Improvements in and connected with the Process of Extracting Cocoa, or Rendering it Soluble for the Preparation of Soluble Cocoa, or the Manufacture of Cocoa Powder, Chocolate, and the like Preparations.
Year: 1891

page_text: Date of Application, 24th Nov., 1891-Accepted, 19th Nov., 1892
COMPLETE SPECIFICATION.
Improvements in and connected with the Process of Extracting Cocoa,
or Rendering it Soluble for the Preparation of Soluble Cocoa, or
the Manufacture of Cocoa Powder, Chocolate, and the like
Preparations.
A communication by MOSER & Co., of Stuttgart, in the Empire of Germany,
Chocolate Manufacturers.
1. WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E. of the Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool and 6 Bank Street Manchester,
both in the County of Lancaster and 323 High Holborn in the County of
Middlesex, Civil Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This process for rendering cocoa soluble, and its further treatment for use in the
manufacture of cocoa and chocolate, differs so essentially from all previously
patented or unpatented processes, and yields such important advantages whereby
the widest extension of the manufacture in question, will be secured, that a detailed
description of the same is unconditionally necessary.
Briefly stated, this process is composed of the following methods of treatment in
the order hereinafter given
1. The raw cacao beans as received from the Colonies are shelled and thoroughly
cleansed from the husks as well as the dust.
2. The raw cacao kernels thus purified are prepared by means of steam, which is
charged with more or less ammoniacal gas according to the amount of acid con-
tained in the beans. The steam employed should be of a temperature of 80 to
90 degrees, in any case under 100 degrees centigrade.
3. The cacao kernels prepared according to the preceding paragraph No. 2 and
thus rendered soluble are then roasted at a temperature of from 122 to 132 degrees
centigrade, the first of these temperatures must be reached but the latter must not
be exceeded, the temperature to be employed generally ranges between the limits
named according to the quality of the beans.
4. The cocoa thus rendered soluble, and having, in consequence of the roasting,
its full aroma, is then pulverised, preferably by means of a horizontal cocoa mill,
such as is usually employed at present, as this least affects the fleeting and delicate
aroma.
5. A portion of the fat (about 31 to 33 per cent.) is then removed by pressure
from the liquid mass of cocoa whilst in a warm condition; and
6. The residue, after the pressing, is pulverised and sifted and is then ready for
use without any addition of spices or the like substances.
It must be observed that, for dissolving the cocoa, alkali is indispensably
necessary in order to change the acid character of the albuminoids into a neutral
one, it is for this purpose that volatile ammoniacal gas is employed, which has the
characteristic of again entirely volatilising off along with the steam, that is, it is
again entirely removed from the cocoa beans by means of the heat resulting from
the subsequent roasting.
A definite percentage of ammoniacal gas in the steam bath cannot be easily fixed
upon, as that depends upon the amount of acid in the cocoa beans, usually the
addition of 0.5 to 3% of the ammoniacal gas to the cocoa beans may be allowed.
The process is conducted in the following manner, and for the better under-
standing of the invention there is annexed hereto a sheet of illustrative drawings,
to which reference is hereinafter made:-
:-
About 100 pounds of shelled purified raw cocoa beans are placed in a drum or

page_text: receptacle A capable of being rotated, and the beans are moistened with about
2 litres of water. The axis of the drum A is hollow and is provided with holes, it
is connected by means of a pipe a with a closed vessel B, into which are introduced
5 to 10 litres of cold water and 0.5 to 3 pounds of volatile ammonium carbonate.
The vessel B is then cut off and is heated by steam or other medium introduced
into it. The liquid carbonate of ammonium then becomes gaseous, combining with
the steam, and, the vessel B being opened, enters by means of the pipe a and
the hollow axis of A into the drum A, where it is quickly absorbed by the
moistened cocoa beans. After a period of from half an hour to three quarters of an
hour, during which period the water in the vessel should not exceed a temperature
of 90° centigrade, the cocoa is dissolved. The connection between A and B is then
closed, and the rotation of the drum A ceased, and the cocoa in the drum is allowed
to stand for from two to three hours. It is then placed in the roasting apparatus
(of any suitable kind) and subjected to further treatment as previously mentioned.
Before the advantages of this new process are more particularly explained, the
processes previously in use & their disadvantages must be first briefly enumerated..
As is well known, in order to obtain the kernel which is employed for making
cocoa and chocolate. the flesh of the fruit must be first removed. This is performed
while still in the Colonies by the cocoa fruit being piled up in trenches or heaps
and subjected to fermentation. The flesh of the fruit putrifies during this operation,
and forms a disagreeable paste, from which the kernels (cacao beans) are separated
by mixing the pasty mass with sand, the mass combines with the sand, and then the
beans are dried in the sun. The less valuable ordinary beans are cbtained in
another way. By either process, it is impossible to remove entirely some fragments
of the flesh from the beans.
In the methods of manufacture hitherto employed, these cacao beans, together
with their husks and the portions of flesh thereto adherent, are first roasted, when
these impurities, through the heat and the constant friction of the beans against
each other or against the roasting drum, are, to a large extent, converted into dust
which is partly consumed, giving off malodorous gases, and the fine cocoa aroma
developed by the roasting is impaired, and, by its penetration into the interior of
the beans, it must act deleteriously on the aroma, and this deleterious partially
carbonised dust combines, in part, with the bean kernels which, by the roasting,
are freed from their husks and broken into larger or smaller particles, and it
adheres so much the more firmly thereto, owing to the partial exudation of the fat
from the cells in consequence of the heat causing these particles to become sticky,
and this dust cannot be again removed from the cocoa, even when deleterious
shelling and purifying processes are made use of. The quality and taste are,
however, harmed thereby. These drawbacks have been long recognised, and
attempts have been made to remove the same by means of roasting apparatus; in
some cases patented, of the most varied kind, but without result.
Both evils are entirely removed by this new process, as the husks of the beans,
together with the impurities thereto adherent, are already previously removed, and
thus can in no wise exercise an unfavourable influence.
After the husking and purifying of the roasted cacao have been completed, it is,
by many manufacturers, again placed a second time in the roasting apparatus, in
accordance with a method employed in practice since about the year 1885, and
treated, whilst heated, by means of alkalies and other chemicals in the presence
of water, by which the products of decomposition are certainly removed by the
evaporation of the water, but also a portion of the aroma is carried off with it."
These methods of husking are, however, always preferable to those in which the
husking is not performed until after the dividing or grinding of the cocoa has been
completed. For this, alkalies in a dissolved condition were employed, for which 3
to 4 per cent. water (calculated on the whole mass of cacao) was necessary in order
to bring each particle of the mass into contact with the purifying substance,
otherwise, it was impossible to render it soluble. This large addition of water
must be afterwards removed by means of heat, and the greater part of the aroma

page_text: evaporates with it, as, owing to the fine subdivision of the mass, a large portion of
the cells is mechanically torn open and many of the cells are opened by the action
of the chemicals so that no obstacle remains to prevent the escape of the aroma.
The colour is also affected. It was necessary to conceal artificially both these
evils by means of spices and colourings.
A still worse result was produced by the attempt to perform the husking, without
the use of alkalies, by means of high pressure steam of 5 or 6 atmospheres at a
temperature, therefore, of over 150 degrees centigrade; if it be considered that
the solubility of the cacao consists of nothing else than the conversion, into a
soluble condition, of the albuminoids contained in an acid condition in the cacao
in which they are insoluble, and with difficulty digested in the mechanical digesting
apparatus. The acid condition of the albuminoids must be changed into a neutral
one, as slightly alkaline as possible. It is impossible to attain this result with
the addition of alkali, if only a little. Neither the great heat nor the high
pressure of the steam, as in the above process, can effect this result, on the other
hand, they have only a deleterious effect, as it is well known that the aroma of
cocoa may be completely changed or entirely destroyed at a temperature of about
140 degrees centigrade. The quantity of water is further increased by the conden-
sation of the steam, which must necessarily be re-evaporated and thereby the
goodness of the product is again strongly affected. There can be no question of
an improvement of the product, on the contrary, in this process, the object of the
rendering soluble is entirely missed, as no improvement is effected but a worse
result. By the use of heat and pressure, the cocoa starch is indeed partially
converted into dextrine, which, however, is equally produced by the roasting
process, and is the case also in a still more complete manner by this new process
through the moistening of the starch by means of a steam bath.
In the course of the further treatment by the processes at present employed, the
fat is pressed out of the cocoa mass while in a wet condition, and the mass is then
dried, or the mass is first dried in a drying chamber and then pressed. The
residue, after being pressed, is then pulverised and the spices and colouring
substances are then added, which, owing to the faults of the previous processes,
were necessary.
This new process offers the following advantages as against the drawbacks above
enumerated of the methods of manufacture hitherto employed :-
By the entire removal of the husks, together with decayed particles thereto.
adherent, from the cacao beans, the cocoa comes into the roasting apparatus in a
quite pure already husked condition, and no combustible gases can possibly be
evolved during the roasting, as no material is present for producing the same, and,
consequently, the quality of the cocoa cannot be deteriorated. As the rendering
soluble of the cocoa, that is to say, the transforming of the acid condition.
of the cocoa beans into a slightly alkaline one, takes place in a
raw but.
purified condition, and at a temperature of less than 100 degrees centigrade, whilst.
the development of the aroma requires at least a temperature of over 100 degrees.
centigrade, so that no deleterious effect whatsoever can be exerted on the aroma
either during the conversion or by the moisture employed during the same, or by
the gases developed. A temperature of over 100 degrees is only employed in the
final roasting when, before the actual development of the aroma, the moisture, the
gases of decomposition and the ammoniacal vapours employed for neutralising,.
are first evaporated, and there is, therefore, no hindrance to the subsequent
development of the natural fine aroma peculiar to the cocoa, but, on the other
hand, it is fully produced, that is to say, a cocoa product is obtained with a full,
unweakened aroma not affected or rendered impure by anything, and which requires
no treatment for concealing errors in the manufacture.
The yield of ash is also not increased, but generally rather diminished by the
use of volatile alkalies, as, thereby, the bean kernels are treated in a much
cleaner condition.
An advantage of quite peculiar importance of this new process, against the

page_text: existing ones, is that the finished product does not become useless if kept long
in stock, as it does at present, or at least lose the remaining aroma and become
of a peaty consistency, in a word, tasteless. This evil is mainly to be attributed
to the fact that an addition of water or steam, after the roasting, can never
again be removed either from the prepared ground mass or from the finished
product, except by heating it for a long time to 100 degrees centigrade. This
treatment cannot, however, be carried out in practice, as the fat still contained
in the mass or the finished product hinders the complete evaporation of the water.
As in this new process moisture only comes in contact with the cocoa whilst
the beans are in a raw condition for the purpose of rendering them soluble, and
as this moisture is removed by the supplementary roasting, before the development
of the aroma, for which a temperature of from 122 degrees to 132 degrees
centigrade is requisite, no trace of moisture can be left in the cocoa and thus
the unconditional keeping quality or unchangeability of the finished product is
permanently guaranteed.
This process may naturally not only be employed for the production of easily
soluble cocoa powder but also for other preparations of cocoa, such as chocolate
and the like, and it is to be preferred to any other method, as only purified beans
with fully developed fine natural aroma are employed or are used for the supple-
mentary processes, and the various substances are ready for being manufactured in
a fully soluble and easily digestible condition.
The solubility of the cocoa produced by this new process is also considerably
increased, as the albuminoids are already converted into albumose before they
are exposed to a high temperature, and, thereby, rendered less easily soluble, by
means of the alkali (which is subsequently evaporated during the roasting); this
albumose loses nothing more of its solubility by subsequent heating.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is
1. The improved process for rendering cocoa soluble, consisting in subjecting the
raw cacao beans, after being husked and purified from husks and dust, to the action
of a steam bath of less than 100 degrees centigrade (that is, without using pressure)
preferably at 80 to 90 degrees centigrade, for the purpose of rendering it soluble
before the roasting, which bath receives a slight addition of ammonia or ammoniacal
salts which are volatilized by supplemental heat.
2. The improvements in the treatment or preparation of cocoa, consisting in
roasting the cocoa, after it has been rendered soluble as described in Claim 1, at
a temperature of 122 to 132 degrees centigrade, whereby all moisture and the
slight excess of alkali from the steam bath are evaporated before the actual
development of the aroma of the cocoa takes place, and the latter can be completed
in an entirely uninterrupted manner.
3. The application of the cocoa rendered soluble as described in Claims 1 and 2
to the manufacture of cocoa powder, chocolate and the like preparations.
Dated this 23rd day of November 1891.
WM. P. THOMPSON & Co.,
Agents for the Applicant.