A Process for Roasting Pure Coffee and for Condensing the Steam Produced during the Roasting Operation in Coffee Substitutes or in Sugar, for the Purpose of Extracting the Aroma and Products therefrom.
Year: 1891

page_text: COMPLETE SPECIFICATION.
A Process for Roasting Pure Coffee and for Condensing the Steam
Produced during the Roasting Operation in Coffee Substitutes
or in Sugar, for the Purpose of Extracting the Aroma and
Products therefrom.
I, JULIUS QUAGLIO, of The Bouillon Capsules and Preserve Manufacturing
Company 67 Holzmarkt Strasse, Berlin, Germany, 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 invention has for object, the roasting of pure coffee while simultaneously
condensing the steam or vapour escaping during the roasting operation by means
of powdered coffee substitute or sugar for the purpose of extracting therefrom
in a condensed form, the coffee aroma, the caffeine and other products of the
roasting operation.
It is a well known fact that when pure coffee is roasted valuable compounds
contained in the steam produced in roasting are entirely lost. These compounds
consist, according to the researches of Mr. on Bibra, of liquid oil of crude coffee
beans, of caffeine, coffee aroma, coffee fat, and assamar. These compounds can
be extracted by means of glycerine but are very hard to separate.
These substances can be condensed with the steam in porous pulverized material,
there is thus a chance to extract them usefully. For this purpose the steam
a thick layer, or
escaping during the roasting of the coffee is conveyed through
through several layers of pulverized coffee substitutes, or of sugar, and is thus
condensed. The burnt coffee and the substitute or the sugar can be each used
alone or mixed together. The mixture is then finely pulverized and compressed
directly into tablets or rolls. To carry out this process, the following apparatus
may be employed:
1. Drum roasting, Figure 1 longitudinal section. Figure 2 section through
line a b, and Figure 3 a section through line cd of Figure 1. A is a metal drum
furnished with a tightly closing lid with a central channel P for scooping and with
a sieve pipe B. C is a protecting sheet preventing the direct contact of the flames.
D is any suitable source of heat, E is a connection between the drum A. and the
drum F in which is arranged a sieve cylinder G, a side cover o and a sieve
tube H; this drum turns below in a water cooling tank I. The two drums can
be easily removed in order to be filled or emptied in consequence of the open
bearing N and of the ball bearing K. The steam escapes through the pipe L
which can be connected to an aspirator. The apparatus operates as follows:-
The drum A is charged with crude coffee beans to about one third of its height
while the sieve cylinder G is filled with the powdered coffee substitute or sugar.
As the roasting proceeds, the steam from the drum A passes through the sieve
pipe B and connection E in which the empyreumatic oil is partly condensed, and
is conveyed to the drum F so as to surround the drum G through the perforations
of which it enters, passing through the layer of powder on its way to the sieve
pipe H wherefrom it escapes at L after having left its compounds in the said
powder.
Figure 4 shows another form of revolving apparatus in which A is a metal
cylinder having a cover M and likewise filled to a third of its height with pure
coffee. G is a sieve cylinder filled with substitute; B is a sieve pipe. Lan
outlet pipe. D the heater. In this case, the steam passes directly into the sieve
cylinder wherein its compounds are absorbed and escape finally through the sieve
pipe.
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page_text: stirring mechanism B and a protecting sheet C.. D any suitable source of heat-
E the pipe connecting the receptacle A. with the vessel K furnished with a
cover G, and F is a cylinder with an iron pipe G which is tightly closed over the
pipe E.
His a sieve bottom. I is the cooling vessel, and the outlet pipe.
The pure coffee is roasted in A, while F is filled with powder. The steam
traverses the latter from top to bottom, passes through the sieve bottom H on its
way to K and escapes at L. The vertical arrangement may also be carried
horizontally.
The source of heat can be replaced by superheated steam or by hot carbonic
acid, which may be conveyed directly into the roasting cylinder.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
The roasting of pure coffee while simultaneously condensing the steam or vapour
escaping during the roasting operation by means of powdered coffee substitute or
sugar. for the purpose of extracting therefrom in a condensed form the coffee aroma,
the caffeine and other products of the roasting operation, substantially as described.
Dated this: 28th day of October 1891.
H. GARDNER,
Patent Agent, 166, Fleet Street, London, Agent for the said Julius Quaglio.