and certainty of drying cacao zx
vacuo will eventually cause it to supersede
all other methods on estates producing 100
bags or more annually. In West Indian
central sugar factories no other method of
boiling sugar but in vacuum pans has been
entertained for the past forty years; and
although many of these factories cannot afford
highly paid engineers, yet the difficulty of

202 The Fermentation of Cacao

obtaining an efficient vacuum (which is the
generally expressed objection to this system)
has not been found a prohibitive factor or
even ‘one entailing difficulty. It may be
imagined that this process of evaporating, or
concentrating in vacuum, is a new and untried
one, but as a matter of fact hardly any sugar
factory is complete without a vacuum dryer or
concentrating pan. I have before me a list of
the manufactures in which the vacuum pro-
cess is used, but I fear it is much too long to
inflict on my readers; it may be said to
comprise nearly all the vegetable products of
the world, and of its economy as regards fuel,
labour, time, space, supervision, and money, in
comparison with all other systems of drying
and concentrating, not a doubt can exist.

In 1908 the writer arranged for a cacao-
drying trial in vacuum in his presence at the
works of Messrs. George Scott-and Co., Ltd.,
London. Two barrels of nearly ripe ‘cacao
pods were sent to England in the cold-air
chamber of a Royal Mail steamer, and arrived
in good condition. The seeds were then
soaked in water, drained, and placed in a
vacuum dryer made by that firm. A vacuum
varying from 28 to 28% was established, and
the interior heat was regulated to 95°to 100° F.
Two trials were made, and in each the dryer
was opened after five hours, when the cacao
was found to be slightly over-dried. Consider-
ing the cacao had not undergone regular fer-

Mr. George S. Hudson 203

mentation the sample proved quite satisfactory.
The makers were of opinion that with fer-
mented cacao and a constant vacuum of 28,
drying would be efficiently performed in three
and a half to four hours, and I quite agree
with this opinion. During the time the cacao
was drying the only work entailed on the
attendant was to regulate the temperature and
see that a good vacuum was maintained. This
trial quite converted me to the advantages of
a cacao vacuum-dryer, and pointed out possi-
bilities and benefits non-existent under other
systems. Makers of vacuum dryers claim that
owing to low temperature, rapidity of drying,
and absence of hot-air currents, the essential
oils and volatile salts forming the aroma and
flavour of cacao are retained, and also the
plumpness of the seed and its attractive colour.
This claim has much to recommend it. Also,
with a given vacuum and uniform temperature
identical results could always be obtained
within a definite period, and a rule of thumb
method adopted by the untrained native
attendant whereby the difficulty of curing
successive batches of cacao to a recognized
standard of colour, dryness and appearance
would disappear. The space occupied by such
a plant is very small, consequently there would
be economy in buildings, also in fuel, in water,
in wear of machinery (as nearly all parts are
stationary), and one man could lift the dry-
ing trays out, and put a fresh set in, do all

204 The Fermentation of Cacao

the necessary work of refilling a Set of spare
trays for the next charge whilst the first
charge is being dried, close the air-tight door,
start. the exhaust pump, and regulate the
temperature. At first glance it would appear
advisable to use a rotary vacuum cylinder
in place of a stationary rectangular vacuum
chamber in order that polishing might be
effected at the same time as drying, but, taking
into consideration additional difficulties in pre-
serving a good vacuum in a rotary machine,
and the fact that four hours’ slow rotating
would not perceptibly polish the seed, one is
forced to conclude that with the beans placed
three or four deep on the trays it would be
necessary to break the vacuum after about one
and a half hours’ drying, and pass the beans
through a polisher for ten minutes to give them
the best appearance, and prevent them adhering
to one another, and then return them to the
dryer to complete curing. If cacao ‘‘washing”
were economically possible, polishing might be
saved and the drying process in vacuum carried
out straight to its end, when a very slight hand
manipulation would serve to separate adhering
seeds. With the necessity of polishing, an
average day’s work would hardly cover more
than two charges of the dryer, but during
crop pressure three charges per diem might be
put through. This point is of importance in
establishing the size of dryer necessary for an
estate, and due regard must be paid to the

Mr, George S. Hudson 205

fact that the average ‘‘boucan” attendant is very
dilatory unless under direct supervision of the
“boss.” In computing the drying area neces-
sary it is safe to assume that on most estates
two-fifths of the crop is reaped within two
months, or, say, fifty working days; therefore
a 250-bag estate would require to dry 100
bags within fifty days, a 500-bag estate would
require to dry 200 bags within fifty days, and
soon. Taking two bags a day as a minimum
day’s picking, even on a 100-bag estate (bags
of 200 Ib. dry) we should require to deal with
about 1,200 lb. wet cacao per diem, or about
three charges of 400 |b. each, at the busiest
time. Messrs. Scott's No. 1 machine would:
contain 400 lb. wet cacao each charge, with
a tray surface of 56 sq. ft, and the beans
2 in. thick.t | Such a dryer would cost about
4140° complete in England. The next size,
No. 2, can take 600 |b. per charge, and
with three charges per day would dry three

1There must surely be something wrong here, but
although we returned the MS. to Mr. Hudson to be
corrected, he still passed these measurements. It is
impossible, however, for 400 lb. wet cacao to be spread
over a space of 56 sq. ft. by 2 in. thick. H. H. S.

21 believe these figures no longer hold good, even if
they were correct at the time. The Passburg Dryers,
at any rate, cost to-day (May, 1913) as follows:
No. 9, to take about 3 cwt. wet cacao, £360; No. 12,
to take 5 cwt, £430, deld. f.o.b. Hamburg. For such
sizes this works out at about 1 lb. of fermented beans
per sq. fi. of heating surface, so that the price gives
some idea of the capacity of each size of stove —H.H.S.

206 The Fermentation of Cacao

bags of 200 lb. each, and would cost about
4210 in England. It is obvious that if we
can cope with times of pressure, the rest of the
year’s crop can be easily safeguarded. The
machines of Emil Passburg, of Berlin, are more
expensive, but it is only fair to say that their
reputation is very high. Apparently Pass-
burg’s machine, capable of taking 3 cwt. of
wet cacao in one charge, costs £300 in

Berlin without boiler or pump, while a Pass-
burg dryer to contain 13 cwt. per charge is_
quoted at £700! complete with boiler, pump,

and extra trays; one pump and condenser can,

however, be used with three or four drying
chambers for very large crops. This latter
machine should turn out six and a half bags
of 200 lb. each of dry cacao per day, and
should therefore be able to handle a crop of
800 bags per annum; its cost, therefore, in
comparison with the price of Gordon dryers,
does not seem excessive. The Passburg dryers
have apparently gained repeat orders from cacao
estates in the Cameroons and West Africa, and
they are also used for rubber drying in the
Malay States. It is quite possible that
difficulties may arise at the outset in the
manipulation of these dryers, and it is this fear
that deters planters with little or no engineering
experience from putting down their hundreds
of pounds for new machinery. I again suggest
that it is the business of the different State-

1 This ought to be about £825.—H.H. S.

Mr. George S. Hudson 207

aided agricultural departments and societies
to try preliminary experiments with these
machines, and according to results report °
favourably or unfavourably upon them. It is
more than probable that the makers would be
only too pleased to co-operate in these trials
with a view to lessening the cost. The
prospect of taking one’s cacao from the fer-
menting box at 6 a.m. and getting it dried,
polished, bagged up, and carted away by the
afternoon will appeal to most planters as a
most desirable state of things, which we may
hope some day to realize, as others are
apparently doing even now.

WasHED Cacao.

While one cannot doubt that the large cacao
buyers in Europe and the United States are
trained, keen experts at their trade, it is a
curious point to the planter that they will pay
2s. per cwt. more for “polished” or ‘“clayed”
cacao, which only improves the superficial
appearance and adds to the weight without
improving the quality in any appreciable
degree, and yet can only be induced to give
the same advance on ordinary prices for
‘“washed” cacao, which, according to general
observation, frees the beans from gums and
other extraneous matter (which should be of
no use to the manufacturer) to the extent of
from 4 per cent. to 15 per cent. in dry
weight. My own experiments place the loss

208 The Fermentation of Cacao

in weight resulting from. washing at 7 per
cent. Only on the assumption (which we
hesitate to accept) that the testa or seed skin,
with its adherent matter, is used indifferently
with the seed contents in manufacturing
chocolate or cocoa, can one justify this valua-
tion. In consequence of this anomaly, cacao
washing is only practised with the higher
grades’ of Ceylon, Central American and
Samoan cacaos.’ It does not pay the producer
of West Indian, Brazil and African cacao to
lose 7 per cent. in weight and gain 2s. per
cwt., even at the present depressed value of
cacao, and it is distinctly unfortunate for both
producer and manufacturer that such is the
‘case. We contend that if the manufacturers
see their way to pay, Say, 55s. per cwt. for
a sample of unwashed, polished “Fine Estates”
Grenada or Bahia, they should also be in a
position to offer at least an equivalent of
7 per cent. more for a good sample of
‘“washed” cacao, or, say, 58s. 6d. per cwt.,
for they get 7 per cent. more cocoa and 7 per
cent. less skin and other detrimental matter.
There is little doubt that a “washed” cacao
is a finer product than ‘‘clayed” or “ polished”
seed. Owing to the early removal of pulp, gums,
and products of fermentation from the seed
skin there is very little tendency to mildew,

1 That is to say for Criollo, 72. the thin-skinned
variety.—H. H. S.

Mr. George S. Hudson 209

which subsists principally on these unnecessary
substances.

The process of airing ‘‘washed” cacao
differs somewhat from that heretofore des-
cribed. On the morning of the day previous
to that on which fermentation is anticipated
to be complete (z.e., twenty-four hours earlier)
the cacao is removed from the fermenting box
and thoroughly washed. It is then exposed to
the sun for a few hours, and while still slightly
damp and heated is returned to a sweating box
lined with large leaves and carefully covered
until next morning, when a further fermenta-
tion will be found to have taken place. It
is then placed on the drying trays, when it
will only mildew under the most adverse con-
ditions (in which case it is again washed), and
given good sunny weather, attains a thorough
degree of dryness within four or five days.
The colour of the beans is a clear, attractive

red, and they retain their plumpness and good
“ break.”

Cuavep Cacao.

This process consists of sprinkling a very
finely powdered red earth on the seeds on or
about the second or third day of drying and
working it into the cacao by trampling with
bare feet. It imparts a characteristic dull red
uniform colour to the sample, and this appear-
ance is recognized as being distinctive of a
certain class of Trinidad and Venezuelan cacao.

14

210 The Fermentation of Cacao

Beyond possessing a deterrent effect on
mildew it cannot be said to constitute an
improvement in curing, neither does it add
materially to the weight, as the quantity of
powdered earth used rarely exceeds 1 per cent.
of the cacao weight, the value of which does
not cover the cost of the materials plus the
labour involved. Originally this plan was
practised by a few estates turning out a
_ superior high-class sample, and the higher
prices obtained were doubtless more due to
this fact than to the addition of coloured earth.
Nowadays many shippers of inferior cacao use
“clay,” and it is no longer a hall-mark of good
quality ; its use, therefore, is not recommended.’

Fret PoisuHinc, or-** DANCING.”

Cacao is generally fit for ‘ polishing” on
the morning of the third or fourth day’s drying.
If attempted at too early a stage the gloss
attained will be poor and evanescent owing
to the presence of too much moisture in -the
seed, while if delayed over long the seeds
become too brittle ‘and are liable to crush
under the process of polishing, which consists
really of rupturing the oil cells just beneath

1 Unless it is to hide outer defects of the beans; the
tendency of late has been to send less clayed cacao,
especially Venezuelan, to market. One of the leading
American makers seems to be especially averse to pay
for the extra weight, even if it only amounts to 1 perf
cent., as Mr. Hudson claims.—H. H. S.

Mr. George S. Hudson 211

the surface. of the seed skin by applying
considerable friction to the mass of cacao.
To obviate crushing and to allow the seeds
to glide easily over each other they are slightly
damped by sprinkling water on them just
previous to polishing. One pint of water per
hundredweight should be ample. The opera-
tion of dancing is sometimes, performed on the
flat surface of drying trays, or on a floor in the
drying house, when in addition to the ‘dancers ”
it is necessary to have other attendants to
continuously sweep back the cacao under the
feet of the polishers. A more economical way
is to utilize some receptacle with curved, bowl-
like sides so that the cacao automatically falls
back under the ‘“dancers’” feet; for this
purpose the old-fashioned Muscovado sugar
boiling iron ‘‘tayche” is remarkably well
suited and is much in favour. The labour
involved before the seeds attain a good
‘‘sloss” is rather tiring, as each batch of
cacao of say 2 cwt. will take two men half
an hour or longer to polish. On many estates
it is performed. by “task” work at the rate
of 3d. to 4d. per bag of 180 Ib. (dry weight),
and then, of course, the work proceeds, more
expeditiously, but there is every temptation to
add too much water to quickly attain a fictitious
polish which is not retained permanently. The
gloss should proceed from the ruptured cells
permeating the seed skin, and giving it a
darker, shiny, and much improved appearance

212 The Fermentation of Cacao

from which signs of mildew have disappeared,
except in very badly mildewed cacao, where
evidences of it may still be seen persisting in
the deeper wrinkles of the seed. When sun-
drying is relied on, it is necessary that polish-
ing should not be continued much after mid-
day, in order that the seed may receive
sufficient sun heat when replaced on the
drying floor to preserve their gloss and obviate
any further chance of mildew during the night,
which would entail another “dancing” next
day. It is a tedious, annoying, wasteful and
unprogressive manner of effecting work which
can be as efficiently done in ten minutes by a
machine at a saving in expense, an improve-
ment in the product, economy of supervision,
and the liberation of many workers for more
useful estate work.

MacuHINE POLISHERS.

Within the past three years two machines
for polishing cacao have been placed on the
market, both of which have proved their capa-
bility of polishing from two to two and a half’
bags (of 200 lb. dry weight) of cacao in ten
minutes ; there are also smaller hand machines
of the same types, the utility of which is as yet
doubtful. The two successful machines are
both worked by small oil engines, or any other
available power.

The Matins-Smith Polisher consists of a
wooden cylinder to which, by means of a

*

Mr. George S. Hudson arg

countershaft, two separate actions are com-
municated—viz., a slow revolving action fifteen
times a minute to the cylinder, in the interior
of which six wooden sticks or spindles are
geared to revolve at the rate of 360 times a
minute. The writer purchased one of these
machines from the makers, Messrs. J. Gordon
and Son, London, for £40, but owing to un-
satisfactory workmanship and materials great
difficulty was at first experienced with this
machine, which is unfortunate, for Mr. Malins-
Smith’s invention is a very simple and good
one. However, by employing a more powerful
engine’ and running the machine constantly,
either empty or with small loads of cacao, the
working has gradually become easier and is now
satisfactory. A single machine at ‘“ Diamond ”
Estate, Grenada, handles easily a crop of
1,100 bags. The choice of a good oil engine
of suitable horse-power is half the battle with
these machines, and the advice of the inventor
(Mr. W. M. Malins-Smith, Grenada) should be
taken on this point. Contrary to what one
might expect with rapidly moving parts, there
is less crushing of seed with machine polishers
than by the old-fashioned foot method.

The Barnard machine, invented by Mr.
George Barnard, of St. Lace, consists of a
slowly. revolving iron cylinder in the lower half

1 Insufficient horse-power was the trouble throughout,
I believe—H. H.S

214 The Fermentation of Cacao

of which four rubber-clad metal feet work
quickly to and fro on eccentrics. I hear the
highest reports of its efficiency and believe the
price of the 24 bag ‘‘ Barnard” machine, made
by. Messrs. Gillespie Bros., London, to be some-
what less than that of the ‘“‘ Malins-Smith.”
We thus have two machines which, when
properly put on the market, are quite capable
of polishing ‘about 500 Ib. cacao (dry weight)
in ten minutes, at an expenditure of about one
halfpenny for gasolene or kerosene. Allowing
time for filling and emptying the machines,
starting the engine, &c., from. twenty minutes
to half an hour should be occupied with each
charge, and one man only is required in
attendance. The principal advantage, how-
ever, lies in the fact that by 8 a.m. each
“morning all polishing is finished, and the cacao
is again in the sun, minimizing chances of
a second attack of mildew and _ practically
guaranteeing the retention of a fine gloss. on
the seeds and a consequently better sample
and higher price. By their use the ‘‘ dancing”
gang ‘would be practically abolished. The
‘whole cost of such an installation may be
taken (including the best type of oil engine) at
4100, equivalent, at 6 per cent. interest and,
6 per cent. depreciation, to an annual charge
of £12 a year on initial cost. Taking this
‘into consideration, plus the cost of motive
power and lubricating oil, &c,, &c., we have
no hesitation in affirming that estates pro-

Mr. George S. Hudson 215

ducing 200 bags and over will find it economical
and convenient to polish by machinery. i

BaGGING.

It is unfortunate that the term “bags of
cacao” is used so largely in cacao statistics and
estate returns, for it is susceptible of the most
elastic interpretation. Thus a St. Thomé bag
weighs 60 kilos, or 120 Ib., and the Trinidad
and Grenada bag is. generally conceded to be
180 lb., while many cacao bags weigh as much
as 240 lb. It would certainly be better to talk of
cwts. or kilos, than of bags of cacao, unless
some definite standard of weight is implied by
that term. Taking into careful consideration :
(1) The cost of the bag; (2) filling, sewing
and marking ; (3) transport to shipping place ;
(4) cost of warehousing and shipping; (5)
freight rates; (6) dock charges; (7) deduc-
tions for tare and tret on London and Havre
basis ; and (8) public sale charges, it will be
found that the bigger bag, not exceeding 229 lb.
gross, favours economy from beginning to
end. The empty bag should weigh slightly
under 3 lb.," and the London account sale net
weight, allowing 2 Ib. for ‘‘ tret,” should work
out at 2 cwt. per bag.

1 This is too light for a bag capable of holding over
175 lb., which should weigh 34 to 3# Ib., otherwise it
would be too thin to stand the knocking about the bags
get en voyage and might burst, causing the beans to
leak out.—H. H. S.

216 The Fermentation of Cacao

By-products.
VINEGAR.

‘A careful measurement of the liquor oozing
from cacao fermenting boxes gives 4 imperial
gallons, or about 20 litres, of juice per bag of
200 Ib. dry. Thus for every 100 bags pro-
duced there would be 400 imperial gallons of
juice to deal with in the first instance. This
quantity would be reduced by evaporation,
fermentation, and filtering over at least two
months’ treatment, so that it probably would
not yield more than half its original measure,
or 200 imperial gallons of vinegar. Assuming
that a fair vinegar was turned out, and taking
into consideration the quality and price of
the English malt and French wine vinegar
now generally exported to the Colonies, the
producer of cacao vinegar might reasonably
expect to receive 2s. to 2s. 6d. per gallon
wholesale. This would represent a gross
return of, say,’ £20 per 100 bags cacao at 2s.,
or 425 at 2s. 6d. per gallon. Very occasionally
one meets with cacao vinegar that appeals to
the palate as the very perfection of vinegar ;
although it is not deficient in strength (as

‘If, therefore, taking one centre alone, Trinidad
exported 300,000 bags of cacao in a year, as it could
and should do, the vinegar forthcoming should, on
the above basis, be worth 3,000 x £20 = £60, 000
at least, and perhaps £75,000. This is not at all a
bad sum for a by- product at present running to waste,
and by ee so proving an expense and a nuisance.
—H. H:

Mr. George S. Hudson BAZ

Dr. Nicholls’ analysis shows) its great points
are exquisite mellowness and freedom from all
“bite.” The secret of this chance production
of quality is probably the correct ferment and
age—and by age it is not sought to imply any
length of time exceeding twelve months, but
probably less than that period—further, the im-
provement in quality does not date.from filter-
ing and bottling, but rather occurs in ‘‘ bulk,”
when the vinegar still retains its fungoid accre-
tion floating on its surface, vulgarly known as
“the mother.” Householders all over the
world would gladly pay 1s. per litre for this
superior quality of vinegar, and the supply
could not meet the demand. On ‘the other
hand, there is no natural demand whatever for
the cloudy, half fermented, unpleasant looking
cacao vinegar one frequently finds exposed for
sale at 6d. to 8d. per bottle; unless the out-
turn of a superior article is aimed at it would
be better not to attempt vinegar-making. A
uniform-sized, clear glass bottle, with attractive
label and capsule, should be part of the outfit
for a retailer. There is nothing that so effect-
ually hinders the sale and success of local

roducts as an appearance of being carelessly
and hurriedly prepared and cheaply ‘‘ put up ”
for sale ; the natural appearance of cacao vine-
gar being of a clear rose colour, its attractive
appearance is a considerable asset in its favour
in comparison with other vinegars.

I cannot pretend in this essay to any satis-

218 The Fermentation of Cacao

factory knowledge of vinegar manufacture, but
the following points may prove worthy of
consideration of prospective manufacturers.
Having secured the most favourable ferment,
very much depends on the fermenting: tanks
used; this is:where the,amateur manufacturer
invariably gets wrecked. Wooden receptacles
are entirely unsuited; under the influence of
cacao vinegar the best casks become rotten
and pierced by worm-holes within a few weeks.
Quite as unsuitable are glass demijohns or
earthenware jars with contracted necks. . After
standing a few weeks a flat fungoid growth
will be seen floating on the vinegar surface,
and this gradually increases in size. This
fungus in narrow-necked receptacles prevents
the clear liquid being poured off, and in fact
one ‘cannot produce clear, bright vinegar
by pouring. The vinegar when’ thoroughly
mature and clear, and ready for bottling or
sale, should be siphoned off,'as taps would.
always prove troublesome. Possibly the more
cloudy remainders might be efficiently dealt
with by one of the filters in use in kindred
trades, such as Macqueen’s ‘Filtre Rapide,”
and other devices used in bottling wines and
spirits, such as “finings” of white of egg and
isinglass. It is probable that a portion of the
fungoid growth from a superior mature sample
of vinegar would be the best method of infect-
ing a new batch of juice with the same fer-
ment. There is, undoubtedly, much room for

Mr. George S. Hudson 219

useful experimenting in the direction of vinegar-
making in the Tropics. It is probable that a
series of four tanks built of concrete, and lined
with glazed earthenware or slate, fitted with
acid-resisting joints, would fulfil an ordinary
estate’s requirements. They should have tight-
fitting covers to exclude dirt, dust and vermin.

Cacao ALCOHOL. —

The fermenting juice of cacao fulfils. all the
conditions necessary to the making of a potable
spirit by distillation, and even of the making
of wine. Unless, however, a superior and
high-priced liquor were produced (and hitherto
all cacao literature is silent on this point) it is
probable that its production would not be
profitable.’ It would be most interesting to
ascertain what sort of a new drink cacao juice is
capable of producing, and it is a matter that a
Tropical Agricultural Department with a little
initiative might well follow up, containing as
it does the prospect of creating a market for
several hundred thousands of gallons of liquor

1In Parad, I understand, many of the planters pay
more attention to producing an intoxicating drink from
the green cacao than to the commercial beans them-
selves. { am told that the characteristic flattened
shape of Pard cacao is due to the pressure it undergoes
in the cylinders made of Indian woven matting, which
by means of weights, or hand-pulling at the end (as
when making “farine’” or cassava, which has to be
freed. of its poisonous juices), squeezes out almost the
last drop of liquid in the mass.—H. H. S

220 The Fermentation of Cacao

now running to waste. A distiller could pro-
bably purchase all the cacao juice produced in
his locality for 3d. per gallon, or about the
price of Central Sugar Factory molasses used
for inferior qualities of rum, but a gallon of
cacao juice would by no means produce the
same amount of alcohol as a gallon of molasses ;
it might, however, yield a spirit of superior
quality, and probably would do so.

Cacao JELLY.

An edible jelly is occasionally made from
cacao juice to which an equal bulk of sugar
is added. Its manufacture is almost identical
with the well-known method of making guava
jelly, but that made from cacao juice cannot
compete with the characteristic, delicious and
luscious flavour of well-made jelly from guavas.
Beyond a sub-acidity it is almost characterless
in taste, so might, on that account, form a basis
for added flavourings.

221

CHAPTER VII.

Forming with Chapter VI, by Mr. George
S. Hudson, the Joint Prize Essay men-
tioned in the Preface.

By Dr. LUCIUS NICHOLLS.

FERMENTATION is the reduction of sub-
stances of high molecular composition to those
of a less complex nature by the agency of
micro-organisms, and this has a wide range
in commercial preparations, where both the
physical.and chemical changes are of value,
thus: the making of bread, the preparation
of all alcoholic beverages, cheeses, tobaccos,
vinegars, and even the tanning of leather are
dependent upon it. In all these trades certain
definite organisms must be employed to bring
about the required result, and these are usually
present naturally ; but this is not always the
case. Science in this, as in most other sub-
jects, has in recent years thrown light upon
much that was perplexing, and its explanations
of the changes which take place in fermenting
matter have been of much assistance to some
of the interested trades. It was the genius
of Pasteur which first explained the so-called

222 The Fermentation of Cacao

‘“ diseases’’ of wines, in which, instead of a
proper fermentation taking place, souring
occurred. This he showed to be due to the
presence of undesirable organisms; soon after
this, methods were discovered by which the
organisms that brought about the required
changes could be separated from the more
adventitious ones. .This was a great stride,
but it has not yet been my utilized. or even
appreciated.

The ‘sweating,’ as the fermentation of
cacao is called, is brought about by some of
the many varieties of yeasts, and to a greater
or less extent by other organisms, acting upon
the saccharine pulp which surrounds the seed. -

If-a minute fragment of baker's yeast is
shaken up. in a little water, and a drop of the
resulting emulsion is placed under the micro-
scope, it will be seen to consist of many
thousands of round or oyal cells, each of which
is an independent organism: which -has the
power of growth and reproduction. The
latter is brought about -by what is known as
“budding” : a small protuberance appears on
the surface of the cell and continues to increase
in size until it is as big or nearly as big as the
cell from which it springs ; it then splits off,
and thus two cells are formed, each of which
again starts budding. In very actively growing
yeast this form of reproduction takes place
about once every half-hour and thus theoreti-
cally by geometrical. progression one cell will*

Dr. Lucius Nicholls. 223)

give rise.to a million and more in ten and
a half hours. . In double this: time there will
be produced over a million millions. of cells.
From this it is easy to appreciate the great
and rapid changes which take place in ferment-
ing matter, for each cell has the. power of
secreting a minute amount. of a substance

Dr. Lucius NICHOLLS IN GYMKHANA COSTUME.

known as a ferment, and it is this which brings
about the changes; thus the ferment pro-
duced by yeast, called zymase, has the power
of transforming sugar into alcohol with the
liberation of carbonic acid gas and energy—
the latter appearing partly as heat, It is this
energy which is required by the yeast plant to

224 The Fermentation of Cacao

carry on its vital processes; the formation of
alcohol as it accumulates becomes detrimental
to the cell.

Again, if a small fragment is taken from
the pulp in a mass of sweating cacao, smeared
upon a microscopical glass slide, stained and
examined under the microscope, a _ large
number of yeast cells are seen in their various
stages of growth and budding (fig. 1, 4); besides
these, a number of rod-shaped bodies, minute

SMEAR FROM CACAO SHOWING INVOLUTING YEASTS.

Fic. 1.—A, yeast cells, among which are other organisms ;
B, group of acetic acid producing bacilli.

dots, or elongated organisms are also noticed
(fig. 1, 3). These vary in number according to
the stage of sweating ; in the early stages they
are usually few in number, in the later stages
there are many of them. If we compare this
yeast with baker's it will be found that they
differ from one another in shape, size, and

general appearance.

Dr. Lucius Nicholls 225

There are a number of varieties of yeasts,
and many can be found in sweating cacao
taken from different situations. But, as found
in association with cacao, since they are usually
of a fairly definite type, an attempt has been
made to regard them, irrespective of minor
differences, as one species, and to apply the
name Saccharomyces theobrome to these.

The isolation and cultivation of these yeasts
and other organisms will be described later ;
it is intended to show first of all how these
organisms naturally get into the husked cacao.

If the interior of a sweating-box is scraped
and some of the scraping is examined under
the microscope, there will be seen to be pre-
sent a large number of yeasts and other micro-
organisms; from this it is obvious that as soon
as fresh cacao is mixed up in these boxes, these
organisms will immediately start to multiply
and bring about their concomitant changes in
the suitable pabulum supplied. This is not
the only way in which ‘organisms arrive in,
and distribute themselves through the cacao.
Obviously, there are few, if any, present in
new boxes, or most of them will have died
out if the boxes are not used for a long time.
In these cases there is often difficulty in
getting the sweating to start. When it finally
commences the organisms have been brought
by’ a variety of ways, some are air-borne,
others are present in the dirt on the hands of
the workers, others again are carried to the

15

226 The Fermentation of Cacao

beans by the agency of flies. In the present
system employed | believe this last is of the
greatest importance ; it is not, however, with-
out its disadvantages, as will be shown later.
In many places this carriage of yeasts to cacao
by flies is the most unvarying factor.

In order that a rapid and effective fermenta-
tion may take place, it is necessary that a fair
number of organisms are early and evenly
introduced ; for this the condition of the
atmosphere is far too variable, because the
number of air-borne organisms depend upon
the wind, the degree of humidity, and the
amount of rainfall.

Around cacao boxes in the West Indies
will always be seen innumerable small flies,
and if the sweating cacao is carefully examined
numbers of small maggots, the larvze of these
flies, will be found. So rapidly does this fly
develop that the third day after the deposit
of the eggs the maggots crawl to some dry
surface on the boxes or their lids, and there
their integuments harden into a puparium, and
ina few days the flies emerge; a week is the
average length of time occupied by the entire
development from egg to fly.

This little fly is depicted in fig. 2, It is
named Drosophila melanogaster. Fig. 2, A, re-
presents the fly greatly enlarged, 2 represent-
ing the actual size, about a twelfth of an inch
in “length. The males can be distinguished
from the females by the lower segments of

Dr. Lucius Nicholls 227

Fic. 2.—A, cacao or vegetable fly (Drosophila melanogaster),
x 25; B,actual size ; C, egg of fly ; D, egg shedding case; £,
first stage of development; /, fully developed larva or maggot ;
G, pupal case.

228 The Fermentation of Cacao

the abdomen being black and the antenne
more plumose.

The colour of the fly is a dusky brownish
yellow, and the eyes a bright red to reflected
light. The venation of the wings is simple,
consisting of five longitudinal and two trans-
verse veins, the latter cross between the second
and third and the fourth and fifth longitudinals.
The eggs are just visible to the naked eye ;
they possess two curious prolongations, which
are attached to an egg case, and this is
easily removable (fig. 2, Cand J). The larve
are amphipneustic (fig. 2, 7).

The two following experiments show the
action of these flies in conveying organisms
to cacao :—

(1) Four pods were taken, and two small
areas at each end of them were sterilized and
a small hole was drilled by a red hot iron.
Into these holes sterile glass rods of an eighth
of an inch bore were driven and moved freely
about, so as to leave a small unoccupied space
opposite their entrance on the inside of the
pods. In two cases the ends of the rods were
protected against the entrance of the flies by
tying two or three fibres of thin cotton, over
them.

The four pods were now placed in a cage
with a large number of these flies, which had
been obtained from a number of places. On
the next day they were seen crawling into the
two unprotected tubes and thus into the pods.

Dr. Lucius Nicholls 229

The four pods were opened in six days, the
two to which the flies had access had under-
gone fermentation, the other two were much
ae same as freshly picked pods.

(2) The second series of experiments con-
sisted in using fine netting through which the
flies could not crawl. Small new wooden
boxes were filled with beans and the netting
placed over them. In some of these a few
meshes of the netting were so enlarged that
these flies could just crawl through, whilst
others were thoroughly protected from the
flies, but to all intents and purposes not more
protected from the air than the former.

The results were a little variable, as regards
actual time and degree of sweating, but in all
experiments better and quicker fermentation
took place in those which were not protected
from the fly.

Yeasts and other organisms. can always be
isolated by cultural methods from this little fly.

From these experiments and observations |
conclude that this little fly is of value in that
it is always present, that it conveys the causal
organisms of fermentation to cacao, and its
larvee in crawling through and through the
fermenting mass distribute the organisms
evenly.

These flies are seen in association with all
decaying vegetables and fruits, such as plums,
bananas, and bread fruits, and from these,
yeasts and other organisms can be cultured.

230 The Fermentation of Cacao

Chemistry of Cacao.

I shall confine myself principally to that
chemistry which is concerned with the fermen-
tation of cacao.

Many analyses of wet cacao have been made
by Harrison, Bamber, Silva, and others, and
of cured cacao by Zipperer, Muter, and
Wanklyn; the most noticeable point of their
tables is the extreme variations. Thus cacao
butter varies from below 4o per cent. to above
.50 per cent., and all the other constituents
vary to much the same extent. The causes
of this are various, depending upon the variety
to be treated, the locality in which it is
grown, its cultivation, the nature of the season
(whether it has been wet or dry), the amount
of fermentation that has taken place, and the
degree of moisture present.

Some of these factors are irremediable even
if it is desirable to produce a uniform cacao for
the markets.

Fermentation takes place to its greatest
extent in relation to the saccharine pulp which
is adherent to and surrounds the testa of the
seeds, I have analysed a number of samples
of this obtained by straining fresh beans
through muslin ; they varied to a considerable
degree in composition.

I have, therefore, given three columns: the
first is the minimum, ‘the next is the maximum,
and the third the round figures which for
practical purposes can be taken as_ the
averages :—

Dr. Lucius Nicholls 231

Minimum Maximum Average

Percentages

Water ... ‘ 79°73 88°5 so—9o
Albuminoids, astringents, &e. 0°56 0°72 0'5—0'7
Glucose es ean in 8°34 13°12 8—13
Sucrose se ais ve 0°40 0°95 0'4—I
Starch . Trace
Non- volatile acids (reckoned

as tartaric) . si sis 0°25 0°42 «0'2—0°4
Iron oxide... 0°03 0°03 0°03
Salts (potash, soda, “Calcium

and magnesium)... se 0°40 0°45 0'4—0'45
Volatile acids ... ae bas Nil Nil Nil
Alcohol... ane ue Sa a rf mr

Harrison gives a table in which the com-
positions of sweatings are stated to contain
acetic acid and alcohol. This shows that his
samples had undergone slight fermentation, for
these bodies are absent from the fresh fruits.

Now the amount of acetic acid and alcohol
present depends entirely upon the amount ot
fermentation which the sweatings have under-
gone; thus, if the sample unpreserved is ex-
amined one day and again the next, a great
difference in the quantity of these will be
found. The sugar disappears and gives rise
to acetic acid and alcohol, and the ecneunt of
these depends upon the varieties of organisms
present. The amount of acetic acid may be
4 per cent. or more.

The sweating of cacao is in fact the fermen-
tation of the sugars of the saccharine pulp.
The organisms acting on this, proceed to con-
vert the glucose into alcohol and acetic acid ;
this takes place with a rise of temperature,

232 The Fermentation of Cacao

which falls when most of the sugar is converted
into these two bodies.

This produces important changes in the
testa and kernels of the seeds; some of these
are obvious, and others are shown by careful
examination and analysis. The first question
to decide is exactly how these changes take
place, and in what. way substances pass the
exterior and the interior of the seed,

If fresh beans covered by their pulp, and
other beans in various stages of fermentation,
are placed in different solutions of salts or
other chemicals, removed at various times,
washed well in distilled water, and their kernels
carefully extracted and analysed, these chemi-
cals will be found to be present; the amount
that has reached the kernels depends on the
degree of fermentation that the beans have
undergone ; fermented beans have a far greater
proportion of these, ze., alcohol and acetic
acid, in their interiors than unfermented beans.

From this it is shown that the fresh sac-
charine pulp and testas allow but limited pene.
tration, whereas the testas of fermented beans
have become good diffusion membranes,
allowing matter in solution to pass freely to
and from the kernels. It was at one time
thought that whatever passed into or out of
the bean did so by the hilum; this may occur
to some extent, but that the whole testa acts
as a diffusion membrane is shown by the
following experiment: Beans were soaked for

Dr. Lucius Nicholls 233

a few days in a solution of potassium ferro-
cyanide, they were then washed and cut in half,
the cut surface was carefully scraped, and a
minute drop of ferric chloride was placed in
the centre; as it spread it formed prussian
blue with the potassium ferrocyanide which
had penetrated the bean. The prussian blue
is very deep through the testa and that, surface
of the kernel which is in contact with it. The
irregular arrangement of the two convoluted
halves of the bean allows substances that have
penetrated to distribute themselves fairly
thoroughly throughout the kernel. It, how-
ever, takes some time for matter to penetrate
entirely throughout the seed. Thus in fig. 3
spot 4 is reached several days before spot B.

Fic. 3.—Section of cacao seed showing the convolution ot
its cotyledons.

Now in the majority of cases yeasts and
other organisms are absent from the interior of
the beans, but zymase, the ferment secreted by
yeast, can be demonstrated in the interior of
the seed; in this situation it will carry on its
usual action, and bring about changes such

234 The Fermentation of Cacao

as the reduction of sugar. It must be re-
membered that many germinating seeds possess
enzymes, whose actions are to reduce sub-
stances to a more assimilable condition for the
nourishment of the young plant. The action
of these can probably be excluded in ferment-
ing cacao, and the enzymes present in the
interior of the beans have diffused in from the
exterior fermenting matter.

It is the penetration of exterior enzymes
and the general diffusion of the products of
fermentation which bring about the changes
in the interior of the bean. Now there are
water, sugars, salts, alcohol, acetic acid, tartaric
acid, enzymes, carbon dioxide and other diffusi-
ble and soluble substances, passing in and out
of the skin of the bean, which has become a
diffusion membrane under fermentation.

From this, some of the changes which occur
are obvious and can at once be demonstrated by
analysis, other changes are brought about by
the temperature reached by the fermenting mass.

Physical Changes which are brought about in
the Beans by Fermentation.

If beans which have been fermented and
dried are compared with uncured beans many
differences are apparent: the former appear
more rounded and plumped up and of a dark
brown colour; this is due to the formation
within the kernel of carbonic acid and volatile
substances such as alcohol, which tend to
disintegrate the various portions of the bean

Dr. Lucius Nicholls 235

and thus plump it up. The latter are of an
uneven light colour and appear shrunken:
upon breaking them it is found that the bean
is tough and the fracture is delayed, its interior
colour is a harsh purple and has not suffused
to the testa, which is very adherent to the
kernel and has little masses of unremoved
saccharine pulp attached to it. In the sweated
seed the fracture is easy and sharp, showing
it to be of a very brittle nature, the interior
colour is a rich chocolate, the kernel is not
adherent to and is easily removed from the
testa.

The Losses and Gains in the Constituents of Cacao
when undergoing Fermentation.

It is practically impossible to estimate the
exact losses and relative gains in cacao beans
undergoing fermentation; the reason being
that there is no unvarying factor present, from
which we are able to get the proportions.

It has been usual to consider the fats in
cacao as remaining unaltered in amount during
fermentation and drying, but although they
are the least affected of the constituents there
is undoubtedly a slight loss. The melting

point of oleum theobrome is from 28° to
32° C. (82°—g0° F.) ahd the higher of
these temperatures is always reached not only
in the fermentation, but also during the drying
and dancing processes; the result is that the
fats ooze through the testa and thus to the
trays and the sides of the dancing vessels.

236 The Fermentation of Cacao

Oleum theobrome is, however, the only
constituent which is entirely absent from the
sweatings of the second and third days of
fermentation ; it must therefore, for purposes of
analysis, be considered a fixed quantity, and
the proportions of the sugars, theobromine,
cacao red, &c., to the fats be gauged in the
fermented and unfermented beans of the same
sample, for this is the only way of deciding the
approximate amount lost from the kernel of the
bean during fermentation.

Glucose.--The percentage of this in the
uncured beans may be said to vary inversely
with the percentage of sucrose (cane sugar)
present. The two together form 1 to 1% per
cent. of the cacao. In the well-fermented
dried beans there is only a trace of glucose
present. In other samples it may be found
that there has been only a slight loss, or per-
haps even a gain; the reason of this is that
the sucroses and starches: have been con-
verted into this sugar, which in its turn has
not undergone further fermentation, or else
some of the sugar in the saccharine pulp which
has a high percentage has diffused in.

Sucrose.—This is always absent from the
cured cacao, having been inverted to glucose
and thus to alcohol and acetic acid.

Starch.—This is from so per cent. to 12
per cent. of the cured cacao. There has been
a slight loss; this is dependent on the degree
of fermentation,

Dr. Lucius Nicholls 237

Theobromine and Theine.—This was esti-
mated by Kunge’s method; in three samples
two showed a slight loss relative to the fats
and the third showed practically no loss.

Cacao Red. — Determined by Zipperer’s
method : the possible errors in the technique
for estimating these complex products render
it impossible to gauge very small losses. The
fact that cacao red can be found in the later
sweatings shows that there is some loss,

Albumen, Fibrin, Gluten, &c., show a slight
loss.

Bitter Principle.—The nature of this and its
analysis have not yet been determined.

If cacao beans are broken up, an equal
quantity of water added and the mass filtered,
the bitterness will be found to have come away
with the small quantity of water ; if the filtrate
is now boiled with a very dilute mineral acid
it ceases to be bitter.

Undoubtedly bitterness is lessened by the
fermentation of the beans. But as the bitter-
ness can be easily got rid of by the manu-
facturer, it does not appear desirable to carry
fermentation to the stage of putrefaction when
this bitterness disappears.

Salts-—These remain practically constant.
A small amount probably diffuses out from the
kernel.

Acetic Acid, Alcohol and Acetic Ether.—
These diffuse into the bean from the exterior,
also small amounts are formed in the kernel.

238 The Fermentation of Cacao

These bodies tend to disappear if the beans
are kept for a length of time. Perhaps a few
others are formed, in which case the beans (all
else being equal) would improve with keeping.

Summary of the Changes which take place.

(1) The testa is rendered ‘more brittle and
acts as a diffusion membrane. Cacao red and
other constituents diffuse into it.

(2) ,The kernels assume a diffuse chocolate
colour, are plumped up and become less ad-
herent to the testa; this is the action of the
volatile substances and the carbonic acid gas,

(3) The sugar and, to some extent, the starch
are converted to lower products, such as alcohol,
acetic acid and carbonic acid gas.

(4) The fats are lost’to a very slight extent.

(5) Theobromine and cacao red are also very
slighnly lost.

(6) Some of the bitter principle is reduced or
diffuses out of the bean.

(7) Acetic acid and alcohol become present
in the kernel.

The Isolation and Cultivation of the Organisms
which Ferment Cacao.

The principle of the cultivation of organisms
is to provide them with a medium which con-
tains only food material and substances which
are favourable to them.

The medium must vary with different classes
of organisms: thus yeasts will flourish upon
saccharine media in which there is an absence

Dr. Lucius Nicholls 239

of proteids; other organisms, such as those
which putrefy meat, will not flourish upon this,
but require the presence of peptone or some
other proteid.

Many media can be prepared upon which
the organisms that ferment cacao will flourish.

I have found the medium with the following
composition, the most useful for practical
purposes :—

Magnesium sulphate a0 o’5 grm.
Calcium sulphate... agai 0'5 ss
Calcium phosphate ... sets O75) ss
Potassium nitrate ... vile O75 4
Sodium chloride... Ls O5 (Cy,
Iron perchloride’... aes O'05 4,
Potato (finely cut up) _ 2 OZ.
Glucose ni fics i 50 grm.
Agar ... wii sis sip T5455
Distilled wate sa cee 1,000 C.C.

This forms a moist, solid medium upon
.which yeasts, bacteria and moulds flourish
luxuriantly.

It is boiled, filtered, poured off into test
tubes, and sterilized in an autoclave; some of
the tubes are sloped (vide fig. 4, p. 240), others
are kept for plate cultures.

I use another medium which contains starch,
alcohol and only a small quantity of sugar, for
the purpose of isolating acetic acid bacilli and
cocci.

The method now pursued is to obtain Petri
plate cultures from sweating cacao. A plati-
num loop is sterilized and pushed into the

240 The Fermentation of Cacao

deeper layers of the beans in a sweating-box ;

when it is withdrawn, the small amount of
matter adherent to the loop is shaken up ina
saline solution, and various dilutions of this are
made. These dilutions are now either shaken
up in the molten agar media at 45° C. and

F1G, 4.—Sloped agar tube showing yeast growing on
the sloped surface.

poured on to Petri’s plates, where they are
set into solid media, or else the dilutions are
poured over the surface of media which have
already set on these plates. These plates
are now incubated at between 37° and 4o°C.,

Dr, Lucius Nicholls 241

and in tweive hours small white colonies will
be seen appearing. What has happened is
that in the dilutions the organisms were
widely separated, and thus, when mixed with
or passed over the solid media, they fell in
different places and thus each organism grew
into an isolated colony.

These colonies are each touched with the:
point of a platinum needle, and the point
smeared upon the sloped surface of medium in
a test-tube (vede fig..4); this is incubated, and
the next day a luxuriant growth of a separated
organism is present in the tube. Thus there
has been isolated an organism in pure culture.
Now its action can be tested upon various
substances, such as sugar or the saccharine
pulp of cacao.

By these methods the organisms which are
present in the sweating-boxes on the different
days can be isolated and their actions tested.
By the number of colonies of yeasts and other
bacteria, the proportions of these to one
another can be gauged on the different
days.

At the same time that cultures are taken
from the sweating-boxes, smears are made on
microscopical slides from the adherent pulp;
these are stained with carbol thionine blue;
or some other aniline dye, also by Gram’s
method, and examined under: the microscope,
using magnification power of 1,000.

By the nature of the organisms present the

16

242 The Fermentation of Cacao

fermentation of cacao might be divided into
three stages :

(1) The yeast stage, in which the vast
majority of the organisms present are “ wild”
yeasts.

Fig. 5 is a smear showing the rapidly
growing cells of this stage. -

(2) The acetic acid producing bacteria
stage.

Fic. 5.-—A, baker's yeast; Band D, two varieties of yeast

found in cacao; C, an actively growing cacao yeast.

This sets ,in as the fermentation reaches its
height. Fig. 1,2 shows these organisms be-
coming numerous and the yeast cells lessening.

Fig. 6 shows three of these isolated by
cultural methods ; two are bacilli and one isa
micrococcus. :

(3) The commencing of a putrefactive stage ;
this occurs at the end of fermentation, when
the yeast cells are disappearing, and a large
number and variety of bacteria and moulds:
appear.

Dr. Lucius Nicholls 243

‘In this stage it is not always easy to isolate
the yeast cells by cultures, as they themselves
are being attacked and broken up by smaller
organisms. °

A colony of yeast growing upon a solid
medium is fairly easily distinguished from a
colony of acetic-acid-producing or other
bacterium.

Colonies, on a solid medium, of the wild
yeasts, including Saccharomyces theobrome,

Fic. 6.—Three forms of acetic acid producing bacteria.

consist of a central, heaped-up, granular portion
and, spreading away from this, a lighter,
thinner, radiating zone; after a few days the
colonies lose the outer zone and assume a
white, opaque, granular appearance. These
are easily distinguished from most colonies
of other organisms, which usually possess a
shiny smooth-looking appearance.

Sometimes it is found that the bean does not
undergo its proper and usual fermentation ;

244 The Fermentation of Cacao

especially is this the case when using new
boxes. If on these occasions a bacteriological
examination is made, it will always be found
that there is a preponderance of other organ-
isms and a scarcity of yeasts,

Again, occasionally the cacao nearest the
sides of the boxes blackens; an examination
of this shows a large number of fungi and
bacteria which have invaded the material, and
consequently the yeast cells are degenerating
and being broken up. ;

A large amount of unsweated cacao is
placed upon the market; most of this comes from
peasants and petty proprietors. It is bought
by the merchants from these people in a moist,
rather dirty condition with much of the
saccharine pulp still adherent to it. In most
cases it will not sweat. when subjected to the
usual procedures.

A proper and thorough fermentation can
always be started by employing cultures of
yeasts; sweating will proceed as well in new
boxes as in old, and even a properly cured
sample can be obtained from peasant’s cacao,
provided too much of the saccharine pulp has
not been removed.

It can be shown by carefully excluding other
organisms that ‘‘ wild” yeasts, and these only,
are all the organisms which are required for
the production of a proper fermentation in
cacao.

Instead of trusting to chance to bring the

Dr, Lucius Nicholls 245

right yeasts to his boxes, it is urged that the
planter should employ cultures for the starting
and prolonging of fermentation. If cultures
of yeasts are well. mixed up with fresh beans,
sweating starts sooner and continues longer,
and a better sample is obtained than by the
ordinary process. The reason is that the
yeast cells obtain the first chance and then
extraneous .organisms cannot so easily get the
upper hand.

If it is-desirable to prolong fermentation
it can be done in this manner: a solution
containing 5 per cent. glucose and g5 per cent.
each of calcium phosphate, calcium sulphate,
magnesium sulphate, potassium nitrate, and
sodium chloride is poured over the beans on
about the fourth day, when the temperature
begins to fall; the temperature will now rise
and fermentation will be continued for about
two days longer than usual. The cost of this
solution would be the price of about 2 oz. of
beet sugar, for the salts of this strength cost
practically nothing, and the two resulting pints
of this solution would be nearly sufficient for
the contents of two large sweating boxes.

If samples prepared by cultures of yeasts are
examined, the perfect break, the through and
through colour, and the ease with which the
testa separates from the kernel show them to
be far better than the average sample.

If planters used a definite culture of yeast a
more uniform and thoroughly sweated sample
of beans would be placed upon the market.

246 The Fermentation of Cacao

The cost of cacao yeast would be very small,

or a planter could prepare his own; the
following would be a practical method to be
pursued by.a planter to obtain a yeast culture
in bulk :—
_ To 14 gallons of water are added 4 Ib. of
sugar (preferably glucose) and 1 oz. of a 10
per cent. solution of the plant salts—de.,
magnesium sulphate, calcium sulphate, calcium
phosphate, potassium nitrate, and’ sodium
chloride. This solution could be made up by
any chemist at cost price, 6d. for 10 0z. The
14 gallons are now boiled, poured into a clean
pail and allowed to cool. As soon as. it is
cooled, with a clean spoon two or three beans
are removed from the centre of a mass of
cacao which has been fermenting for three
days and these are stirred into it. The top
of the vessel is now protected by tying over
it a muslin cloth. In a few days there will be
a white layer of yeast upon the surface of the
solution and another at the bottom of the
vessel.

To the beans as they are placed in each
sweating box one pint of the. thoroughly
stirred solution is added, and sweating will
start almost immediately, as shown by the rise
of temperature.

Thus the cost of the yeast would be about
the price of half a pound of sugar ; this would
represent the quantity necessary for about four
bags of cacao. Thus a dozen pounds of sugar

Dr. Lucius Nicholls 247

would be sufficient for the preparation of one
hundred bags of cured beans.

By taking samples each time for the prepara-
tion of the next -yeast the required ferment
could be kept going indefinitely ; but it would
be better to obtain a pure sample for the pre-
paration from a laboratory.

It now has been shown that if cacao is to be
sweated upon scientific principles, the proper
fermenting organisms must be supplied, for in
this way a definite and thorough fermentation
will always take place.

There has been much discussion as to what
is really required in the finished product, which
is placed upon the market ; here the decision
obviously rests with the manufacturers and
those who buy for them: however, it is for the
planter and scientist to point out all probable
possibilities to them.

From the nature of the case the changes
which can be brought about in the interior of
the bean by fermentation have very strict
limitations. There seems to have been a
desire to get rid of the bitter principle; this
appears unnecessary, as it is easily dealt with
by the manufacturers, and can only be removed
in the, whole bean by carrying fermentation to
the stage of putrefaction: that is, when the
organisms themselves are acting in the interior
of the bean and not their enzymes only, as
should be the case in fermentation.

Again, when putrefaction takes place and

248 The Fermentation of Cacao

the bean is dried, the loss of weight is such
that any increased price obtainable is insuffi-
cient to render the process profitable.

The question of temperature must now be
considered. This depends upon several factors,
such as the organisms present, the size of the
sweating- boxes, and, to some extent, upon the
variety of the cacao and the nature of the
season.

The temperature does not rise as high with
yeasts as with some other organisms, and when
it rises to a great height it falls very rapidly.

Yeasts are killed by an exposure to 133° F.;
for one hour at 120° F. the action of zymase
(the ferment of yeast) almost ceases. The
optimum temperature, that is, the heat at which
they flourish best, is well below 110° F. But
a temperature of this degree is undoubtedly
required in, sweating cacao to diffuse the fats
and aid the chemical and physical changes. It
is, therefore, a temperature below 120° F. and
above 110° F., which is the best, for it will
not impede the action of the yeasts, and will
prevent the flourishing of many adventitious
organisms which require a lower temperature.
There are other organisms which raise the
temperature of a sweating mass higher than is
done by the yeasts, and if it is found that a
sweating-box gives 120° F. or more when yeast
cultures are used, it means that there is some
contamination ; the cure of this is the thorough

cleaning of the box.
Anart fram thece factare the anestian of

Dr. Lucius Nicholls 249

temperature is best dealt with by actual experi-
ments to decide the temperature at which the
best sample is produced.

It will be found that the use of yeast cultures
produces a uniform sweating with a uniform
temperature.

Cacao Sweatings..

The juice which runs away from the sweating
beans is on almost all estates allowed to waste.

Mr. Hudson has caiculated that for every
100 bags of 200 lb. which an estate produces
there are 600 gallons of this fluid.

From the nature of the fluid, containing about
12 per cent. of sugar, so far as I can see at
present only two commercial preparations could
be prepared—an alcoholic beverage or an acetic
acid condiment, that is, vinegar. The former
would be extremely difficult to prepare, whereas
a high-class vinegar can be made with ease.

Here, again, much depends upon the pre-
sence of the right organisms, as the following
experiment shows: Four samples of the same
sweatings were placed in equal-sized vessels,
to three were added various cultures of acetic
acid-forming bacilli and cocci, to the fourth
nothing was added (it must be remembered
that acetic acid-producing organisms are always
present in sweatings). The tops of the vessels
were protected by tying cloth over them. At
the end of three weeks they were estimated
for acetic acid; one gave 2°8 per cent., another
3,1 per cent., a third 4’I per cent., and the
last, to which no culture had been added, a*s

250 The Fermentation of Cacao

per cent. The third gave the strongest sample,
and others similar to it could be obtained by
using a small piece of the surface film of
organisms to start the fermentation. Thus
once a good sample is obtained the organisms
from this can,be used to prepare any quantity.

It is desirable to protect all fermenting
sweatings from flies and other insects that are
attracted to it, and also as much as possible
from the higher moulds. The fermentation
should take place in large flat vessels, so as
to have a large surface of fluid for the growth
of micro-organisms as a top layer. After about
two months the vinegar can be decanted off,
strained, and bottled.

The following table shows the comparison
of this vinegar with others sold at the present
time :—

i i riginal sol
ctavity | Exteace | Aegue | Oueetencat | Ash

Wine Vinegar: .

Maximum.:.| ro2zr | 3119 %| 7°58 % | 11 %approx.| 0°68

Minimum...| r'or2 | 1°38 ,, | 4°44 ,, Go ag 0°16
_Mean...| 1017 | 1°93 5, | 633 5,] 85, 55 0°32
Spirit Vinegar:

Maximuim...| 1°013 | 0°57 ,, | 7°89 ,,| 8°54, 55 Trace

Minimum...| 1°008 | 0°16 ,, | 4°93 5, | 5°5 5 38 $5

Mean se | 110082] 0°35 ,, | 6°34,, | 6°2 ,, a 49
Malt Vinegar: |

Maximum...| 1°025 | 3°95 5, | 7°42 ,,] 12,,; a o'74

Minimum .,..| r'or2 | 1°15 ,, | 4°51 3, Gis As 0'25

Mean we] T'org | 1°84, | 5°52 45 Fos wy 0°34
CacaoVinegar:

Maximum...| 1°024 | 24 ,, | 7°75 55 | 104, 6 0°65

Minimum..,| ror§ | 10 ,, | 4°21 ,, 5 a ‘oy Oot

Mean «| I'OIS | 1°74, | 6t2r ,, DP ais 34 0°25

Dr. Lucius Nicholls 251

Cacao vinegar which has been well matured
by keeping is very mellow and of a light
colour, and is undoubtedly equal to most others
on the market. Properly exploited it should
become a considerable asset to the planter,
and if sold at the price of some other vinegars
would well-nigh pay the expenses of cultivation
of an established estate.’

1See footnote, p. 216.-H. H. S.

252

CHAPTER III.

THE LAST WORD.
By the Editor.

As several years on an average have elapsed
since the preceding essays were written, and
at least twelve or thirteen years since Dr.
Axel Preyer recorded. on paper the results
of his investigations, I was most anxious to
hear what each of the authorities had to say
at the present time on the progress made
along the lines advocated by them. This was
especially the case with Dr. Fickendey, as |
had noticed that his name had been mentioned
in the Bulletin of the Imperial Institute in
a lengthy description of a process carried out
under his directions, whereby the fermentation
of the beans had’ been dispensed with, other
means having been taken to kill the embryo
without destroying the oxidizing enzymes. On
this point Dr. Fickendey was good enough, at
the end of March, 1913, to write as follows :—

With the férmentation of cacao there are
two processes that should be kept strictly
separate; on the one hand, the fermentation
of the pulp, z.e., the saccharine and the mucila-

The Last Word 253

ginous mass in which the beans are imbedded,
and on the other the changes that the sub-
stances in the beans themselves undergo.
This can be described as external and internal
fermentation. ;
The juice of the pulp, according to my
investigations, contains about 10 per cent. of
sugar (dextrose and levulose), 3 per cent. of
mucin, and besides this, as much acid (chiefly
malic acid) as corresponds to ~, (1 in 10)
normal solution. The specific gravity at’ 15° C.
amounted to 1'06308, 100 c.cm. of juice con-
tained 0°638 grm. of mineral ash, of which
0'192 grm. consisted of calcium carbonate, and
o'196 grm. magnesium carbonate. After hydro-
lysis of the mucilaginous substances a pentose
and dextrose-were proved to be present. No
difference in the Criollo and Forastero varieties
could be demonstrated as to the composition
of the juice. The. pulp is, therefore, a good
nutritive medium for a large variety of micro-
organisms, both yeasts and bacteria. The
different methods of conducting fermentation
are well enough known. The guiding prin-
ciple is always to turn over the heaps. the
moment the temperature begins to fall, in
order that the micro-organisms may be stimu-
lated to renewed activity by the. advent of
oxygen. In the first place, the sugars are
converted into alcohol, then oxidation fer-
mentation sets in, acids, especially acetic acid,
being formed. Under normal circumstances

254 The Fermentation of Cacao

the acids are then for the greater part oxidized
into water and carbonic acid. If wrongly
conducted the process leads to the production
of fermentation by-products (lactic acid fer-
mentation, butyric acid fermentation), which
have an unfavourable influence on the value of
the product. A considerable variety of micro-
organisms take part in the fermentation; both
yeasts (mycoderma, torula, monilia, saccharo-
myces) and bacteria, of which the acetic acid
bacillus plays a particularly important rdle.
Preyer’ isolated a yeast, Saccharomyces theo-
brome, from fermenting cacao, and has recom-
mended the use of the pure culture of this for
the initiation of the fermentation. This idea has
been repeatedly exploited. Not much success
is, however, to be expected from the use of pure
strains of yeasts. The first essential to success
is lacking, that is, the possibility of sterilizing
the culture medium, for with the death of the
germs the destruction of the enzymes would
be associated, whose action, as we shall see, is
irreplaceable. Without sterilization, pure yeast
cultures. have but little prospect of competing
with wild ones. It often takes some hours
before the contents of the broken cacao pods
reach the fermenting station, and, in the mean-
time, the wild flora, consisting of yeasts and
bacteria, has already started the fermentation.

Now the processes taking place in the
interior of the bean are only indirectly con-

1 Tropenpflanzer, 1901, 5. Jahrgang, p. 151.

The Last Word 255

nected with fermentation. The principal
changes in the bean, that are appreciable to
the eye and taste after fermentation, consist in
a brown colouration of the nibs and a softening
or reduction of the bitter flavour. The object
of fermentation is, in the main, to kill the germ
in the bean in such a manner that the efficiency
of the enzyme is in no way impaired. Behrens
has already pointed this out,’ and this state-
ment is proved to be well founded, in the first
place by the fact that the above-mentioned:
changes fail to occur when the enzymes are
destroyed before fermentation. Thus, if fresh
cacao beans are heated to 100° C., whilst they
will still ferment; the brown colouration and
softening of the bitter taste do not occur.
A further proof is to be found in the fact that
the changes essential to the preparation of
cacao may take place without fermentation, if
the germs in the beans are killed under con-
ditions that leave the enzymes unimpaired.
There are several ways of destroying the life
of the bean without running the risk of destroy-
ing the enzyme. If there were any financial
value in doing so, such methods could be used
in the practical or commercial preparation of
cacao. In every case the first process consists
in the removal of the pulp. It is unnecessary
to completely separate the pulp from the
beans, in fact it suffices if one washes out the

1 Lafar, ‘Handbuch der technischen Mykologie,”
Bd. i, p. 655.

256 The Fermentation of Cacao

dissolved substances (sugar and acid), which
can be done by: mechanical means without
any difficulty:

The various methods consist of :—

(1) Mechanical Means. —,The beans are
crushed and,.then dried. A brown mass com-
pletely free from bitter taste would thus be
obtained, but buyers are very unlikely to buy
such a powder.

(2) Chemical Means.—F¥or commercial pur-
poses only non-poisonous and volatile chemi-
cal substances can be used here. Alcohol
fulfils both these requirements. The beans
are laid for ten minutes in 96 per cent. alcohol,
and then kept for five to six days over alcohol.
They are then placed for one minute in water,
and afterwards dried. A large cacao manufac-
turer in Germany has expressed the following
opinion about cacao prepared in this manner:
“This alcohol treatment denotes a great
advance in Cameroons cacao, as compared
with beans prepared by the ordinary process.”

(3) Change of Temperature.—The vitality of
the cacao bean depends on its being kept
within definite limits of temperature; over-
stepping these limits in either direction leads
to the death of the bean—z.e., of the germ.
From a practical point of view it would appear
that the easiest way to kill the germ is by heat.
The protoplasm, the real life-bearing substance,
is devitalized in the cacao bean at a temperature
that lies below that which destroys the enzyme.

The Last Word 257

In the case of fermentation the devitalization
is mainly brought about by the development
of heat. It is thus possible to combine drying
and devitalizing in one procedure if the drying
be carried out at a definite temperature (about
50° to 60° C.); or, again, if it be deemed
desirable to sun-dry the beans, this may be
done after first subjecting them for one day
to a temperature of 50° to 60° C. Labora-
tory experiments—which, however, one must
own never represent a true imitation of what
takes place on a wholesale or commercial basis—
gave good results, provided only that fully ripe
beans were used. Further attention must be
called to the fact that the finer varieties, such
as Criollo, more easily become brown and free
from the bitter taste’ than the commoner
Forastero. Another method is the devitaliza-
tion by cold. It is not necessary to actually
freeze the beans; maintaining them for three
hours at 1°C. is quite sufficient. On drying
them after this, brown colouration and simul-
taneous loss of the bitter flavour take place
on access of air. A manufacturer writes as
follows about beans treated in this way:
“The beans devitalized by freezing have the
strongest flavour, and possess a full and pure
cacao aroma, such as we have never yet met
with in any other kind of bean.”

1 For one redson, because the bitter taste is not
there to the degree that it is in the Forastero kinds.—
H.H.S.

17

258 The Fermentation of Cacao

The. Bulletin of the Imperial Institute (vol. x,
No. 2, July, 1912) includes an interesting
article on the preparation of West African
cacao (pp. 239-247). On p. 243, when dis-
cussing certain experiments which have been
carried: out in that Colony in preparing beans
for market without fermentation, the report
tells us: “In preparing cacao beans for market,
fermentation is usually resorted to, and for this
purpose the beans and adherent pulp, after
being removed from the pod, are placed in a
vat or other receptacle where micro-organisms
bring about fermentation, the temperature of
the mass rising from 30° to 50°C. The germ
of the bean is killed in this process, and at the
same time the astringent matter in the fresh
bean is destroyed to a great extent, and the
colour changes from a purplish hue to a rich
brown. The chief object of this process is to
kill the bean without injuring the enzymes,
probably chiefly oxidases, which are stated to
be the real means of reducing the bitterness
and altering the colour, for which reason the
beans are frequently turned to keep the
temperature below 60° C.

‘Several new methods of bringing about
these changes have been proposed. Dr.
Fickendey, Victoria, Cameroons, has sug-
gested that the beans should be subjected,
after removal of the pulp, to changes of tem-
perature, either by heating them to 50° or
60° C. (122° or 140° F.) for twenty-four hours,

The Last Word 259

or by keeping them at a temperature of 0° to
1° C. (32° to 33°8° F.) for three hours. The
cooling method was applied experimentally in
the Cameroons, and the beans produced by
this method were stated by a German firm of
manufacturers to possess a good aroma and
flavour.”

And again on p. 247, in summing up the
results of various experiments, and the reports
of brokers and manufacturers on cacao pre-
pared by the various methods, the Imperial
Institute tells us: “It is clear from the fore-
going statements that both brokers and manu-
facturers regard the fermented cacao (Nos. 1
and 2) as superior to the three unfermented
samples (Nos. 3, 4,.and 5). With reference
to the latter, it will be noticed that the valua-
tions of Nos. 3 and 4, treated by Fickendey’s
processes; are in all cases higher than those
of No. 5,1 which were merely washed and

London Brokers’ | Liverpool Brokers’ | Manufacturers’
1 Sample Valuation Valuation Valuation
« (Feb. 11, 1911) (Feb. 15, 1911) | (Feb. 15, 1911)
Per cwt. Per cwt. Per cwt.
No. 1 | About 54s.to55s.| 50s. to 51s. | 528. to 538.
1 2 53S. 49S. 5, 50S. 52S. 5, 53S.
oo 3 9 528% "| 478. 5, 48s. 48s.
soe » = 538. 46s. ,, 47S. | 508.
ii 5 » 508. 45s. 5, 468. | 46s. to 48s.

Values placed by the different centres will always
vary, as the terms and conditions of sales are not the
same.

260 The Fermentation of Cacao

dried. The Bulleten included a description of
the samples, showing that Nos. 3 and 4 have
undergone, to some extent, that change in
colour and flavour which is usually regarded as
resulting from fermentation, so that the results
of these experiments tend to support Ficken-
dey’s contention that fermentation of cacao
may be dispensed with, proviided that other
means are taken to kill the embryo without
destroying the oxidizing enzymes which are
believed to produce the changes in colour and
flavour.”

Brown colouration and loss of bitterness
therefore bring about the changes in the beans.
The bitter taste is due to the presence of
tannic substances, and the brown colouration
is due to a change in, viz., the oxidation
of, these substances. If a cacao-bean whose
enzymes are unimpaired be cut through, the
exposed surface turns brown. This is a result
generally met with in all fruits containing
tannin, é.g., apples, and is due to oxidation of
the tannins. We should here mention the be-
haviour of the common sloe (Prunus spinosa),
which in many respects resembles cacao. The
ordinary sloe has such an acrid bitter taste
that it is unpalatable, but after a frost the cells
of the fruit pulp die and the enzymes are then
able to develop their activity. The result is
that the acidity disappears and the fruit be-
comes palatable. In this case also, the loss
of the acrid taste is accompanied by brown

The Last Word 261

discolouration, and the cause of this change in
colour is brought about by the oxidation of the
tannic substances (possibly preceded by a split-
ting up of glucosides).

It has often been.suggested that oxidases
may play a part in the preparation of cacao.
Indeed, it is easy to prove that such is the
case. The oxidation of the tannin in other
fruits containing that substance is also put
down to oxidase. If fresh, decorticated cacao-
beans are crushed in water, the watery extract
gives a blue colour reaction with tincture of
guaiacol, and a dark blue reaction with an
aqueous solution of tetramethyl-paraphenylen-
diamin hydrochloride. These reactions are
best obtained by the capillary method of
J. Gruess.’

The oxidase action may be demonstrated
without the aid of foreign chemical substances.
If cacao-beans be: heated in water to 75° C.
and then crushed, no change in colour and no
reduction of the bitter taste is produced in the
mass, whilst brown discolouration still occurs
after heating at 7o* C. for an hour. The
browning of the beans heated to 70° C. can
still be obtained if a small amount of aqueous
extract of fresh cacao-beans be stirred-into the
mass. For comparison, another portion of
the mass may be treated with a similar extract
previously heated to 80° to 100° C.; in this

1 *¢ Bericht der deutschen botanischen Gesellschaft,”
Bd. xxvi, p. 624.

262 The Fermentation of Cacao

case the brown colouration does not oécur. If
the paste of stewed or boiled (gekochten)
beans mixed with the extract of fresh beans
be placed in tubes having a small surface,
the browning commences at the surface, and
gradually passes to the deeper parts as the air
gains access.

If the beans be boiled (Aoch2) in water the
tannic substances go into solution. This solu-
tion also turns brown, owing to oxidation, if
a small quantity of the above-mentioned
extract be added to it. A purified solution of
tannin (precipitation with lead acetate, filtering,
breaking up of the lead compound by hydrogen
sulphide) also turns brown if the extract of
fresh beans be added, the colouration commenc-
ing on the surface. All these facts force one
to the view that oxidase takes a part in the
browning, z.e., by bringing about the oxidation
of the tannin in cacao-beans.’

About 50 grm.. of decorticated beans devital-
ized by freezing were broken up and placed
in a gas-tight flask. This was shaken several
times, and the gases contained in it were
examined. The result of the analysis was as

follows :—
|

1 The watery extract of boiled cacao-beans can he
used very well on the other hand, to prove the presence
of oxidase, a fact probably first pointed out by Gruess.
This extract is, for instance, stained deep brown by the
addition of Castilloa milk, which contains a powerful
oxidase. In place of the watery extract, the alcoholic
may also be used, but it must first be deprived of fats.

The Last Word 263

Carbonic acid, 4°5 per cent.

Oxygen, 12°8 per cent.

Nitrogen, 82°7 per cent.

A simple calculation shows that for every
two unit-volumes of oxygen used up, one unit-
volume of carbonic acid has been formed,
Experiments conducted on parallel lines led
to the same results. One may _ probably
gather from this that oxidation is associated
with a breaking up and giving off of carbon
dioxide (Kohlenstoffabspaltung).

Whether the oxidation is preceded by a
splitting off of glucosides has not been definitely
determined. Lazarus certainly affirms that a
glucoside (cacaonine) occurs in fresh beans,
being composed of sugar, cacao-red and
the alkaloids caffeine and theobromine.'
Schweitzer? has confirmed this, and also iso-
lated an enzyme capable of splitting glucoside.
These experiments require repeating and
checking, however.

The behaviour of the beans having white
nibs differs from that of those with bluish-red °
cotyledons, in that the devitalizing temperature
of the oxidase stands at about 5° to 10° C.
higher. In other respects the conditions are
the same. The tannin-containing cells of the
white beans are just as much developed, as
may be shown by treating sections with tannin

1 Review, Botanisches Centralblatt, 1893, Bd.. Ilvi,
p. 296.
: Pusamwactittioh Zeitung, 1898, Bd. xliii, p. 381.

264 The Fermentation of Cacao
reagents. In the case of the bluish-red beans
the tannin-containing cells can be recognized
microscopically by the presence of the bluish-red°
colouring matter, which is also of a tannin nature.
A few words may be added with reference
to the washing and’ drying processes. The
washing of the beans after fermentation has
been entirely given up in the Cameroons. The
loss amounted to about 8 to 10 per cent. with-
out adding to the price realized by the product.
The best method of drying is by the sun.
Such a process works slowly, so that the air
has time to penetrate into the bean and to
complete the process of oxidation; and it
further takes place at a temperature that in
no way impairs the action of the enzymes—it
is on this point that the greatest stress should
be laid in connection with the various mech-
anical drying processes. If the enzymes are
dcaroved by using temperatures that are too
high, it becomes impossible for the manufacturer
later on to remedy any faults made by the
planter. The drying method most commonly
used is that of drying houses fitted with trays
placed one over the other, z.¢., in tiers, through
which currents of hot air pass. These build-
ings are a great advantage if the temperature
is not allowed to rise too high, but if the heat
is too great the cacao deteriorates. The intro-
duction of fans obviates. this evil. The ac-
celeration of the currents of air, as by fans,
would prevent excessive temperatures existing.

The Last Word 265

It is very doubtful whether, with the present
class of manufactured cacao that is in demand
it is worth the planter’s while to improve the
quality of their beans, provided that they can
ship them even in quality, size, appearance and
“break,” and the following reasons can be
advanced against incurring unnecessary ex-
pense to improve the class. of ‘bean shipped
at present (provided always the bulk runs
even as just mentioned) :—

(1) The cacao-market has an _ increasing
tendency to minimize the differences in price
between the good and ordinary cacaos. Ten
years ago the proportional value between the
Cameroons and Caracas beans was as 100 to
240 approximately ; now it stands at about
100 to 140. Even granted that the quality of
Caracas cacao may have deteriorated some- ,
what, and that of the Cameroons cacao may
have improved, the tendency to level down
or up all kinds, already spoken of, is un-
mistakeable.

(2) There is no recognized general standard
as to the quality of a cacao, and there is also
no uniformity of opinion as to what constitutes
an ideal bean as to quality. Since flavour is
the main guide, the valuation of the same cacao
may differ very markedly according to the
different experts sampling it; on-this account
the broker who settles the price as a rule
judges quite differently to the manufacturer.’

1 Do we find this in London ?>—H. H. S.

266 The Fermentation of Cacao

Carelessly or insufficiently fermented beans
often obtain a better price than those which
have been properly cured.'

(3) The outer appearance of the bean seems
to have at least as much to do with the price
as the intrinsic quality.

_ For this reason the investigations relative
to the fermentation of cacao and the experi-
ments to improve the quality of the beans
have been abandoned at the experimental.
station in Victoria, Cameroons, since 1909.”

At the same time, or soon after writing the
foregoing remarks, Dr. Fickendey thus re-
viewed and discussed the situation generally,
as it occurred to him after scanning the various
essays which we had sent him, These did
not include Dr. Sack’s, as his essay was not
received until some little time after I had
written to Dr. Fickendey, in the Cameroons.

I have pleasure in acceding to the request
of the Editor of Tropical Life to make a few
remarks on the treatises in this book on cacao’
fermentation.

1 Because being of a more ‘‘ neutral” flavour it can
be used in mixtures or ‘‘ foundation” cacao, where a
full flavoured bean would not do, as it would alter the
taste.—H. H. S.

? Probably because that class of cacao, as shipped at
present, is able to compete successfully with the other
African kinds, or cacao from Bahia, San Domingo, &c.,
and this discourages any systematic efforts to improve:
the beans, especially as doing so would tend to reduce
the weight, and increase the cost of production.—
H.H.S.

The Last Word 267

Dr. Axel Preyer’s work constitutes a first
attempt to explain the entire process, its
aim and import. Preyer considers enzymes
derived from yeasts responsible for the
changes occurring during the fermentation.
Although I do not find this explanation to be
correct, for I maintain that it is the enzymes
of the beans themselves that cause the changes,
his work is still of value, and it certainly gave
the impetus to further investigations.

Preyer also succeeded in isolating a special
variety of yeast, to which he has given the
name of Saccharomyces theobrome, which was
always found to be present on fermenting
cacao in Ceylon, and is claimed to produce a
particularly high quality cacao. Experiments
conducted with pure cultures of this yeast
in Victoria (Cameroons) in 1900 did not yield
satisfactory results however. This lack of
success was perhaps due to the yeast having
died during its transport from Ceylon to
Victoria.

The fine work of Loew has only now
become known to me. Loew regards the
removal of the pulp as the main object of the
fermentation or sweating process. With this
I cannot agree; the loosening of the connec-
tion between the bean and its envelope, z.z.,
between the cotyledons and the testa or shell,
is also of no essential importance, for roasting
in all cases easily separates the shell from
the kernel. The essentially important changes

268 The Fermentation of Cacao

occurring during fermentation may be con-
sidered as being the brown colouration and
the reduction of the bitter taste of the nibs.
I am pleased to find that Loew, in explain-
ing this change, arrived in the main at the
same, conclusions that I did in my investiga-
tions undertaken a year later. There is one
point in which Loew’s results differ from mine.
According to him the oxidase is insoluble,
whilst I have regarded it as soluble. In my
experiments I used an extract of fresh beans,
which were crushed under water so as to
delay oxidation. The filtrate was never clear,
and it is therefore possible that the substance
causing the cloudiness contained the oxidase.
In order to clear up the divergence the follow-
ing experiment was made. Fifteen beans.
were broken up in an atmosphere containing
carbonic acid and then covered with boiled
water. This was then filtered in a similar
atmosphere. The filtrate was at first cloudy,
but soon ran off clear. The clear, reddisl-
violet solution gave a marked oxidase reaction.
Brought into contact with oxygen containing
air it soon turned brown and became clouded,
owing to precipitation of tannins. This brown
solution showed a very much weaker reaction
with oxidase reagents. If a few drops were
allowed to fall on blotting-paper and a solution
was added of, say, for instance, tetramethyl-
paraphenylen-diamin-hydrochloride, the most
marked blue reaction occurred in the centre,

The Last Word . 269

7.€., where the precipitate had been mainly
deposited. The deduction from this experi-
ment would appear to be that the oxidase is
soluble in water, but is carried dewn with the
tannin precipitate and thus rendered insoluble.

As regards Dr. Schulte im Hofe’s process,
the last word has in my opinion not yet been
spoken. The method is not new in itself, and
has already been used for a long time in a
good many cacao estate factories in completing
the ripening process of the beans. It is more
a question of the plant or machinery required.
If it be possible to devise an apparatus which
permits of the process being carried out
cheaply and can be easily controlled, there is
some prospect of the method being applied on
a large scale.’

The prize essays of Nicholls and Hudson
offer a useful stimulus and contain new and
interesting facts.

I cannot regard the proposal, that the small
farmers should be forbidden to sell fresh cacao
in order that thefts may thereby be avoided,
as being of any practical value. In the
Cameroons the tendency is, on the contrary, to
encourage the natives to sell the fresh cacao so
as to help exporters to obtain a better quality,
as doing so enables the cacao to be treated in
an expert manner by the European shippers.
Thieving takes place all over the world, and
the task of protecting himself against thefts
devolves on the proprietor. Should special

270 The Fermentation of Cacao

legislative enactments become necessary to
prevent cacao thefts, it will surely be sufficient
if the traffic in fresh cacao be controlled by
demanding certificates of origin.’

The proportional weight of fresh to cured
and dried cacao will vary considerably accord-
ing to the variety of cacao and the country in
which it is grown; also, Messrs. Mackinnon
and Co. inform us, according to the machine
used. This firm claims that its machines
effectually dry the produce, cacao or coffee,
with the minimum loss in weight. In the
Cameroons the cacao produced is principally
of the Forastero type, and in that case 100
parts of fresh beans yield 45 to 50 parts of
dried cacao,

The best cacao is undoubtedly obtained by
sun-drying. It will, however, be impossible,
except in a few instances, to do without
artificial drying plants.

Theoretically a plant constructed on the
principle of bringing the produce into contact
with opposing currents of air (Gegenstront)
should be the cheapest to work. The diffi-
culty is, however, that the cacao dries very
irregularly. The individual beans adhere to
one another, and at the points of contact the

11 believe the German methods of handling and
punishing the natives living under their authority are
capable of rendering many laws to be unnecessary
which we, in our own Colonies, have thought better to
put into force.—H. H. S. e

The Last Word o7y

drying ceases or -becomes delayed. It there-
fore becomes necessary to stir and turn the
mass frequently, thereby interrupting the con-
tinuous working. So far as I can judge by
experience, I consider a drying-house supplied
with ventilators or fans and rows of trays the
most practical method for carrying out the
drying process.

It is very doubtful whether the juice of the
pulp can be utilized for the manufacture of
vinegar, since, at least under the conditions
prevailing in the Cameroons, a very large part
of the juice runs off before the cacao reaches
the fermenting boxes.

According to Nicholls the changes brought
about in the interior of the bean are produced
by enzymes formed on its exterior; in this view
he coincides with Preyer. The statement can,
however, hardly be substantiated.

The “cacao-fly” or some similar insect also
occurs in the Cameroons, as it probably does
in all tropical countries. It is always to be
found on fermenting saccharine fruits. That
it plays an important réle in carrying the
yeasts is a new and valuable observation for
which we have to thank Nicholls. _

Nicholls’s proposal, that yeast should be
added to the cacao from the first, seems
worthy of consideration and of further inves-
tigation. Contrary to what Preyer aims at,
he does not lay so much stress on using a
pure culture (cultivated yeasts) as on increasing

579 The Fermentation of Cacao

the total amount of yeast employed. It would
seem very probable that the quality of the
cacao might be improved if an active fermenta-
tion could be induced from the first.

Dr. Schulte im Hofe, of- Berlin, by the
following remarks tends to show that he, whilst
not disagreeing with Preyer and Nicholls, is

Ly courtesy of the Bulletin of Entomological Research.”

CACAO-FLY (Drosophila melanogaster), Mg. * 16; see also
Dr. NICHOLLS’s Essay.

more of accord with Dr. Fickendey, since he
wrote thus :—

Dr. Preyer is of the opinion that the fer-
mentation with yeast is the most important
factor in the process of cacao fermentation,
and maintains that the cleaner the yeast the
better the quality of the beans. He considers

The Last Word 29%

that, for this work, the yeast Saccharomyces
theobrome to be the most suitable, and main-
tains that an acid fermentation would be
harmful.

Dr. Nicholls likewise considers the fer-
mentation with yeast the most important part
of the process of cacao fermentation, but
he also attaches importance to the penetration
of the zymose formed by the yeast into the
interior of the beans, which transforms the
sugar contained therein into alcohol and car-
bonic acid. Nicholls certainly recognizes that
in the process of fermentation the bitter
substance is reduced, but considers this of
secondary importance, and that it is more
to the purpose to leave the removal of
the bitter substances to the chocolate manu-
facturers.

In my work dealing with the removal of
the bitter (astringent) substances, I consider
this portion of the entire process to be the
most important and critical for obtaining good
cacao. The alcoholic and acetic acid fermen-
tation is, in my opinion, of secondary import-
ance. By means of this, the pulp should be
removed by the cheapest and most simple
manner, the life of the bean killed (which is
done), and the bean itself is mildly acidulated.
The acid effects (as also with tea) that the
bean is subjected to in the process of oxidation
which follows the fermentation causes it to
better withstand the influence of harmful

18

274 The Fermentation of Cacao

bacteria. . The acid is further essential to
obtain a cacao of the best possible quality.
. De Fickendey proves the presence of an
enzyme which causes the oxidation, and like-
wise considers the killing of the bean, and the:
process of oxidation following thereon; as the
most essential part of the fermentation.. In
order to accelerate the oxidation of the bitter
(astringent) substances, Fickendey recommends
‘that the beans should be treated after sues
tation with a diluted solution of potash, in
order to accelerate the oxidation by nettle
ing the acid. Very bitter and sour beans are,
-as is well known, submitted to a similar pinzcs
in chocolate manufactories.
Preyer and Nicholls therefore regard. the
most important period in the process as being
when the beans are fermented with yeast, and
attach no value to the conversion of the astrin-
gent substances contained in the beans. |
-myself, and after me, Fickendey, attach the
chief importance to the oe of the.
astringent substances. But whereas I regard
it as necessary to submit the sour or. acid-,
tasting beans to oxidation in order to obtain
a good quality, Fickendey believes that. better
results can be obtained by the oxidation of the
beans previously treated with potash in which
the acid has-been neutralized. :
Dr. Oscar Loew confined his remarks to the
prize essays of Mr. Hudson and Dr. Nicholls.
This was due, I believe, to the fact that these

The Last Word 275

notes were written in Munich on February 18,
1913, before the other essays had been trans-
lated and put into type. According to Dr.
Loew, there can hardly exist any doubt that
the fermentation of cacao was originally prac-
tised solely for the purpose of loosening the
substances to be found between the pulp and
the seed-coat. This leads to a ready removal
‘of the attached pulp tissue, and thus a rapid
drying process is insured, which is necessary
in order to prevent the seeds becoming
mouldy.

At the same time, however, changes in the
cotyledons of the seed are produced during the
fermentation, which finally lead to the develop-
ment of the aroma. The chemical nature of
this aroma has not yet been decided. It may
be an ether-like compound or a ketone, or
an aldehyde of the aromatic series, like e.g.,
vanillin is. It would be an object of con-
siderable interest to reveal the mother sub-
stance of the fine flavour peculiar to cacao.

So far the most important report on the
subject, from a practical standpoint, is that of
Mr. Hudson in the prize essay on the “ Fer-
mentation, Curing and By- products of Cacao.”
An experience of twenty years’ cacao fermen-
tation has been made careful use of and pre-
sented for our consideration. In regard to
the aroma, this report contains a sentence of
special importance, viz. : “ The higher the tem-
perature attained and maintained for some days

276 The Fermentation of Cacao

by primary natural fermentation, the better the
class of cacao turned out.”

It seems to the writer that the effect of this
temperature consists in promoting the action
of a certain enzyme within the seed, splitting a
glucoside in such a manner that afterwards, in
drying and roasting, the development of a
high-grade aroma is possible from one of the
products thus broken up.

This is more probable than the formation
of an ether-like compound by means of the
alcohol produced by the yeast, since the fer-
menting liquid does not penetrate the seed.

As to how the fermentation should be
started, the proposal of Dr. Nicholls to: infect
the pulped cacao with yeast and to add mineral
nutrients in order to insure a rapid growth and
multiplication of the yeast cells, is no doubt a
good idea. In the opinion of the writer, the
infection with a pure culture of Saccharomyces.
ellipsoideus would suit just as well as the infec-
tion with one of S. ¢heobrome. In fact the
writer has discerned in Porto Rico only S.
ellipsoideus and S. apiculatus in a lot of fer-.
menting cacao beans.

Dr. Lucius Nicholls having read the trans-
lation of Dr. Schulte im Hofe’s essay, wrote me
that he could not altogether agree with his
opinion, and then goes on to say :—

Oxidation of the interior of the bean naturally
takes place, but the action is brought about by

1 See p. 177.

‘Lhe Last Word 277

oxidases, and these ferments are present in
yeasts and other organisms and also in all seeds,
for they produce changes which are necessary
for germination. Apparently Dr. Schulte con-
siders that all the oxidation takes place without
any catalytic agent or ferment, but this is highly
improbable, and his experiments certainly do
not prove it. The same as with tobacco and
tea, the fermentation is due to enzymes,
either naturally present or due to organisms,
and before one can test the changes occurring
without the presence of these, they must be
isolated from the rest of the constituents, and
this is practically impossible without altering
the cacao beyond all recognition.

Last, but by no means least, we come to
Dr. Axel Preyer, whose work was carried on
during the closing years of last century, and,
as stated, published in Der Tvropenpflanzer
of April, 1901. Now, on April 7, 1913, or
just twelve years later, Dr. Preyer writes from
Venice, where he holds the position of German
Consul, as follows :-— .

‘Tt is with considerable pleasure that I accede
to the request of the Editor of Zropzcal Life,
Mr. H. Hamel Smith, to add a few words to
my old essay on ‘Cacao Fermentation.’
Although, as I state in. the concluding para-
graph of this essay, which was published in
Der Tropenpflanzer, No. 4, of April, 1901, I
have, in the above communication, given some
details regarding the causes of fermentation

278 The Fermentation of Cacao

and the methods employed to induce feér-
mentation in cacao, there still remains a diff-
cult but important point to be solved, viz.,
the recognition of the chemical changes that
take place during the fermentation and drying,
and of the intermediary and final substances
formed during the process. It would still be
too risky, before even the composition of the
fresh cacao bean in its various parts is fully
known, to wish to advance chemical hypo-
theses about the processes and changes that
take place during the process of fermentation ;
but it is very probable that, later on, the
chemist will play an important part in the
preparation of cacao. on the estates.
‘Although the above was written nearly
thirteen years ago, I am afraid that | have
not much to say now, as the chemzcal side of
the problem, on which I touched towards the
end of my essay, has so far not been elucidated
by any new researches. This is, in my opinion,
a pity, because in cacao (as well as in coffee)
fermentation the chemical changes in the
beans are certainly most important factors for
those who are striving to improve the market
quality of the produce and prices to be obtained
by it, whilst ignorance of the nature of these
changes makes further improvement of the
planters’ present methods difficult.
“Nevertheless, I would suggest that the
question of cacao-yeast cultivation, which has
been examined by several of the authors,

The Last Word 279:

be followed up most carefully. Probably the’
cacao-yeast of Ceylon would not. thrive well:
in other tropical countries, if it met with other.
kinds of competing yeasts or bacilli, but I:
am sure that in every cacao-producing country.
a variety of yeast is to be found and isolated
in pure cultures, which would facilitate ithe -
preparation of a first-class quality of cacao
beans, provided the right methods of fermenta-
tion are followed, viz., tank arrangements, -
temperature, duration, access of air, and pro-
tection against bacilli infection. The resulting”
qualities of cacao may all be good, although
in the same way as with the wine and beer
fermentation in different countries of the world,
différences of colour, flavour, &c., of the cacao
of the East or West Indies, of the Cameroons,
or Ecuador will always be noticeable. But,
to the planter, the problem is limited to the
question as to how he can best produce a good, -
high-priced cacao in an economical way, given
the natural conditions of his country. Well,
on this question my reply is—by using a good,
pure culture of cacao-yeast, produced in the
same country as where the cacao is grown,
and in carefully giving this yeast the best
conditions individually suited to it for fer-
mentation.”

I can only conclude by echoing Dr. Preyer’s «
suggestion that the whole question of cacao
(coffee, tea, tobacco, &c.) fermentation be care-
fully considered and followed up by experts

280 The Fermentation of Cacao

and planters alike, and then put to practical
tests until a certain method is evolved by
which all planters at each centre can prepare
their beans or other produce in such a way
that it can be bulked and sold to type for
shipment, no matter whether produced by a
dozen large estates or a hundred small ones.
This is a time of standardization, of big con-
cerns and large orders ; those planters, there-
.fore, who want to secure the full value of their
produce must give the buyers the type of
cacao, or other produce that they, the buyers,
want, and not what is easiest for the estates to
to turn out.

Having done with these criticisms, I would
like to call your attention to the following which
appeared in the West Indian Agricultural
News of March 15, 1913, p. 91. When speak-
ing of the nature of cacao fermentation, we are
told that recently communicated to the Chemi-
cal Society and published in their journal for
November, tg12, is an important paper by
Bainbridge and Davies (of Messrs. Rowntree
and Co., Ltd.) entitled “The Essential Oil
of Cacao,”

Much of the information it contains is purely
of scientific interest, but those matters dealt
with which are likely to prove useful and
interesting to the cacao grower have been
abstracted as follows :—

The essential oil was obtained in the investi-
gation by the distillation of cacao nibs. It

The Last Word 281

possesses an intense odour of cacao, and the
flavour was clearly perceptible in a dilution of
1 in 50 million parts of dilute syrup. The
flavour is most nearly akin to that of coriander
oil. Itis pointed out that in the method of
preparing cacao beans in the Tropics by fermen-
tation and slow drying, a number of possible
ethereal substances are added naturally to the
crude oil. To explain this, a description is
given of the different fermentation changes,
as investigated by one of the authors in the
West Indies.

The first runnings from the fermenting box
contain alcohol, invert sugar and tartaric acid.
Part of this liquor penetrates into the beans,
but the shell membrane is fine enough to pre-
vent the micro-organisms, which lead to the
production of these substances, from percolat-
ing to the kernels.

During the first twenty-four hours of fermen-
tation the temperature rises to 35° or 40° C.,
varying with the exact position of the box.
Within forty-eight hours it rises to 40° to 45°C,
and if the fermentation is continued for five
or six days, the temperature will be found to
rise to a maximum of 45° to 50° C. Higher
temperatures are occasionally noted when the
fermentation is continued for an exceptionally
long period, for instance, ten to eleven days, as
in Trinidad. In this case, however, the tem-
perature will fall towards the close.

The bi-chemical nature of the different
changes is explained as follows :—

282 The Fermentation of Cacao

(1) A large growth of Saccharomycetes apicu-
latus (“ yeast ”) together with small quantities
of S. anomalus, doubtless derived from the
surface of the pod husks. This stage lasts
about twelve hours.

(2) As in- spontaneous wine fermentation,
an enormous development of true Saccharo-
mycetes occurs. If the temperature rises there
will be no formation of new cells after the
first forty-eight hours. The alcohol prodyced
soon arrests the growth of S. apzculatus and
“wild” yeasts. A quantity of alcoholic liquor
drains away.

(3) Acetic acid fermentation occurs. This
is caused by Baczllus acetz brought in great
numbers by swarms of the “vinegar fly”
fDrosmphile, If the temperature does not
rise above 50° C., the acetic bacteria con-
tinue to grow during the remainder of the
fermentation.

(4) Finally, if the fermentation is prolonged’
beyond eight days, a growth of spore-bearing
bacilli of the Baczllus subtcls ty pe will take place.

In continuation the authors state: “It is
obvious that a number of the products result-
ing from these complex fermentations will per--
colate into the bean, and of these the less
volatile constituents will remain on the dry
kernel. Consequently we shall expect to find
that the true essential oil of cacao is accom-
panied by a certain number of esters and
higher alcohols, analogous to those produced

The Last Word 283,

in other spontaneous fruit fermentations taking:
place at comparatively high temperatures in
the presence of a free supply of air.”

After describing the chemical and physical
properties of the essential oil and other
volatile products of cacao, the paper concludes
with a summary, part of which is reproduced
as follows :—

‘“(1) The aromatic principle of the cacao
bean is an essential oil; (2) two thousand
kilos of cacao nibs (deprived of some cacao
butter) gave a yield of 24 cc. of purified oil
with a very powerful aroma and flavour of
cacao; (3) the oil was fractionally distilled
three times and the third distillation yielded
seven fractions; (4) the early fractions were
rich in esters, divided in all probability from
the fermentation of the cacao bean; (5) the
middle fractions were rich in d@-linalool, corre-
sponding closely with coriandrol. The total
linalool represents more than 50 per cent. of
the cacao oil.”

As the question of cacao oil is here intro-
duced the following, taken from the Journal
of Chemical Technology for December, may be
of interest :—

“Duyck (Aun. de Chim. Anal., Novem-
ber 17, 1912, p. 405). A summary of experi-
ments on various methods for detecting
adulteration in cacao butter. The official
French method demands ' the determination of
(a) the temperature of solution in absolute,

284 The Fermentation of Cacao

alcohol; (4) the saponification number ; (c)
the iodine value; (d) the volatile insoluble
acids. The author also determines the acidity
of the sample. In German tests the refracto-
meter index, the melting point, and Bjork-
lund’s test are also required. Robin detects
coco-nut oil (5 per cent.) by finding the solu-
bility in alcoho! (55°5°) and comparing the.
co-efficient obtained with the saponification
number. For pure cacao butter the constant
lies between 7° and 8°, but is considerably de-
creased in presence of very small amounts of
coco-nut oil (Axx. de Chim. Anatl., 1906, p. 454,
1907, pp. 14, 40, 87, 181). Coco-nut fat gives
a figure of 15 to 18 (cc. N/to NaOH for
5 grm.) for volatile soluble acids, considerably
higher than that for cacao butter, and at the
same time raises the saponification number
and lowers the refractive index and the iodine
figure. Byjorklund’s ether solubility test is
valuable for the detection of wax, margarine,
and paraffin, especially when the melting-point
also is taken of the fat which is deposited, on

cooling the solution too. This melting-point ..

should not exceed 30°. The acidity of com-
mercial cacao butter, when not rancid, is not
greater than o'5 per cent., expressed as oleic
acid. Cacao butter is also adulterated by the
addition of fat from the pellicle and other
waste parts of the plant. This fat is less
aromatic than the true ‘butter’ and rapidly
becomes rancid. It is hardly possible to detect
this adulterant with certainty.”

285

CHAPTER. IX.

A FEW NOTES ON THE CURING AND
FERMENTING OF TOBACCO.

By the Editor.

As the question of tobacco fermentation has
been touched upon by Dr. Schulte and other
writers, the following notes may be of use to
those interested in tobacco production either as
a main or a subsidiary crop, as well as to
planters generally, to compare with the various
processes involved in preparing their crops for
market.

“There are many styles of houses used for
tobacco, depending upon the method of curing.”
Thus reports Mr. J. N. Harper, M. Agr.,
Director of the Agricultural Experiment
Station, Clemson College, S.C. ‘‘ The flue-
cured tobacco is cured in a house that can be
made almost airtight, with a ventilator in the
top which can be closed. The Virginia bright
leaf is curedin this way. The White Burley is
cured entirely without artificial heat, requiring
from five to six weeks in its curing. Barns in
which tobacco is air-cured should have lateral,
horizontal ventilators rather than perpendicular

286 The Fermentation of Cacao

ones, because the tobacco is not so liable to
house-burn. The flue-cured tobacco requires
only a few days for its curing. After tobacco
has been thoroughly cured, it should be stripped
and sorted into different grades, and after a
certain time it should be put down in bulk for
fermentation. Fermenting tobacco is an art,
and the process is due to enzymes rather than
to bacteria as was once thought. These
enzymes are destroyed when the temperature
of the tobacco is raised above 152° F. Before
tobacco is placed in hogsheads it should be
dried out so that it will contain about 11 per
cent, moisture. Fermentation takes place
more rapidly at a high temperature than at a
low one. The stripping, grading and sorting
should be done only by an expert. - The dark, °
heavy export tobaccos are cured in close barns
by an open fire under the tobacco and require
close attention during all of the stages of
curing. It is possible to cure the tobacco a
bright yellow or a dark mahogany by. simply
varying the temperature, the humidity of the
atmosphere, and the length of time in curing.”

Mr. Charles R. Jones warns us, in the article
he contributed to the Phzlippine Journal of
Science, Manila, P.I. (vol. viii, Section D.,
No. 1, February, 1913, p. 27), on the tobacco
or cigarette beetle (Laszoderma serricorne,
Fabr.), that with open mandalas, or fermenting
piles (see illustration, fig. 1), where the beetles
have free access to the leaves, they do incalcu-

Curing and Fermenting Tobacco 287

lable harm, and it is at such times probably
that this pest of all (tobacco) pests starts its
campaign of mischief-making, which is estimated
to annually cost Manila only from $3,000 to
$6,500 (or £600 to £1,300) per factory for
cigars actually destroyed in the factory alone.’
For this reason I believe that it will be greatly
to the interest of tobacco planters in all parts
of the world to look into this matter of ferment-
ing and otherwise curing their tobacco, and to
see if it cannot be done in such a way as to
effectually prevent the beetle obtaining access
to the leaves. As the whole question of doing
so is of such paramount importance to the
success of the industry generally, I have
dragged the matter into this book in a way |
should not otherwise have done, simply because
I feel that if the beetle is to be kept away
from the tobacco at the start, new methods
will have to be introduced to supersede the
old ones, or if already introduced into some

1 « This,” Mr. Jones tells us elsewhere, ‘‘ represents

but a small fraction of the real loss, for these figures do
not include the shipment of infested cigars, which gives
a bad reputation to Manila cigars, and leads to a far
greater loss to the factory than does any occasional
. waste in goods or damage due directly to the beetle.
The Annual Report of the Bureau of Customs (Manila),
during the fiscal year 1911, shows a decrease in the
exportation to the United States, of tobacco and
tobacco products, from pesos 4,023,404, in Ig10, to
pesos 1,483,544 in 1911. (peso = Mexican dollar, or
about 2s.) The bulk of this decrease can undoubtedly
be attributed directly to the cigarette beetle.”

\

288 The Fermentation of Cacao

centres, that such improved methods must be
adopted elsewhere.

Mr. Jones himself includes an illustration
(see fig. 2) in his report showing how the
tobacco can be fermented in closed receptacles,
which, whilst keeping the beetle out, is said to
give equally satisfactory results as regards the

[Reproduced from the Philippine Journal of Science.”'|
Fic. 1.—Open mandalas (fermenting heaps) of tobacco.

quality of the tobacco as when the leaves: are
fermented in unprotected piles.

“The infestation of the tobaceo oy the
cigarette beetle,” he claims, ‘‘can be con-
trolled to a certain extent by the use of
modern fermenting compartment. This can
be so arranged as to prevent the beetles
entering freely, and it will give just as satis-

Curing and Fermenting Tobacco 289

factory results as the open mandala.” If, there-
fore, the root of the evil lies in the ability of the
pest to obtain access to the fermenting piles,
causing so much loss to the planters, I feel sure
the question of improved fermenting, or sweat-
ing compartments for tobacco, will also receive
the careful consideration of the planters and

Reproduced front the “ Philippine Journal of Science.” |
Fic. 2.—Closed Mandalas with Tobacco.

Government experts alike. ‘‘ Forty-one per
cent. of the annual factory loss due to insects,”
Mr. Jones tells. us, in his concluding remarks,
‘“‘would pay for the necessary chemicals and
labour to combat the pest, and 13 per
cent. for installing proper apparatus, There
would thus still be a saving of 46 per cent. on
this stock alone, and these figures do not take

1g

290 The Fermentation of Cacao

into account the direct loss due to this beetle
outside the factories or the indirect loss of
trade. At first the new and improved methods
must be carried on by persons who realize the
prime importance of accuracy and the necessity
for keeping treated stock free from reinfestation ;
but in the course of time, as work progresses
and the ordinary labourers become familiar
with the ordinary operations, the cost of
fermenting the tobacco by improved methods
may be greatly reduced.”

As regards drying and fermenting, reports
Mr. N. C. Chudhury, Travelling Inspector of
Agriculture for Behar and Orissa (India), the
plants, immediately after being conveyed to the
curing house, should be hung upon strings
6 in. apart, beneath the roof where it is well
ventilated. They should remain in this state
for about two months until thoroughly dry.
Early in the rainy season the plants must be
taken down, stripped and handled, when the
three qualities, best, medium and worst leaves,
should be separated, as they are stripped.
Sixteen to twenty leaves may be tied together
to make a bundle. These bundles are put into
large heaps, 2 to 4 ft. square, 4 to 6 ft. high;
and well pressed down for fermentation. A
beap should not contain less than twelve
maunds (maund = about 82 |b.) of dried leaves.
The leaves must be transferred in order to
avoid excessive heating, which can be ascer-
tained by touching the tobacco, and so testing

“Curing and Fermenting Tobacco 291

it by the hands, at one place and then another
in the heap, at intervals of, say, three or four
days until the desired colour and flavour is
obtained. Excessive heating spoils the colour .
and the flavour.

In Behar the plants are carried to some
grassy spot and laid out to catch the sun
during the day and the dew at night, being
turned daily. After a week or so, the plants
are stacked together. After three or four days’
heating the stack is broken and the plants are
laid out on the ground where they are kept for
two or three days. Then the plants are again
stacked for four or five days. This process of
heaping and spreading on the ground is repeated
six or seven times until the leaves and stems
are fully dried, when the curing is considered
over. The plants are then carried home when
the leaves are stripped and separated according
to their grades. The former method of curing
tobacco is recommended. i

Of late there has been some demand for
cigar and cigarette tobacco in India. It would
not be feasible for the ordinary Indian raiyats
to prepare these classes of tobacco. For the

‘growers of this tobacco, I may point out that
the cigarette tobacco should be. completely
dried very quickly, say within three days, for
which artificial -heat, gradually: rising from
80° to 170° F., in a specially constructed room
provided with ventilators, is necessary. A lower
grade of this tobacco may be dried in the sun.

292 The Fermentation of Cacao

For the manufacture of cigarettes light yellow-
coloured very thin leaves are wanted.

The process of fermentation: for producing
cigar tobacco is more difficult. Much care and
skill is necessary to bring this work to a
successful close. The desirable colour and
aroma of the leaves depend entirely on this
operation. After the leaves are dried in the
shed they are put into bulk. The leaves
should contain about 20 per cent. of moisture,
so should be artificially moistened with a fine
spray if too dry. On the other hand, 26 per
cent. of moisture in the leaf is considered
excessive. The temperature of the piles rises
to about 126° F. within two days. Leaves
should be rebulked in three or four days. The
bulk should be watched closely during the
fermentation. In the case of filler leaves the
temperature must not be allowed: to rise above
180° F, This maximum temperature is never
desired. A temperature of 160° F. for the
filler leaves and that of 120° F. for wrapper
leaves are recommended by the tobacco ex-
perts of the United States. When this tem-
perature is reached, the bulk should be broken
down and rebuilt. The bottom and top leaves
should now be placed in the middle. The
temperature now rises more slowly. The next
rebulking is necessary in seven or eight days.
Altogether the piles are repacked from five
to ten times until the temperature fails to rise.
The temperature of the fermentation room

“Curing and Fermenting Tobacco 293

should be maintained at 70° to 80° F. For
the wrapper, light brown-coloured leaves and
for the fillers deep brown-coloured leaves
of good aroma and burning quality are in
demand. The Sumatra variety of tobacco is
the best for wrapper and the Havana for the
filler. Among the country varieties, the Hingli
tobacco of Nadia, which has thin leaves of
mild flavour, may be suitable for ordinary «
cigarette tobacco. .
I have quoted these remarks at length
because I noticed that some little time back,
Mr. Bernard Coventry, Agricultural Adviser
to the Government of India, expressed the
opinion that the comparatively slow expansion
in the production of good tobacco in India was
mainly due to two causes, viz., the degeneracy
of the Indian plant, and the crude and primitive
methods employed in curing the leaves. From
what I know of Indian cigars, they are even
more liable to be “ pricked ” by insects (which I
take it is the same Laszoderma serricorne about
which Mr. Charles Jones writes so ably)
‘than Philippine cheroots or Cuban cigars. In
_the old days we have sent many a shipment
of Trichinopoly cigars to the West Indies,
with most unfortunate results, owing to their
perforated state when landed or soon after.
All this renders it extremely important to keep
the insects away from the tobacco as much as
possible, and above all when the leaves are
being fermented andcured. For these reasons,

294 The Fermentation of Cacao

therefore, I have included; these remarks in
order to call attention to the closed sweating or
fermenting chambers of the Philippine Isles, in
the hopes that by stimulating attention in that
direction, tobacco producers, the same as cacao
planters, will be encouraged to carry out
individual investigations, with a view of dis-
covering improved methods for fermenting
their leaves, not only to enable the enzymes to
improve the quality, but by keeping the beetles
and other pests away, to increase the output of
high-class tobacco from their estates.

295

INDEX.

Unless otherwise specified all processes, terms, &¢., in the
Sollowing Index only refer to Cacao and its preparation.

AcgTIC acid and alcohol, 24, 35, 41, 57, 62, 63, 8r, 82, 83, 92; 95,
100, IOI, 103, 106, 126, 141, 142, 143, 151, 182,
223, 231, 232, 233, 234, 236, 237, 238, 239, 242-
249, 253, 273, 275, 281, 282
& >» 9, fermentation, 231
> +> 99 its action, 182, 183
; >, in cacao, 237
ae »» producing bacteria, 242, 243
ether in cacao, 237
», fermentation and temperatures, 106, 107
Acidification with coffee, 129
Africa and washing cacao, 208
Agar tubes and cacao cultures, 240
Agricultural News (W.1.) on fermentation, 280, e¢ seg.
Air and the part it plays in oxidation, 68
», for drying, 270
», needed for fermentation, 140
», _ to cause change of colour, 149
Airing washed cacao, 209
Albumen in cacao, 237
Alcohol and acetic acid, 141, 151 (see also above)

a <5 »» in coffee fermentation, 62
5g 98 fermentation, 231
6 »» Vinegar, xxiv, xxxiv, I

1» becomes acetic acid ; due to bacteria, 143
»» for curing cacao well spoken of, 256
», from cacao, 219
x» in cacao, 237
>> yy) fermentation and its work, 41
1, its decomposition into acetic acid probably caused by bac-
teria, 143
transformed from sugar, 223, 253
Alcoholic acetic fermentation, 92

5 and the changes it produces, 83
Alkaline solution causes a lighter break in fermented cacao, 183
“3 », for acetic acid, 183

ie treatment (see Potash)

296 The Fermentation of Cacao

Amelonado cacao, 153, 156, 157
Analysis of cacao showing maximum, minimum, and average content,
231
ee »» Calabacillo cacao, 48
Aroma, I, 52, 55, 56, 57, IOI, 105, I17, 150, 257, 275, 276, 283
$i affected by enzymes, 58
>», and fermentation, 1
gi », its production, 276
is can never be obtained by fresh beans, 56
1, developed by low temperature, 203
33 discussion on the causes of, 150
#4 ae s» nature and origin of, 275
ey ‘a »» production of, 55
1 generation of the, 52
»» how to improve and how to spoil it, 117
1» increased by devitalization by cold, 257
Fe in tea, coffee, and cacao compared, 55
* not caused by fermentation, 55
», or flavour and slow drying, 281
»» _ the, is it caused by enzymes or roasting ? 52
Artificial drying apparatus, 194
Astringent flavour due to tannin, 49, 68, 85, 91, 237, 258
i substances ; their oxidation an essential point, 88
as taste and its reduction, the, 91
Aublet (1775), 29
o >» describes fermenting, 2
»» and fermenting, 13
Average air temperature, 183
»» humidity (St. Lucia, W.I.), 183

Bacillus aceté and cacao fly, 282

% subtilis comes after eight days’ fermentation, 282
Bacteria causes fermentation, 138, 139

‘6 harmful and otherwise, 24

a6 producing acetic acid, 242, 243
Bagging cacao, 215

», the cacao, cool before, 175
Bags for cacao must not be too light, 215
Bainbridge on oil of cacao, 280
Baker’s yeast described, 222
Balissier (see Heliconia bihaiz), 180
Banana leaves for covering fermenting cacao, 180
Barnard polisher described, the, 213, 214
‘Barrel of ‘‘ wet’ cacao, weight of, 170
Basket washing, 11
Baskets as used in Ceylon for cacao, 11

», for washing the beans in potash solution, 74

>> in cacao experimental work, 141
Beans (fresh) described, 15

>> killed at 45°, 151

Index 297

Beetles (Lastoderma serricorne) in exported cigars, 293
>» in tobacco, 286
5 rr) how to control them, 288, 289
55 ~ the cost of their damage, 287
Behar and Orissa (India), tobacco drying and fermenting in, 290
Bernard, Dr. C. L., of Java, on fermentation, 47
Bimbia Plantation, Cameroons, 7
Biological process the cause of fermentation, 138, 139
Bitter flavour being removed is of most importance, 273
55 » getting rid of the, 247
”» »» in cacao, I, 67, 68, 70, 85, 91, 105, 2375 238, 255, 256,
257, 258, 261, 268, 273
», principle in cacao, 237
>, taste and its reduction the prime object, 268
Bitterness and brown colouration, 258, 260
Blackman fans, 195
Boa Entrada (San Thomé) and fermentation, 100
5 Estate, S. Thomé, 93
53 » how it cures its coffee, 129
Pr experiments, criticisms on the, I1oI
Boiled or stewed beans, experiments with, 261, 262
Boiling prevents fermentation, 44
‘* Boucans,”’ 189, 190
Boxes for sweating cacao (see Fermenting boxes)
Brazil and washing cacao, 208 .
‘© Breaking bulk,” the same as ‘‘ changing cacao,” 181
“ Budding ” of yeasts, the, 222
Bulking cacao for shipment, 125
Bulletin of the Imperial Institute discusses fermentation methods, 258
Butter in cacao and its percentage, 230
Butyric acid through over-acidification, 84
By-products, vinegar, &c., 216, ef seq.

Cacao alcohol (see Alcohol)

s, and its chemistry, 230

3> 99g: efusal to ferment, 243, 244

a 3, tea fermentation, 99

ss 93,39, OXidation compared, 81

>, butter adulterated with coco-nut oil, &c., how to detect same,
283, 284

5 3 (see Fat)

»» (Calabacillo), analysis of, 48

4, changes which take place in, 238

33 crop, the world’s, xxxiii ;

5, curing, oxidation the chief object, 132

> : total cost of, 187

3, drying floors, 189

1» fermentation, 177

ne 53 compared with tobacco, &c., 130

298 The Fermentation of Cacao

Cacao fermentation, what does the term express? 82
+, fermenting floors and their advantages, 105
»» flies discussed and described, 226, 227
33 >» how they affect fermentation, 228, 229
x» floors and mildew, 190
o> fly, 159
sig »,, and Bactllus aceti, 282
a », at work, 180
is »» occurs in the Camercons, 271
»» fruit described by Loew, 39
», gather when ripe, 102, 103
»» higher temperature favours oxidation, 85, 87,' 89
», house roofs, 190
»» houses, an ideal plan discussed and illustrated, 174
»» how t6 prepare for tasting, 123
>, its entire preparation “discussed, 102, et seq.
o> 5) Preparation for market (by Fickendey), 66
2 jelly, 220
» liquid can be distilled, 5
>» measurenient and weight when curing, 121
» merchants and their profits, 163
» il (see also Oil and Oleum theabrome)
” 1 I51
» 99 and its melting point, 235
»» packing compared with tea, 125
. a, polishers and their use, 162
3» prices in 1911, 259
” » June I, 1913, 157
»» ready for shipment in thirty-six hours, 187
» red, 48, 49, 237, 263
>> 9) percentage in raw cacao, 48
»» Skin or sub-shell, formation of the, 16
» stealing, 158, 269, 270
>» sweatings, 249
», takes longer than coffee to ferment, 43
», vtasting, 122
», the drying of, 108
», thefts and the law in Cameroons and English Colonies, 269
», trays in San Thomé, 108
aU, tea preparation, 117
», vinegar (see Vinegar)
‘3 »» Spirit inflammable and of pleasant taste, 5
‘,, weighs heavy in fermenting boxes, 172
s» Why is it fermented? 138
x» yeast, and its small cost, 245, 246
- +» how to obtain it, 246
1» (see also Yeasts)
Cacaonine, 148, 151, 263
a and its formula, 149
Caffeine, 263

.

Index _ 299

Calabacillo cacao, 153, 156, 165
5 »» analysis, 48
45 >» Classified as unripe, 165
Cameroons against improvements in cacao curing, 266

ae and experiments with S. theobroma, 267
~ », vinegar making, the, 271 .

- »» Washing cacao, 107

= cacao fermentation in the, 78

ae Can drying floors oxidize sufficiently ? 118

a9 has the ‘cacao fly,” 271
ee vacuum dryers in the, 206
ais v. Ceylon and Samoa, the preparation of cacao in, 117
sie z. San Thomé fermenting methods, 104
sis weight of wet Forastero to dry, 270
Capacity of fermenting boxes, 172
Carbon dioxide associated with oxidation, (263
Castilloa latex, its effect on cacao-bean extract, 262
Catalyzers and enzymes, 67
ue the definition of, 67
Cement affected by liquid (vinegar), 107
»» floors for coffee, 128
»» for slate joints; 176
», (stone) floors in San Thomé, 113
»» floors, when used, 109
»» or stone floors, 85
>» _ % wood for fermenting floors, 107
Central America’s treatment of pulp, 42
Central America and washing cacao, 208
Ceylon and fermentation, 20
” », Samoa v. Cameroon cacao andits preparation in, 117
en 1» Washing cacao, 41, 57, 208
3», cacao gives S. theobrome, 267
>» fermenting fully described in, 10, 11
” ” in, 9
Changes which take place in cacao, 238
** Changing” fermenting cacao, 177
Changing raises the temperature, 181
93 the cacao, 181
Chemical changes in fermentation and the need of further research,
278, 279
Chemistry of cacao, the, 230
Chittenden and fermenting, 13, 14
3 method of fermenting, 12
on fermentation of the cotyledons, 23
ae on the generation of the aroma, 52
Chocolate of fine aroma needs the fat, 57 «y.
Chudhury, N. C. (India), on tobacco curing in India, 290, ef seg.
Cigar tobacco and its curing, 292
Cigarette tobacco and its curing, 291
# Clay and extra weight, 210

a”

300 The Fermentation of Cacao

Clay used on inferior cacaos, 210

Clayed cacao, 207, 209
9» Y. washing, 208

Claying cacao, why it is done, 209, 210

Coffee and cacao fermenting compared, 58
” 5s need enzymes when fermenting, 54
;, aroma compared with tea and cacao, 55
», and its fermentation, washing, drying and milling, 64
», compared with cacao, the fermentation of, 40
» curing, oxidation the chief object, 132
1» fermentation (by Loew), 58
5 38 beware of acid, 127

r ~ compared with tobacco, 130

” ” disadvantage of over-fermentation, 64
ag ‘i in Porto Rico, &c., 64

” 5 its benefits discussed, 65

” what it facilitates, 127

A fermenting and washing, 128 .

” 95 facilitates drying, 59
», fruits and their colour, 60
», how to prepare it for market, 60
" hulling and milling defined, 60
9 improved by immediate removal of pulp, 129
», in parchment best to ship, 65
», its anatomical structure explained and illustrated, 59
»» pulp (dry) analysed (by Greshoff), 61
+> 95) aS @ manure, 61
» shall it be shipped in parchment or not? 65
», takes less time than cacao to ferment, 43
», tastes flat when over-acidified, 129
», the fermentation of, 126
», under-oxidation causes harshness and bitterness, 129
», White spots on, 127
» Why it is fermented (by Loew), 59
55 (by Sir Geo. Watt), 58
Colour and ‘fermentation, 1
»» Change in cacao compared with tea, 46
»» in fermented beans, cause of, 44
»» in fresh v. boiled cut seeds, 44
» Of beans, 164
” a lightened with alkaline solutions, 183
» of ‘fine estate” and other cacaos, 194
of the seed, change of, 145
Colouration and reduction of bitter taste the prime object when curing
cacao, 267, 268
>» its production, 48
Colouring the bean follows its death, 45
Concrete tanks for vinegar, 219
” v. wooden fermenting boxes, 172
Cooling in oxidation, how to prevent, 119

Index

ies)
e)
=

Cool your cacao before bagging, 175
Copper sheeting for cacao floors, 191
»» _ wire for drying floors, 198
Cost of working artificial dryers, 196
Cotyledons, formation of cacao, 16
Coventry, Mr. Bernard (India), on the Indian tobacco industry, 293
Cracks a drawback in drying floors, 191
Criollo beans and washing, 208
5 x» are cured more easily than Forastero, 257
»» cacao, 154, 156, 166, 194
3) juice compared with Forastero, 253
» ¥. Forastero beans, their oxidation compared, 72
Crops and drying, two-fifths in fifty days, 191, 205
», come in unevenly throughout the year, 191
Cultures and their isolation, 241
», the isolation of pure, 241
Cured cacao, its ratio to uncured, 168, 169
Curing and drying cacao, loss in weight by, 169
3» cacao by alcohol well spoken of, 256
ae 1» total cost of, 187
»» of cacao by changes of temperature, 258, 259
a », _ the principal changes are in colouration and reduction
of the bitter flavour, 255
+» .or drying, and loss of weight, 186
,, tobacco in Behar, 291

“DANCING” cacao condemned, 212
i (see Polishing cacao)
Davies on oil of cacao, 280
Devitalization and drying, 257
5 by (1) heat; (2) cold, 257
Devitalized (by freezing) beans, experiments with, 262
Devitalizing temperature in cacao, 72
‘5 white v. blush-red beans, 263
Diseased pods, keep them apart, 166
“« Diseases” of wine and Pasteur, 222
Drain perfectly from fermenting boxes, 179
Dresel, Mr., 91
Drosophila melanogaster (cacao fly), 226, 227
Dry at the lowest temperature possible, 115
Dryer, Mr. Geo. Hudson describes his, 197, 198
Dryers, planters slow to adopt, 201
fi rotary hot-air, 199
;, sun-cum-artificial heat, 197
», the Gordon dryer described, 199
i >» Hamel-Smith, 200
- ;, Passburg vacuum dryer, 205
55 », Scott vacuum, 202
35 1, ‘ Whitfield-Smith ” described, 194-196
» vacuum, 201

302

The Fermentation of Cacao

\

Drying a crop, two-fifths in fifty days, 191, 205

”
”

and curing cacao, loss in weight by, 169, 186
» mildew, 193

avoid butyric acid formation above all, 115

by air, 270

(by Hudson), 186, 187

by sun v. mechanical means, 85

>, the sun, 264

cacao, do not leave heaps standing, 117

can the beans have too much sun? 193

facilitated by fermenting, 57

1§ per cent. moisture as a limit, 117

floor, space needed per 100 bags, I9I

house in San Thomé described, a, 112, 113
5 the Cameroons described, 111
3 Trinidad (W.I.), 111

houses—trays on wheels v. sliding roofs, 190
5, with sliding roofs, 189

in San Thomé, past methods of, 112

in vacuo, described, 202, 203

in wet weathers; how the heaping damages the cacao, 85, 87

maximum and usual heat, 198

may be too rapid, 85, 87

on ‘‘ boucans,”’ how it is done, 191, 192

or oxidation ; the question of the moisture content, 90

90 per cent. sun-dried, 187

" ‘slowly and its effect on oil and flavour, 281

>» the benefits of, 85, 87
the cacao, 108
5, disadvantages of rapid, 151
>, optimum temperature for, 73
>, temperature from the'sun less favourable to oxidation, 85
», test of thorough, 194
trays used in wet weather, 109

Economy effected in five directions whilst drying, 186
Eight tank or box system, 9
Enzyme and its effect, a proteolytic, 49

”
”
”

effects of killing the oxydizing, 45
what is an, 146
which splits glucosides, an, 263

Enzymes, 49

”
”
”

affect aroma, 58
and fermentation, 17, 44
», oxidation, 71, 78, 260
»» their production, 17
3, their work, 234
»» the part they play, 255
can be active in commercial (dry) cacao, 73
cause change of colouration in the beans, 146-148

Index 303

Enzymes cause fermentation, 67-70
ag destroyed at 70° C., 148

3s 93 by high temperatures, 264
os discussed by Fickendey, Preyer and Nicholls, 271
»», how the temperature affects them, 276
oP Li in cacao, how to prove their presence, 50
a5 in coffee fermentation, 63
55 in green and black tea, 46
“i in tea fermentation, 47
a in tobacco, 294
+3 93 curing, 286
46 killed by a synthetic fermenting juice, 54
5 must affect beans to get true aroma, 56

- necessary in coffee as in cacao fermentation, 54
5 (proteolytic) and oxidizing, 49 :
- the most essential part of the fermentation, 274
is what they are, and what they do, 67

Essential oil important for aroma, 55

Excessive temperature and its cure, 248

Experiments of beans, boiled or stewed, 261, 262

ES the need of estates to carry on further, 74
a5 a », further, 100
a to prove that it pays to ferment, 170

Experts in cacao centres, the need of, 116

Export of the beans, the, 124 .

External and internal fermentation, Dr. Fickendey on, 252
»» fermentation described, 143

Fans for drying, 60, 195, 198
as ri cost of turning, 198
59 as the most practical method, 271
», in the drying house, 264, 265

Fat (cacao butter) and its effect on the aroma, 56
6 33 »,» as digestible as cow’s butter, 56
y» percentage in raw cacao, 48

Ferment, Dr. Nicholls’ pure yeast, 160

33 is it necessary to? I
vs various. ways to, 2, ez seg.
Fermentation and how to start it, 276

ss and its causes, 17
- ;, changes chemically and in flavour, 49
sy > effect on colour, 43.
si >, two sections, IOI
56 and loss of weight, 186
a », the cacao fly, 228, 229
am », the changes it brings about, 253
0 », the moisture content, 92

” », yeast cells, 20
>, yeasts, 222 ,
‘3 an exact explanation of the nature of, 14

304 The Fermentation of Cacao

Fermentation boxes, 5, 7, 9, 29, 30
aft by change of temperature, 256
“98 aby chemical means, 256
»5 9 by Harrison, 35
95 by mechanical means, 256
3 caused by a biological process, 138, 139
5 causes physical changes, 234
Pe chemical combinations in, 24
or curtail rather than overdo the period, 118
se defined, 221
56 described by Hart, 34, 35°

5 6 Lucius Nicholls in detail, 231, 232
on ro Safford, 34

» a Sir George Watt, 34

” Wright, 32

Led
- details of chemical changes during, 282
ig discussed by Dr. Oscar Loew, 275
ay does it require air? 140
ais does not cause aroma, 55
5a experiments conducted in Germany, 89

» » » in San Thomé, 93, 95, 97

- falls into two sections, 92

i formula, 14

me how to hasten and improve, 226

ia 3, procure perfect, 244

is »» _ prolong, 245

4 in Europe, how imported beans can be utilized, 89
- in excess is wasteful, 248

Ee in tea, how to obtain uniformity of, 81

~ in tobacco, more rapid at high temperature, 286
55 is it biological or chemical ? 138, 139

5 is it profitable? 170

30 is not necessary, experiment to show how, 83
a its chief object, 57

av its effect on the beans, 23

ao liquor, Dr. Fickendey’s analysis, 253

ve » Specific gravity of, 253

59 losses and gains due to, 235

a loss in weight by, 169

% methods discussed, 29

‘8 need to continue investigations, 186

7 of cacao, what does the term express ? 82
” of coffee, the, 126

ae of secondary importance, 273

35 of tobacco, the, 130

a one hundred and forty years ago, 134
period, 137

ay process has not changed, 136

a results of good and bad, 25, 28

= », if wrongly conducted, 254

Index 305

Fermentation, summary of the process, 57

temperatures, a table of, 184
the activity of bacteria in, 24
1» Chief purposes of, 40
»» Native methods, 103
- oxidation of astringent substances an essential point, 88
»» rise in temperature, 39
trials, tables of results, 26, 27
when it is most active, 230
when it will not take place, 244
why preferable to merely sundrying, 43

3”
Fermenting according to Semler, 30

as »» Chittenden, 12
a minor expense compared to curing, 187
and malting floors, 107
a potash bath, then dry, 73
boxes, 121, 162
»» and “cacao fly,” 159, 271
» 95 Sheds in Surinam, 136
» » their scrapings, 225
», the weight of their contents, 172
+» capacity per 300 Ib. wet cacao, 172
», discussed, 171-176
»> (Dr. Schulte’s), 95
»» how to construct them, 171
a5 »» make them, 172, 173
x» must drain perfectly, 179
number necessary for a 300 bag estate, 171
», Of slate, 175, 176
or receptacles, various, 7
s, Strickland’s principle, 5
cacao, 177
its chief aim (Fickendey), 67
+» Uncover to allow access to the ‘‘ cacao fly,”’ 180
», v. malting barley, 49
chambers for tobacco, 288, 289
described by E. Friederici, 7
59 by Semler, 6
floors, 7, 10, 37, 85, 105, 107, 109, I11, 120, 136
3, (see also Floors)
in cacao, causes of, 225, 226
in Ceylon, 9
(in 1775), by Aublet, 2

a

”

" in Surinam (Preuss), 9

20

in Venezuela, 5
in wooden troughs for small quantities, 107
juice, a synthetic and its result, 54
», at present a waste, 249
liquors differ in quality, 253
not always easy to start, 225

306 The Fermentation of Cacao

Fermenting on Gangaroowa Estate (Ceylon), 10
55 -process fully described, 178

* receptacles, 171
58 smaller lots take longest, 183
9 the question of acidification, 105

2 >, minimum temperature, 177
‘i s, most important process according to Preyer and
Nicholls, 274
ey 5, Strickland process, 5
3 with yeast cultures, 245
Ferments for vinegar, 218
53 in tobacco curing, too much importance attached to, 130
Fibrin in cacao, 237
Fickendey and Schulte im Hofe seem to agree, 272
5 discusses Dr. Axel Preyer’s essay, 267
55 doubts the advantages of using yeasts, 254
on using potash, 274
Fickendey’ s (Dr.) essay, 66
“last word,” 252
sf Finings ” for vinegar, 218
Flat beans, 164
Flavour increased by devitalization by cold, 257
Floor for fermenting, the best, 105
Floors and mildew, 190, 191
3, can they induce sufficient oxidation ? 118
>, cement and otherwise, 189
>» for fermenting, avoid cement and lime, 107
», for polishing, 211
3, of cement for coffee, 128
1 99 99 or stone, 85
3» 99 99 When used, 109
+» 93 metal for drying, 120
», Stone or cement in San Thomé, 112, 113
», v. Sugar-pans for dancing, 211
working the cacao on, 193
Forastero and Criollo beans compared and discussed re curing, 263, 264
>» beans and their proportionate weight wet and dry, 270
ne » less easy to cure than Criollo, 257
33 cacao, 154, 156
ae v. Criollo beans, their oxidation compared, 72
Formula of fermentation changes, 14
a of the change of alcohol to acetic acid, 143
Friederici, E., and fermenting, 7, 13

Ganearoowa EstaTE (Ceylon) and fermenting, 10
Garrett floors for drying, 161

Germs (in beans) killed by freezing, 68

Gillespie’s (Barnard) polisher described, 213, 214
Glucose in cacao, 236

Glucosides and oxidation, 263

Index 307

Glucosides, defined, 148

a and their splitting, 263
Gluten in cacao, 237
Gordon dryer described, the, 199
Gordon’s (Malins-Smith) polisher, 213
Government Agricultural Department should distribute S. Theo., 185

¥ help planters? should the, 160
Governments to test estate machinery, 207
Grenada cacao, the improvement in, 154
Gruess, J., 261, 262

»» method of reaction, the, 261

Guam, fermentation in, 34
Guardiola dryer in the Cameroons, the, 112
Guatemala and coffee fermentation, 64

HAMEL-SMITH dryer, the, 200

Hammerschlag, J., of Strassburg, 132

Harper, J. N. (U.S.A.), on tobacco-curing houses, 285
Harrison, Professor, on cacao-sweatings’ contents, 231

a9 56 » colouration, 48
58) 5 is fermentation, 35
” ” 1, reducing astringent flavour, 49

» tannin decrease, 53

” Led
Hart, J. Hinchley, 2
», discusses the aroma, 55
», on colouration, 48
»> 1) fermentation, 18, 34, 35
1» 92 partly fermented cacao, 54
1» 5) the generation of the aroma, 52
s, v. Loew and Schulte ve fermentation, 37
Heaps, fermenting in, 10, 12
»» When drying must not be left standing, 117
Heat with fermentation ; is it necessary ? 40
Heliconia bihai (wild plantain) leaves for fermenting cacao, 180
Hildebrand and Son, Theodor, 89, 91 °
Hilger and cacaonine, 149
Hilger and Lazarus, 150
Hot air drying and trays, 264
How to construct fermenting boxes, 172, 173
Hudson’s, Mr. Geo. S., dryer described, 197
$5 3 essay, 153

INADEQUATE fermentation and its cause, 180
India tobacco, drying and fermenting in, 290
3, too primitive in its curing of tobacco, 293

Indigo and its shipment, 124, 125

>> 99 tea fermentation compared, 77

x» fermentation compared with tobacco, 130

»» (Lndigofera tinctoria) fermentation, 77

»» | preparation—oxidation the chief object, 132

308 The Fermentation of Cacao

Inoculation method of fermentation, 156
Internal fermentation, 151
sy ss and its processes, 144
i limited in effect, 247
Investigations re ferments should be continued, 186
Iron stains cacao, 182

JONES, Soe R. (Philippines), on tobacco fermenting and beetles,
286, 287
Juice (cacao pulp) described, 5
», from the sweating box runs to waste, 249
3, or liquid affects cement floors, 107
»» Or vinegar and its escape, the, 37, 136
oe +8 its disposal, 11
5 a5 should it remain or be drained off ? 28
»» worth 3d. per gallon for alcohol, 220

KAISERLICHE Tabak-Manufaktur, Strassburg, 132
Katayama on aroma in tea, 55
Kriegsschiffhafen Plantation, Cameroons, and its drying shed, 111

Lasioderma serricorne ox tobacco beetle, 286
5 A how to control it, 288, 289
in exported cigars, 293
Lange, Eugene, says washing does not pay, 42
Lazarus, 150
», on glucosides, 263
Leaf covers aid fermentation, 180
Leaves for covering fermenting cacao, 180
Lime wash to counteract acetic acid, 183
Liquid or juice affects cement floors, 107
Loew compares Hart and Schulte with himself, 37
Loew, Dr. Oscar, on the fermenting of cacao, 275
Loew’s essay, Dr. Oscar, 32
», ‘last word,” Dr. Oscar, 275
Loss in weight through curing, 169
Loss through washing, 208
Losses and gains due to fermentation, 235
Low-class cacao—is it wanted ? 160

MACHINE polishers and their capacity, 212, e¢ seg.

+ we described, 212, ef seg.

oe x3 Gillespie’s ‘‘ Barnard,” 213,214

»» Gordon’s “ Malins- Smith, ” 212, 213

Machines for estate work, why the Governments should test, 207
Malins-Smith polisher described, the, 212, 213
Mandalas (or tobacco- fermenting heaps) and beetles, 286
Mann, Dr. Harold, and tea fermentation, 47
Mayfarth dryers, 84, 85

>» dryer in the Cameroons, the, 112

. Index 309 ©

Measurements of cacao pods, beans, &c., 39
Measuring ‘‘ wet’ cacao, 166
Mechanical dryers, what to avoid in, 112
Mechanically treated coffee, avoid heating with, 128
Mediums for the cultivation of organisms, 239
Mendonca, Mr. Monteiro de, 93
Mildew and sulphate of copper, 191
»» decreased on clean heans, 208, 209
>» in fermenting boxes, 175, 179
»» on cacao floor should be removed, 190
>, When drying, 193
Moisture and fermentation, 92
we s» moulds, 91
- s» Oxidation, 118
” content, 90
»» how to estimate the degree of, 118, 119
” in ¢acao, 90, 95, 97, 117, 118
- 3» drying, limit, 15 per cent., 117
as », in export tobacco = II per cent., 286
Molasses assist fermentation, 142
Monte Coffee Plantation, San Thomé, the, 114
Montet, Maurice, on Schulte’s apparatus, 38
Morris, Sir Daniel, describes superior cacao, 24, 25
+3 3 and fermenting, 13
Moulds and moisture, 91

NEGATIVE experiments, 182
Nicholls, Dr. Lucius, and his ferment, 160, 177

xe me oe discusses the other essayists, 276, 277

ae iy ae the discoverer of the use of the ‘‘ cacao fly,” 271

ais and Preyer consider fermenting of most importance, 274

8 ss 93 ve use of yeast, 271

ie ferment, or S. ¢heobroma, and its effect on the beans, 185

me 1 (S. theobrome) should be distributed by Govern-
ment, 185

ss s» and temperatures, 184

es on yeast and fermentation, 271, 272, 273
Nicholls’ ‘‘ last word,” Dr. Lucius, 277

OIL (cacao) and dancing, 235
5s E. 3, polishing, 210, 211
+s »» how to obtain it, 150, 280, 281
,», (fats) diffused at 110° F. and above, 248
Oil of cacao, the essential, 280, e¢ seg.
Oleum theobrome, 236
8 sf 280, ef seq.
‘6 - and its melting point, 235
ay a 24 c.c. in 2,000 kos. of beans, 283
Optimum temperature for sweating, 248
Organisms and their three stages, 242

310 The Fermentation of Cacao

Organisms which ferment cacao, their isolation and cultivation, 238
Over-acidification avoided by trays, 87
Over-curing cacao, 194
Over-oxidation in coffee spoils it, 129
Over-ripeness and its effect on the beans, 45
Oxidase and peroxidase, 51
»» in white and bluish-red beans, 263
», the definition of an, 70
Oxidases, the part they play in fermentation, 70
$e and the preparation of cacao, 261
ee assist the colouration, 72
sts can be killed by boiling or acids, 44
» killing temperature of, 44
Oxidation and enzymes, 78

4 »» moisture, 118, 119

55 » tannin, 68, 69, 70, 71

a »» the necessity of acid, 92

os associated with giving off of carbon dioxide, 263

a by heat, 71

4s capacity per 500 kos. of cacao, 121

33 chambers in San Thomé, 93

59 curtail rather than overdo the period, 118

a8 effect of the air in, 68

95 favoured by higher temperature, 85, 87, 89

a5 <a s, slow drying, 88

7 house, Dr. Schulte describes his special, 120

- how to accelerate, 274

” s» shorten the period of, 133

ie in cacao and tea can be produced by chemical means, 83

ee », tea; how it is facilitated, 80

si of cacao, the, 115

sa i (by Schulte), 115, e¢ seg.

x or colouring indirectly due to fermentation, 43

5 3, Grying ; the question of moisture content, 90

$6 proceed cautiously, 116

$35 the question of irregularity in, 99

33 », unfavourable reactions, 84
when it proceeds quickly, 72 .

”
Oxygen and its part in tobacco fermentation, 130

PACKING tea compared to cacao, 125
Palette, the, 192
Para and its cacao wine, 219
Parchment coffee, 60
FY} in coffee and its disposal, 127, 128
Passburg vacuum dryer, the, 205
Pasteur and ferments, 221
Peasant proprietors and their cacao, 244
Penicillium glaucum, 14, 17
Pentagona cacao, 154, 156, 166, 194

Index 311

Peroxidase and oxidase, 51
Persimmon compared with cacao, the curing of, 47, 49
Petri plates for cacao cultures, 239
Physical changes due to fermentation, 234
Picking unripe pods, 164
Placenta and its removal, the, 165
Pods, how they are gathered, broken and disposed of, 10
», picking unripe, 164
Polished cacao, 207
Polishing and cacao oil, 210, 211
es and sun-drying, 212
», by dancing condemned, 212
»» by machines described, 212, ef seg.
95 cost per cwt., 211
»» described in detail, 210, ef seg.
»» how it affects the bean, 211, 212
»» in sugar pans (tayche), 211
a machines, cost of an installation, 214
3a must not be done too soon, 210
»» Or cacao-dancing and its effect on the oil content, 235
- v. washing, 208
»»_ whilst vacuum drying, 204
Porto Rico and coffee fermentation, 64
¢ »» as S, ellipsoideus and S. apiculatus, 276
‘5 »» Chocolate, how it is made, 57
Potash after fermenting, proposed use of, 73 (see also p. xxxvi)
»» and its use in cacao curing, 274
», bath, how to give the beans a, 74
fr »» the advantages of, 73
Practical estate cacao curing, 164
‘Preuss and fermenting, 13
»» describes fermenting in Surinam, 9
»» on loss by washing, 152
Preyer and fermenting, 13
>», and Nicholls consider fermenting of most importance, 274
35 Pe ve use of yeast, 271
>> Dr. Axel, and his ‘‘ last word,” 277
Preyer’s essay, Dr. Axel, 1
Price for washed and unwashed cacao, 208
Prices not in proportion to quality, 265
», Of cacao in IQII, 259
” ” June, 1913, 157
» Of well-cured v. other cacaos, 153, 155
Profits from well-fermented cacao, 160, 161, 162
Pulp (see a/so Cacao pulp, Coffee pulp, &c.)
», and its loosening is not important, 267
+» and washing, 1
+» (cacao) and its removal, 40
#% »» and what it consists of, 15
3, disappears with fermentation, 151

312 The Ferntentation of Cacao

Pulp, how affected by the generated alcohol, 41

», in Central America is dried on, 42

3 its immediate removal improves coffee, 129

3» more easily removed in fermented beans, 19

+, O¥ juice and its contents, 253

5 », heed not be separated from the beans, 255

or slime cells, how they are destroyed or got rid of, 41

Pulped coffee, 60
Pulping coffee explained, 61

QUALITY of commercial cacao, who is to decide it? 247

RAINFALL to be considered when drying, 188
Rapid drying and its disadvantages, 151
Ratio of uncured to cured cacao, 168, 169
Ridging beans to hasten drying, 192
River pollution with cacao juice, 173
Roasting beans and colouration, 45
Roofs for drying houses, 190
Rotary dryers, 165
»» drying machines in the West Indies, 187
»» hot-air dryers, 199
Rubber in Malaya, vacuum dryers for, 206
‘* Ruberoid’”’ for cacao houses, 173, 176

Saccharomyces apiculatus, 41

4K 33 and S. el/ipsotdeus in Porto Rico, 276

3 - in coffee, 62

44 cerevisia, 14

39 ellipsoideus, 20, 41

5 +3 v. S. theobrome, 276

a in coffee, 61 ;

ie membranafaciens, 20

xa theobrome, 225

a9 $3) and its use as a ferment, 254

45 ae », temperatures, 184

9 i described, 20

i a3 discussed, 243

3 $5 fermentation, does it pay? 157, 158

Me x3 found on Ceylon cacao, 267

5 5 should be distributed by the Government
Agricultural Department, 185, 186

35 #9 the best ferment, 24, 273

used in the Cameroons, 267
Saccharomyece apiculatus, 282
anomalus, 282
Sack’s essay, Dr. J., 134
Safford on fermentation in Guam, 34
+ 9, generating the aroma, 55
Sale and shipping charges on cacao, 215

Index 4rg
,

Salt to kill maggots on cacao, 134
Salts in cacao, 237
Salzmann, of Berlin, Dr. H., 89
Samoa and Ceylon v. Cameroon cacao and its preparation, 117
” »» washed cacao, 208
» _ cacao, how it can be spoilt, 117
Samples for selling, 125
San Thomé and coffee fermentation, 126
39 i +, its peculiar method of coffee fermentation, 128
3 » Dr. Schulte’s test for cacao tasting in, 123
rr » early drying systems, 112
33 »» tries stone floors for drying, 113
8 »» v. Cameroons fermenting methods, 104
Schulte im Hofe’s apparatus discussed by Loew, 37
” ” essay, Dr., 76
aH i “last word,’ 272
Schulte im Hofe tends to agree with Dr. Fickendey, 272
a yi v. Hart and Loew ve fermentation, 37
9 ” v. Spengler tunnel dryer compared, the, 114
Schweitzer and his glucoside-splitting enzyme, 263
Scientific supervision, the need of, 116
Scope of suggested improvements, 153
Seed killed at 40° to 45° C., 43
»» selection, 156
Seeds die at 40° to 45° C., 45
Semler and fermenting, 13
»» describes fermenting, 6
Semler’s method of fermenting, 30
Separation of the different qualities, 166
Shell (cacao), the formation of the, 16
Shipping and sale charges on cacao, 215
Signs of a well-fermented bean, 235
Slate fermenting boxes, 175, 176
59 33 »,» . cleaner and more free from insects, 175
Slime layer in coffee, the cause of its separation, 63
13 (see Pulp)
Sloe (Prunus spinosa) compared with cacao, 260
iy 3 its oxidation compared to that of cacao, 70
Small cacao proprietors, 159
Smears of cacao-sweating pulp described, 224
Spengler v. Schulte tunnel dryer, the, 114
Standardization calls for similarity in preparation, 280
Standardizing cacao for shipment, 125
Starch in cacao, 236
Stone platforms for drying, San Thomé, 113
Strickland and fermenting, 13, 14
a3 process of fermenting, the, 5
Sucrose in cacao, 236
Sugar, does it cause the rise in temperature ? 141

3, and water give alcohol and carbonic acid gas, 143

314 The Fermentation of Cacao

Sugar (dextrose and leevulose) in the pulp, 253
» its decomposition into alcohol probably due to a fungus, 143
», transformed into alcohol by zymase, 223
3, vessels to improve aroma and taste of the cacao, 135
Sulphate of copper for mildew, 191
Sun was formerly considered injurious to cacao, the, 135
Sun-drying and its effect on colour of beans, 43
a3 and polishing, 212
a but not fermenting, the effect of, 42
m discussed, 188, 264
e is the best, 270
6 when it cannot be disregarded, 189
Superior cacao described by Morris, 24, 25
Surinam and cacao planting in the past, 134
ah fermenting in, 9
x» loss by washing in, 152
Sweating (see Fermenting)
Sweatings or fermenting fluid from cacao, 249

TABLE of cacao values (1911), 157, 259
», Of fermentation temperatures, a, 184

Tania leaves for covering fermenting. cacao, 180
Tanks for vinegar, 219
Tank-system for fermentation, table showing, 13

x» _ (see Fermenting boxes)
Tannic substances in cacao, 70, 72, 260, 261,
Tannin, 44, 46, 47, 48, 49, 53, 58, 68, 260, 261, 262, 263, 264

»» and its effect on the aroma, 53

an », OXidases, 70 -
A », oxidation, 68, 69, 71
35 », taste of beans, 58

», discussed, 49

»» increases bitterness, 49

»» in tea, 46

percentage in raw cacao, 48

Tannins (cacao) discussed, 44, 46, 48
Taste in fermented v. roasted beans, 50
Taste ? what causes the, 150
Tasting the cacao, 122
Tea and cacao fermentation, 99

is i oxidation compared, 81

3, and its change of colour compared with cacao, 46
za »» preparation for market, 80, 81

¥y », tannin content, 46

») aroma compared with coffee and cacao, 55

se », its generation explained by Katayama, 55

», curing, oxidation the chief object, 132

3» enzymes in green and black, 46, 76

1», fermentation compared with cacao, tobacco, &c., 130
55 +3 the need of new methods, 46

Index 315

Tea (green and black) fermentation, 46, 78
»» higher temperature favours oxidation, 87
»» how to prepare for tasting, 123
»» lack of uniformity when curing, 99
»» packing compared to cacao, 125
3, v. Cacao preparation, 117
» why it is rolled, 80
Temperature, 48-49

”

and its effect on enzymes, 146
(45°) at which beans are killed, 151
at which seeds die, 45

»» yeasts are most active, 248
average air, 183
cure for excessive, 248
dry at lowest, 115
during fermentation, rapid rise in, 39
fatal to yeasts, 248
for cigar tobacco curing, 126° to 180° F., 292
from sun may be too low for favourable oxidation, 85
in basket experiments, 142
», coffee fermentation, 62, 63
y) excess spoils colour and flavour of tobacco leaves, 291
», fermentation, the question of, 92
», fermenting, 37, 73-177
», internal fermentation, 144
», oxidation house, 121
3, San Thomé (for fermenting), 97
,, tobacco kill enzymes above 152° F., 286
ay vacuum dryers, 202
is'the rise due to conversion of sugar content ? 141
lowered by not changing the cacao, 181

ie ys, removing leaves when fermenting, 180
necessary to kill the seed, 43
of oxidation, the optimum, 100
rises as alcohol becomes acetic acid, 143
the cause of its increase, 41
the higher it is the better the cacao, 275-276
100° the minimum for fermenting, 177, 179
the optimum for drying, 73
the question of, 248
what causes the rise in, 141
when fermenting coffee, 127

a higher favours oxidation, 85, 87, 89
»» low improves aroma, 203

Temperatures and acetic fermentation, 106, 107

»» results, 25

,», their effects on cacao, 258, 259
at various times of fermentation, 281
changed to cure cacao, 256
discussed, 25, 28, 37, 39, 43

316 The Fermentation of Cacao

Temperatures in oxidation, how to retain them, 119

3% maximum and usual, 198
4 when curing tobacco, 131
53 with Nicholls’ ferment v. ordinary ones, 184

»» ordinary fermenting methods, 183
- Testa and its colour, 42
s» of fermented and unfermented beans, 42

Testing cured cacao by tasting, 98
Theine, 237
Theobroma guianensis, z
Theobromine, 151-263

55 composition of, 149

” in cacao, 237

its origin, 150

Three tank or box system, 8, 9, 10
Tobacco curing experiments, 131

ee »» fermentation only secondary, 132
5 1 for cigars, 292

a »» houses discussed, 285, 286

55 »» Oxidation the chief object, 132

», drying and fermenting in India, 290
», fermentation compared with tea, indigo, cacao and coffee, 130

33 ” more rapid at higher temperatures, 286
:» for cigarettes must be dried quickly by artificial heat at 80° to“
170° F., 291

se how to ferment, 130, 131
», industry in India is too primitive, 293
»» hotes on the curing and fermenting of, 285
», the fermentation of, 130
when to stop fermentation, 131
Trays and fans the most practical method, 271
» drying with, 264
»» for drying, 195, ed seg.
ae eee their measurement, 198
», in Cameroon, drying-houses, 111
», 2. floor for drying, 190
Trinidad (W.I.) and claying, 209
as drying-house described, a, 111, 189
Trolleys for drying, 97
Tunnel drying, 95, 113, I14, 121
9 »> in Fernando Po described, 113

UNCURED cacao, its ratio to cured, 168, 169
‘* Unripe”’ beans only partially fermented, 104
i beans? what are, 164, 165
Unwashed and washed cacao, difference in price, 208

VACUUM dryers, 165, 201
5 », and their advantages, 203
” ” »» charge, 205 :

Index aby

Vacuum dryers, rotary v. rectangular chambers, 204

»» the cost of, 205, 206
drying, 187

>, and its advantages, 162

»» described, 202, 203

3, polishing whilst, 204

Venezuela and claying, 209

”

fermenting in, 5

Victoria Gardens (Cameroons), Botanical Gardens, 78
Vinegar, 28, 216, ez seq.

”

and alcohol (see Preface, pp. xxiv, xxxiv)
» ‘‘finings,” 218
(cacao) compared to others, 250
from cacao can be of good quality, 216, 217
ne ys juice, how to make, 249
», the pulp, 41
if replaced, does not help fermentation, 182
keep clean, and bottle attractively, 217
making in the Cameroons, 271
** mother,” the, 217
or cacao fluid, and its disposal, 173
or juice, 11
selling price of, 216
should be syphoned and filtered, 218
should pay to produce, 251
tanks, 21¢
the question of ferments, 218
what it means to the planter, 216
200 gals. per 100 bags cacao, 216

WASHED and unwashed cacao, difference in price, 208

”
2”

cacao and airing, 209
coffee, 60

Washing and fermenting coffee, 128

”

cacao, 2, 9, II, 207
5, and the loss occasioned, 264
” o> 9» pulp, I, 2
33 3, what it saves buyers, 207
>» in Ceylon, 34, 41

,, the Cameroons, 107, 108
3» the loss discussed, 152
3» where it is in vogue, 208

facilitated by fermentation, 19

in Ceylon, 57

its loss to planters, 208

said not to pay, 42

the advantages of, 42

Water for polishing, beware of over-supply, 211

29

used when polishing, 211

Watt, Sir George, describes fermentation, 34

318 The Fermentation of Cacao

“ Weathering,” 161
Weight, loss during curing, 186
», Of fresh v. cured cacao, 270

Weights of bags of cacao, San Thomé, Trinidad, Grenada, 215

Well-fermented beans, how to tell, 194

West Africa, vacuum dryers in, 206

West African cacao and its preparation, 258

West Indian cacao and washing, 208

‘* Wet” cacao and its measurement, 166

Where improvements may be effected, 186

White-nibbed beans and their behaviour, 263

White spots on coffee, 127, 129

‘« Whitfield Smith ” dryer described, the, 194

**Wild’’ yeasts, 244

Willis, Dr. J. C., 2

Wood v. cement for fermenting floors, 107

Wooden spades for fermenting cacao beans, 182
v. concrete fermenting boxes, 172

World’s cacao crop, the (xxxiil)

Wright, Herbert, on fermentation, 32

YEAsT cells and fermentation, 20
a9 », turn to alcohol and then to acetic acid, 41-57
» colonies discussed, 243
» cultures and their influence on the beans, 106
9 » for fermenting, 245
£5 1 give a better cacao, 245
6% » Of merely theoretical interest, 106
», for cacao and its small cost, 245, 246
1, to ferment cacao, how to obtain it, 246
Yeasts and fermentation, 222,
i », their optimum temperature, 248
1 93. 93_«~Feproduction, 222, 223
“4 +» 9) uses should be carefully studied, 279
» ‘do they vary in different centres? 279
» Fickendey casts doubts as to their advantages, 254
» killed at 133° F., 248
»» more than one colony work at a time, 181
+. ON cacao, 17

ZIPPERER and cacao, red, 237
as on changes during curing, 49
Zymase and its presence, 233
», transforms sugar into alcohol, 223

Joun Bate, Sons anp Danimisson, Ltp., Great Titchfield Street, London, W.

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Phosphoric Acid,

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dry and in moist granular form, best means for defecating
Sugar Cane Juice.

For Prices and Particulars apply to:

CHEMICAL WORKS, late H. & E. ALBERT,
London Agency—15, PHILPOT LANE, LONDON, E.C.

SOLE Export AGENTS .FOR THE
Société Anonyme des Engrais Concentrés Engis.

Advertisements

The Production and Preparation of
Cacao, Coffee, Tea, &c., for Export.

This volume informs you how to prepare your
produce for shipment.

You must first obtain your produce, and this can
only be done properly by judicious fertilising.

The secret of successful fertilising is a proper use
of NITROGEN in the best and most available form.

NITRATE OF _SODA

fulfils these requirements, and in combination with
phosphates and potash forms an ideal fertiliser.

ALL INFORMATION as to its USE, EFFECT ON CROPS, &c., may
be obtained gratis and Post Free from the following offices of the Chilean
Nitrate Propaganda :—

For Australasia—Mr. Aurrep E. Steruen, G.P.O. Box, 1197, Sydney, N.S.W.

Cuba—Mr. H. O. NeEviLLe, Comité del Nitrato de Chile, Lonja del Comercio
517, Havana.

Egypt—M. Victor M. Mosserr, 25, Cheick Abou-el-Sebaa, Cairo.

Japan and Philippine Islands—Mr. Joun StruTHERS, M.A., B.Sc.,
No. 6, Babasaki, Kojimachi Ku, Tokio.

Mexico—Mr. Runar O1sson-SEFFER, Comité del Nitrato de Chile, Av. San
Francisco No. 1, Mexico, D.F.

U.S.A., West Indies, Hawaii—Dr. W. S. Myers, 25, Madison ‘Avenue,
New York.
OR FROM—

THE CHILEAN NITRATE COMMITTEE,

Friars House, New Broad Street, London, E.C.

Advertisements

CROSS'’S
Celebrated Fertilizers

Specially Prepared for thé Cultivation of

CACAO, ::

COFFEE, SUGAR CANE,
TOBACCO, TEA, RUBBER,

&e., &e.

SUPPLIERS OF ALL KINDS OF FERTILIZERS.

SULPHATE OF AMMONIA PHosPHorRic AcID
NITRATE OF SODA Sotip PHospHoric AcID
NITRATE OF LIME DousLE SUPERPHOSPHATES
PHOSPHATE OF AMMONIA SUPERPHOSPHATES
PHosPHATE OF POTASH Basic SLAG, &c., &c.

ALEXANDER CROSS & SONS, Ltd.

(Established about 100 years),

Largest Chemical Manure Manufacturers in Scotland.

qd

Registered Office ses i caw | 19: Hope Street, Glasgow.
Branch Office an .... Fenwick Chambers, Liverpool.

Chemical & Fertilizer Works ... ‘1. Port’ Dundas, near Glasgow.
eth ets Camelon, near Soamigemauth,

Basic. Slag Works

vm Seutis. Bank, "Nisddlatbrough, ;
... Sydney, Cape Breton, Canada.

”

22

al iverlisements

Woven Wire-Work
Flooring and Shelving

(SUPPLIED FOR ALL MARKETS)

ALL MESHES AND STRENGTHS,
HEAVILY GALVANIZED AND
RUST-PROOF.

For drying produce as described in this book, °
in ‘‘Coco-nuts, the Consols of the East,”
‘Tropical Life,” ‘“Grenier’s Rubber News,”
| and in other publications.

Acid Resisting Cloths of German Silver or
Pure Nickel Wire, Aluminium Gauze.

Fine Wire Gauze in Brass, Copper, Phos-
phor Bronze or Nickel, up to 300 holes
per lineal inch =90,000 holes per square inch.

GEORGE CHRISTIE, Ltd.,

Ladywell Wire Works,
GOVAN, GLASGOW, SCOTLAND.

Advertisements

Wire Gauze
Mosquito Netting.

BRASS—COPPER—GALVANIZED.

Christie’s Oxidized Phosphor Bronze
Mosquito Netting is the most durable and

economical to keep away Mosquitos from man,
as at Panama, the West Indies, &c.; Flies
from Horses, and the Tobacco Beetle from the
heaps of Fermenting Tobacco (see pp. 285 to
294 in this book) as in the Philippine Islands ;

and for many similar purposes.

Use screens made of our wire, and you will
enjoy better health, and save much money,
both in doctors’ bills and in a larger output

of improved quality of produce.

GEORGE CHRISTIE, Ltd.,

Ladywell Wire Works,
GOVAN, GLASGOW, SCOTLAND.

Advertisements

Ransomes Disc Ploughs

ARE THE BEST
FOR THE TROPICS.

They penetrate hard, sun-baked land,
thoroughly pulverize the soil,
and bury all weeds.

Ransomes also supply various other Ploughs

specially designed for ‘Tropical Agriculture.

Ridging Ploughs, Ploughs for making trenches

for sugar-cane slips, very light Ploughs for native
use, &c.

CATALOGUES GRATIS ON APPLICATION.

RANSOMES, SIMS & JEFFERIES, Lo.

IPSWICH, ENGLAND.

AALVETLISETHENES

SSOUPPY “191 S3NOHd3713.L

“Sounasve’ | ‘SU10H 40 3ZIS ONY S3HSIW ‘STVI3W TIV NI]...

“GNV ISNA

‘NOLONTHUW A

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hey SNOS Z ONINGIYD 'N AS

SuayVW ta. i a4 “a

» = “S.LAIHS
03.1Vd0ddad

anv

UNINIAUIS
JdIM

"SSILIVVIOSdS

"S139HS OILVYOIUTd ‘IYI NIAOM ‘SNINTIYIS FIM ‘HLOTS JYIM

Advertisements

WEST & SOUTH-WEST COASTS OF AFRICA,
THE CANARY ISLANDS, AND MADEIRA.

The Steamers of

The African Steam Ship Company

((ncorporated 1852 by Royal Charter) ; and

The British and African Steam
‘Navigation Company, Limited,

CARRYING HIS MAJESTY’S MAILS.
LEAVE— J
LIVERPOOL for WEST AFRICA every WEDNESDAY & SATURDAY
LIVERPOOL for SOUTH-WEST AFRICA THURSDAY Four Weekly

LONDON for WEST AFRICA .. .. THURSDAY Three Weekly
HAMBURG for WEST AFRICA .. .. .. .. Four Times a Month
HAMBURG for LAGOS... .. .. .. .. ws e. Fortnightly
ROTTERDAM for WEST AFRICA .. .. Four Times a Month

TAKING PASSENGERS AT LOW RATES.

GCanadian—South African Line,
CANADA to the CAPE DIRECT.

(Under Contract with the Canadian Government for the con-
veyance of cargo and mails and for the development of trade
with South African Ports.)

First Class modern steamers, fitted with
cold storage accommodation, sail monthly.

ELDER DEMPSTER and Go. Limited,

Head Office: COLONIAL HOUSE, LIVERPOOL.

4, St. Mary Axe, LONDON, E.C.
MANCHESTER. CARDIFF. BIRMINGHAM. HAMBURG.

Advertisements

WEEKS’

ROYAL FIRST PRIZE

e e
Spraying Machinery
Gained the THIRTEEN HIGHEST AWARDS
in 1909, 1910, 1911, and 1912.

BOTH FIRST PRIZES =! Agricuttural Society

(iL

Our Machines have com-
peted at all most
important demonstrations,
including those held by the
Royal Agricultural Society
and those held since, and
have proved themselves
SECOND TO NONE

and hold A :
AN UNBEATEN ROAD TAR SPRAYING
RECORD. MACHINE.

W. WEEKS & SON, Ltd.,

Perseverance Fronworks,

MAIDSTONE, ENGLAND.

Business Established 1742,

Advertisements.

ww? oe Sea ae

OIL TRACTORS

For ploughing and all work on the land; for driving
machinery; for transport work.

MODEL G.—18-20 b.h.p., hauls a 3 furrow plough, hauls up to
5 tons load.
Specially designed for transport over rough land.
Overall width, 63 inches; weight, 2 tons.
Other models: 7, 15, 30 and 50 b.h.p. Prices moderate.

WINDMILLS an OIL ENGINES
ae ZN

F

From 1 to 50 b.h.p.
Galvanized Steel,

Strong, Simple,
Efficient,
Low in price.

PUMPS

Full Range of Single-

For pumping or for ff) and Double-acting,

driving machinery. tube well pumps, &c.

KINGDON & CO., ENGINEERS & CONTRACTORS,
13 & 14a, King Street, Cheapside, London, E.C.

. Advertisements

TERMITES

WILL NOT GO NEAR
TIMBER --

IF TREATED WITH

Termite worker.
These operate in

armies of a quarter Tj 59
of a million and AT LA S A
upwards.

WOOD PRESERVATIVE.

A Rarttway MANAGER writes us,

“Usebd ATLAS ‘A’ FOR YEARS AS A PRO-
TECTIVE AGAINST WHITE ANTS, AND FOUND
IT EXCELLENT.”

A RESIDENT IN BRITISH EAST AFRICA writes us,
‘* T CONSIDER THE PRESERVATIVE A CERTAIN

. ——

CURE FOR WHITE ANTS, AND A-BLESSING TO

ANYONE WHO LIVES IN A COUNTRY INFESTED
WITH THEM.”
eS

Write for booklet giving full particulars of treat-
ment and practical experiences of

The Agri-Horticultural Society
of India

The Transvaal Division of Entomology
Udaipur-Chitor Railway

Royal Engineers, Colombo
AND OTHERS.

Queen Termite, cap-

ATLAS PRESERVATIVE Co., Ltd., tre'rte's 54.000’ per
y ) day. Length of life,
DEPTFORD, LONDON, S.E. 5 to 10 years.

Advertisements

ESTABLISHED 1837.

J.H. RAYNER & Co.,
Cocoa Brokers. .

LIVERPOOL: 11, Old Hall Street.

LONDON: 36/37, Mincing Lane, E.C.

WEEKLY MARKET REPORTS ISSUED.

COCOA ann OTHER PRODUCE
(Rubber, Seeds, Fibre, Copra, Oils, &c.),

HANDLED anv SOLD sy PUBLIC |
AUCTION

(OR PRIVATE TREATY) IN

LONDON anv LIVERPOOL.

Telegrams-—-‘‘ RAYNER, LIVERPOOL.”
‘““RAYNERLON, LONDON.”

Telephones—8114 Central, Liverpool (5 lines).
‘ 3840 and 3841 Avenue, London.

Advertisements

J. M. LEHMANN,

DRESDEN-A. 28, Germany,
THE BEST AND MOST RENOWNED

Machinery for the Manufacture of
Cocoa, Chocolate and Confectionery.

ESTABLISHED 1834. 1,000 WORKMEN.

Latest Improved Types.
In Use all over the World.
Highest Awards at all Exhibitions.

Advertisements

STUART R. COPE,

33, Great Tower Street,
LONDON,
AND

26, Rue Cadet, Paris.

Telegrams:
Teaminster, London. Froisec, Paris.
Telephones: :
Avenue 3105. Louvre 0-26.

SEEDS: .
CARAVONICA COTTON,
ROBUSTA COFFEE,
QUILLOU COFFEE,
MANIHOT GLAZIOVII,
MANIHOT DICHOTOMA,
MANIHOT PIAUHYENSIS,
MANIHOT HEPTAPHYLLA,
GREEN MANURES,
SOYA BEANS, TEA, &c., &.

PLANTS:

HEVEA BRASILIENSIS,
CACAO THEOBROMA,

SPRAYING MACHINES.

The following Leaflets may be'had on application :—

No. 1. Coffee Robusta (also in Spanish). No. 2. Soya Beans.

No. 3. Caravonica Cotton and Desmodium tortuosum. Others

are in preparation, as well as translations of the above into
French and Spanish.

Advertisements

J. C. HARVEY,
Planter & Consulting Tropical Agriculturist,

TROPICAL CONCESSIONS,
SANBORN,
Estado de Vera Cruz, MEXICO

(Cable: Lieber’s or Western Union Codes).

4

Technical examinations of Virgin Forest Lands in Mexico,
Central or South America, containing Castilloa, or Hevea
Rubber or valuable timber trees.

Expert investigations of physical conditions essential to the
planting of Rubber, Cacao, Coffee, Coco-nits or other
cultures, in any part of. the Tropics of either the eastern or
western hemispheres.

Practical, tapping demonstrations, with improved tools,
upon Castilloa Rubber trees ; preparation of ‘product in
marketable form, and siatements ot cost and yield.

‘Confidential reports upon going estates. Also acts as
visiting agent. -

Valuations and estimates.

‘i

Correspondence solicited and ‘references exchanged.

Advertisements

ESTABLISHED 1884.

The Leading Financial Daily of the World.

Che Hinancial Hews

ALL THE NEWS OF
ALL THE MARKETS.

NEW” AND SPECIAL
UP-TO-DATE FEATURES

ITEMS OF IMPORTANT EXCLUSIVE
INFORMATION ARE GIVEN EVERY DAY.

SPECIAL FEATURES:
eee n Special ; THURSDAY—EMPIRE SECTION.
Finance for Women.

MONDAY .

| Oil Engineering ; Rubber Notes;
TUESDAY . | Banking Special ; FRIDAY - { Extendea Rubber List;
‘Extended Oil List. Diamond Special.

Shipping Special; Motors ;
WEDNESDAY { Extended Mining List. SATURDAY—Oil Share Notes.

ON SALE EVERYWHERE.

Advertisement and Editorial Offices:

III, QUEEN VICTORIA STREET, LONDON, E.C.

, "Phones: 6830 CITY (4 lines).
Telegraphic Address: ‘‘ FINEWS, CENT. LONDON” (count as 2 words).

Che MSinancial Tews

IS PUBLISHED DAILY IN FRENCH IN PARIS.
Telephone: 240.06. Telegrams: ‘’ FINEWS, PARIS.”

Offices: 36vis, BOULEVARD HAUSSMANN.

Advertisements

NEWBOLD & Co.,

72-74, Gray’s Inn Road, London, W.C.,

Gstate & Government Laboratory
Cuthts of all kinds.

ACTUAL GRINDERS AND POLISHERS OF EYE
GLASSES AND LENSES, &c., of every description.

All Goods of the highest quality, perfect finish and accuracy.
As we grind the glasses ourselves we can absolutely guarantee this.

SPECIALITES FOR THE TROPICS.

Microscopes, Telescopes, Theodolites, Surveying Instru-

ments, Polariscopes & Optical Goods of all descriptions

for Sugar, Cacao, Rubber, Tea, Cotton and other

Estates’ Work, in the Factory Laboratory, in the

Research Laboratory for the Identification of Pests,
Fungi, &c., and out in the Field.

Orders and Prescriptions in any language carefully executed and despatched
by letter or parcel post by return mail.

Gold, Gold-filled, White Metal and Steel Spectacles and Eye
Glasses, fitted with Pebbles, Cylindrical, Prismatic and other
Lenses according to the most detailed Prescriptions.

EVERYTHING IN THE WAY OF OPTICAL GOODS
SUPPLIED AT THE SHORTEST NOTICE.

Kew Certified Clinical Thermometers.

Advertisements

Adventures in Search of a Living in Spanish~
America.
From Mexico City to Vera Cruz. By A Mepicat. Man.

Seventy Illustrations .from Photograpbs Ly the Author, and
three Maps. Royal 8vo. Price 88. 6d. net, postage 5d.

Household Pests and Household Remedies.

By W. R. BoELTer. Feap. 4to. Price 28. 6d. net, postage 3d.
With numerous Illustrations.

The Rat Problem.

# By W. R. BoetTer. 170 pp., fcap. 4 Price 2s. 6d. net,
postage 4d. With numerous anteteatifig NESE

Metallurgy : A Textbook for Manufacturers,
Foremen, and Workers in the Metal
Industries, with a special considera-
tion of Dental Metallurgy.

By Ap. Frncuet, D.Sc., Lecturer on Metallurgy on the
Academic and Master Courses of the Trade Board of
Hamburg. Demy 8vo. Cloth, lettered. Price 7s. 6d, net.
postage 6d. With r1z Illustrations.

6 Technical Handbooks.

Indispensable to all interested in the subjects of which
they treat. By H. R: Carter, Author of ‘‘ Modern Flax,
Hemp and Jute Spinning.” ey 8vo, strongly bound in cloth
boards, lettered.
1, Cordage Fibres: Their Cultivation, Batrastion and Preparation for
the Market. Illustrated. Price’ 2s. 6d. net.
2. The Manufacture of Linen, Hemp and Jute Fabrics. Illustrated.
Price 3s. 6d. net.
3. Rope, Twine and Thread Making. Illustrated with Full Page Plates.
Price 5s. net.
4. Flax, Hemp and Jute Spinners’ Catechism. Illustrated. Price 7s. 6d. net.
5. Practical Mill and Factory Arithmetic. Price 2s. 6d. net.
6. Bleaching and Dyeing of Flax, Hemp and Jute, Yarns and Fabrics.
. Price 2s. 6d. net.

On Conjugal Happiness: Experiences, Reflec-
tions and Advice of a Medical Man.
By Dr. L. LozwenFetp, Munich, Translated frpm the Third

German Edition by RonaLp B.S. ‘Kroun, M.D.Lond.
M.R.C.S.E. Demy 8vo. Price 78. 6d. net, postage 4d.

“Tropical Life’? Publishing Department,
83-91, GREAT TITCHFIELD: STREET, ‘LONDON, W.

Advertisements

The African Rubber Industry.

-By Curusert Curisry, M.B., C.M.Edin. Profusely
Illustrated. 13s. 6d. net, post free.

Soil and Plant Sanitation on Cacao and
Rubber Estates.

By H. Hamer Smirtu, with an Introduction by Prof. Wynpuam
Dunstan, C.M.G., F.R.S., &c. 700 pages. 118., post free.

The Future of Cacao Planting.

By H. Hame SmirH, with contributions by leading authorities,
and an introduction by SiR Daniet Morris, K.C.M.G.
Price 1s. 2d., post free.

Cacao Planting in the West Indies.

By H. Hamet SmItu. (Out of Print.)

Coco-nuts—the Consols of the East.

By H. Hamet Smit, and F. A. G. Pare, with an Introduction
by Sir W. H. Lever, Bart. 600 pp., 118., post free.

The Fertilisation of Tea.

By Georce A. Cowik. Price 28. 6d., post free.

Aigrettes and Birdskins.

The Truth about their Collection and Export. By
H. Hamev Situ, with Introduction by Sir J. D. Ress,
K.C.LE., M.P., &c. Price 58. post free.

Hausa Superstitions and Customs.

An Introduction to the Folk-Lore and the Folk. By
Major A. J. N. Tremearne, B.A.(Cantab.), F.R.G.S.,
F.R.A.I. With forty-one Illustrations, more than two hundred’
Figures in the Text, and a Map. Med. 8vo, xvi. + 548 pp.,
cloth, gilt lettered. Price 218. net, postage 6d.

“Verb. Sap.’’ on going to West Africa,
Northern and Southern Nigeria and to
the Coasts.

By Capt. Avan Fiexp, F.R.G.S. Third Edition, with Illustra-
tions and Map. Crown 8vo. Price 28. 6d. net, postage 3d.

‘Tropical Life’? Publishing Department,
83-91, GREAT TITCHFIELD STREET, LONDON, W.

23

Advertisements

TROPICAL
Development Association

112, FENCHURCH STREET,
LONDON, E.C,

Estate Agency Department,

Are open to consider propositions for the sale of

RUBBER, TEA, CACAO, COCO-NUTS, OR
OTHER ESTATES.
CONCESSIONS FOR TIMBER, MINING,
WATER RIGHTS, &c.

The Financial Advisers of the Association are
open to help Planters to convert their Properties
into Limited Liability Companies, or to facilitate
their further development where the owners do
not wish to sell outright. Principals only dealt with

Applicants should forward the fullest particulars available to
save unnecessary delay and correspondence, and when practi-

cable reports from accredited authorities.

Advertisements

To Tea and Cacao Planters, &c.

H. Hamev Smiru's Improved Cacao Tree Scrubber. (Pattern B.}

Are your Trees being injured and destroyed by
Mosses, Ferns, and other epiphytes? If so, use

H. HAMEL SMITH'S

IMPROVED

CACAO TREE SCRUBBERS.

Ask for pattern B with Bass Bristles, or pattern D with wire bristles.
Pattern D is pointed at both ends and cannot be used (as pattern B)
on the end of a Bamboo.

As used in San Thome, the West Indies, Ceylon,
Guayaquil, Samoa, Cochin-China, Bahia, &c.

NONE GENUINE UNLESS STAMPED AS ABOVE.

For fuller particulars as to price, samples, Gec., apply to

‘«‘ Tropical Life’’ Advertising Department,
112, Fenchurch Street, London, E.C.

Advertisements

‘BRIDGE’S
CACAO DRYERS

COPRA DRYERS

are worth investigating, so write for our
NEW
PAMPHLET
(50 pages)
which will be

mated by return
FREE
SOME
ENQUIRERS.

— o——_

N.B.—If you want to dry
produce of any kind,
please communicate
with us before going
elsewhere ; address to
the Sole Makers :—

DAVID BRIDGE & CO., LTD.,
Partout Works, CASTLETON, MANCHESTER.
London Office :—35, Queen Victoria Street, E.C.

Advertisements
BRIDGE’S MODERN

RUBBER MACHINERY

FOR PLANTATION AND WILD RUBBERS.

= ee

Patent Type ‘‘ANG” Improved Type ‘‘2B”
Washing and Crépeing Mill. Washing and Crépeing Mill

TTT)

Improved Vacuum Patent ‘‘ UNIVERSAL”

Dryer. Bark Scrap Washer.
SPECIFY BRIDGE’S
BRIDGE’S MACHINERY
PRODUCE
pceiere THE BEST
MACHINERY RUBBER

Latex Smoking Coagulator.

For full particulars, special Catalogues, &c., apply to—

aut, DAVID BRIDGE & Co., Ltd., aftr

CASTLETON, MANCHESTER.
London Office: 35, QUEEN VICTORIA STREET, E.c.

Advertisements

HEYWOOD & BRIDGE’S
Patent Friction Clutches

and Modern Gearing and Hauling Plants.

SAVE POWER, AND WEAR AND TEAR ON
BELTING, ETC.

PREVENT ACCIDENTS.

Dav Date ETON

a wo
CASTLETON MAN

Oreice: 35

To bona-fide inquirers, this book, containing scores of photos of

up-to-date Clutch Drives, is FREE.

Write for your copy (C 12) if you are interested.

DAVID BRIDGE & Co., Ltd.

CASTLETON, MANCHESTER.

Advertisement

Follow the Glan from
<a Castleton, anchester.

Do you plant CACAO?

If so, write us ve Dryers, Polishers, &c., &c.

Do you plant RUBBER?

If so, you need our coagulating, washing, crépeing,
smoking, and other machinery, which are equalled by
none.

Are you interested in Coco-nut and
Vegetable Oil?

If so, we can fit you out from start to finish, and enable
you to utilize all your by-products.

Do you plant FIBRES?

If so, write for particulars of our Decorticator for Sisal
and other Fibres, and also our Baling Presses for packing
same. :

Do you travel in the Tropics?
If so, you will find our machinery everywhere you go.

If all these, the leading planters, find our MCachinery
worth adopting, so will you. Take our advice, therefore,
and write for catalogues to :—

DAVID BRIDGE & Co., Ltd.

PARTOUT WORKS,

CASTLETON, MANCHESTER.

London Office: 35, Queen Victoria Street, E.C.

Advertisements

HOMCO
CASTOR MEAL

An excellent vegetable
form of ammonia for

CACAO,

Rubber Trees, Tea and
Coffee Plants, Sugar
Canes, &c., &c.

MUCH SUPERIOR TO GROUND
CASTOR CAKE.

“ao
“ SOLE MAKERS:

The Hull Oil Manufacturing Co.,

LIMITED,
STONEFERRY, HULL, ENGLAND.

ty
titel

a

Bye

Speer

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