Improved Method for Utilizing the Vapours Developed in Roasting Coffee and the like.
Year: 1896

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the Patents, &c. Act, 1883), as allowed by
the decision of the Comptroller General. of the 5th day of July 1898.
Date of Application, 6th Nov., 1896
Complete Specification Left, 26th July, 1897-Accepted, 4th Sept., 1897
Improved Method for Utilizing the Vapours Developed in Roasting
Coffee and the like.
A communication from BERNHARD THEODOR BACKSTROM, of Hernosand, in the
Kingdom of Sweden, Merchant.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention to be as
follows:-
In roasting coffee in the usual way in vessels open or insufficiently closed, a
certain quantity of aqueous vapours and other volatile worthless gases are
developed in the earlier stage of roasting. Towards the end of the operation, on
the contrary, a considerable quantity of aromatic substances escapes, the result
of which will be a much reduced value of the final product.
In order to prevent to a certain degree, the loss of those aromatic substances,
it has been proposed to roast the coffee in vessels which are kept open while the
aqueous substances etc. are driven out, but which are then closed and remain
closed during the last period of the roasting process. This method will, to be
sure, allow the retaining of a small quantity of the useful vapours, which re-
enter the coffee while it is cooling, but the greater portion of them is lost through
condensation on the interior walls of the closed vessel.
The present invention relates to a method of collecting and utilizing these
aromatic vapours developed during the final period of the roasting, by bringing
the coffee into the presence of an appropriate substitute for coffee which will
absorb said vapours while they are developing.
To this end I have constructed an apparatus having two chambers communi-
cating with each other by a perforated partition a tube, or a simple hole, and
provided with apertures which can be closed at will.
In one of these chambers I introduce a certain quantity of unroasted coffee and
begin roasting it, keeping the said apertures open. For a certain period the
coffee will develop vapours of water, etc., and then all development ceases. I now
bring into the other chamber a proportional quantity of an appropriate substitute,
for instance chicory, celulose, or the like then I close all apertures, and the roast-
ing is continued. During this period the coffee will develop aromatic vapours,
filling the chamber and passing into the other chamber where they are absorbed
by the substitute.
In this way, I get on the one hand a well roasted coffee and on the other a

page_text: substitute the worth of which is heightened, owing to the considerable quantity of
genuine coffee aroma, which tit has absorbed... This substitute, can-be furthermore
perfected by other, additions.,
The apparatus may be constructed in various ways, for a rotary or reciprocating
movement. The substitute may be ground in the usual manner, or pressed into
cakes etc. But it can also be advantageously..mixed. with roasted coffee.
The method above described can also be applied to roasting cocoa and the like.
Dated this 6th day of November 1896.
BOULT & WADE,
Agents for the "Applicant.
Improved Method for Utilizing the Vapours Developed in Roasting
Coffee and the like.
A communication from BERNHARD THEODOR BACKSTRÖM, of Hernösand, in the
Kingdom of Sweden, Merchant.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention, and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
In roasting coffee in the usual way in open or insufficiently closed vessels, a
certain quantity of aqueous vapours and other volatile and worthless gases are
developed in an early stage of the roasting. Towards the end of the operation,
on the contrary, a considerable quantity of aromatic substances escapes, the
result of which will be a much reduced value of the final product.
In order to prevent, to a certain degree, the loss of these aromatic substances,
it has been proposed to roast the coffee in vessels, which are kept open; while the
aqueous substances, &c., are driven out, but which are then closed, during the
last period of the roasting process. This method will effect the retention of a
small quantity of the useful vapours, which re-enter the coffee while it is cooling,
but the greater portion of them is lost by condensation on the interior walls of
the closed vessel.
The present invention relates principally to a method of collecting and utiliz-
ing these aromatic vapours developed during the final period of the roasting by
bringing the coffee into the presence of an appropriate substitute for coffee, which
will absorb said vapours as they are developed.
To this end, two receptacles are employed communicating with each other by
means of a perforated partition, a tube or a simple passage and provided with
apertures, which can be closed at will.
In one of these chambers a certain quantity of unroasted coffee is introduced
and partly roasted, the said apparatus being kept open. For a certain period
the coffee will develop aqueous vapours &c. and then all development ceases. A
proportional quantity of an appropriate substitute which may have been previously
roasted, if the nature of it should require, for instance chicory, cellulose or the
like, is placed in the other chamber, all apertures are closed and the roasting of
the coffee is continued. During this period the coffee will develop aromatic
vapours filling its chamber and passing into the other chamber, where they will
be absorbed by the substitute.
The apparatus may be constructed in various ways for a rotary or reciprocating
movement. Preferably the apparatus consists of two vessels in the form of

page_text: truncated cones having their smaller ends turned towards each other and com-
municating by tubes joined telescopically. In the smaller vessel the coffee is
introduced and in the larger the substitute, whereupon the vessels are set in a
rotary motion, the smaller vessel being heated by any appropriate means.
In order to facilitate the absorption of the vapours by the substitute the known
fact is made use of that fatty substances have in a high degree the quality of
absorbing aromas. Accordingly the substitute, before bringing it into the
presence of the aromatic vapours may be treated with a purified fat or oil, such
as almond oil or the like. This addition of a fatty substance not only facilitates
the Cabsorption of the aromas, but also tends to retain them. This method is a
very rational one, since coffee itself contains a considerable quantity of oil, which
certainly contributes to retain its aroma, when roasted.
In this way is obtained on the one hand a well roasted coffee and on the other
a substitute, the value of which is increased, owing to the considerable quantity
of genuine coffee aroma, which it has absorbed.
Meanwhile the substitute still lacks the most important of the ingredients of
coffee, namely caffein, which first evaporates at a very high temperature and sub-
limates as soon as the temperature sinks, so that it is impossible to absorb it into
the substitute in the manner described. The caffein seems to play no great part
in the taste of the coffee, but it is thought to have some physiological effects,
which it is desirable for the substitute to bring about. For this purpose, the
substitute treated as before described is infused with a solution of caffein, which
may be extracted from coffee or synthetically produced. It has been proposed to
add caffein to a substitute which was afterwards roasted, but since the caffein
sublimates, as aforesaid, there is a risk of loosing the said addition during the
process of roasting, which risk is entirely done away with by this method.
The substitute thus prepared may be ground in the usual way or pressed into
cakes &c. But it can also be advantageously mixed with roasted coffee.
The method described can be applied in an analogous manner to roasting
cocoa and similar substances.
Having now particularly described and ascertained the nature of the said in-
vention as communicated to me by my foreign correspondent, I declare that what
I claim is:
1. A coffee substitute saturated with coffee aroma obtained by the process
described and subsequently treated with a solution of caffein substantially .as
described.
2. A coffee compound consisting of a mixture of pure coffee and a substitute
treated in the manner described substantially as described.
3. In the process substantially as described the addition of a fatty substance
to the substitute before bringing it into the presence of the vapours developed
out of the coffee.
Dated this 24th day of July 1897.
BOULT & WADE,
Agents for the Applicant.