AN IMPROVED METHOD OR PROCESS OF AND APPARATUS FOR EXTRACTING ESSENTIAL OILS FROM HOPS OR OTHER PLANTS
Year: 1883

page_text: LETTERS PATENT to William Robert Lake, of the firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings London for an Invention
of AN IMPROVED METHOD OR PROCESS OF AND APPARATUS FOR EXTRACTING
ESSENTIAL OILS FROM HOPS OR OTHER PLANTS." communicated to him from
PROVISIONAL SPECIFICATION left by the said William Robert Lake at
the Office of the. Commissioners of Patents on the 5th October 1883.
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake and Co, Patent Agents,
Southampton Buildings, London "AN IMPROVED METHOD OR PROCESS OF AND
APPARATUS FOR EXTRACTING ESSENTIAL OILS FROM HOPS OR OTHER PLANTS,"
A communication to him from abroad by Théophile Auguste Breithaupt, of
Strasbourg Alsace.]
This invention relates chiefly to an improved method or process of and apparatus
for extracting essential oils from hops and other plants.
In this process the separation of the volatile parts of the plants is effected by
means of compressed air, the air constituting the carrying agent for the essential
vapours. This process avoids all loss or evaporation of the volatile products,
whatever may be the nature of the plant treated.
The application of the said process to hops, which constitutes the main feature
of the said invention, enables me to obtain hops deprived of their volatile essence,
which hops when dried can be kept for a very long time without deteriorating,
because the bitter tannic and resinous principles which they contain are not in any
way modified by the said process; and the essential oil which they contain being
removed, the changes that are peculiar to this part of the plant cannot take place;
beer can therefore be manufactured economically from these hops preserved and
deprived of their essential oils.
On the other hand the oil extracted by the process herein describe I can be used.
in commerce or it can be converted into a special product to which I give the nam
of "essential aroma of hops" and which when added to beer cold, serves to improve

page_text: its quality and to preserve it in any season, by preventing any acid and putrid
fermentation of this liquor.
The said improved process of extraction consists in first heating the hops (which
have been newly dried) by means of steam in such a manner as to break up the
cuticles of the plant which contain this oil, then to force through them in a closed
vessel or receptacle a sufficient volume of air to raise the pressure therein to two or
three atmospheres, the volatilized oil mixes intimately with this air, and the said
vessel is then placed in communication with another vessel in which a vacuum
has been formed, care being had to circulate a refrigerant around the communication
pipe; in this manner the air charged with essential vapours passes into the separator
vessel, wherein the vapours cooled by the refrigerant condense, and the resulting
liquid collects in a receptacle placed at the bottom of the said vessel.
It will be understood that it is easy to repeat the operation several times, so as
to effect the complete extraction of the essential oil contained in the mass of hops
under treatment, and fresh hops may then be introduced and treated in the same
manner.
In order to carry on the process above described, I employ very simple apparatus
which I will now proceed to describe.
I provide a cylindrical vessel, preferably of copper, into which the newly dried
hops are introduced. This vessel is provided externally with a sheet metal casing
and is closed at its upper part by a top or cover communicating by means of a cock
with a serpentine pipe placed in a metal casing filled with cold water. The
extremity of the said serpentine pipe enters a cylindrical vessel similar to that
which receives the hops, in which vessel a vacuum is formed by means of a pump
with which it communicates by a pipe provided with a cock.
The first named vessel is provided at its lower part with a perforated false
bottom upon which the hops are placed and below which is a pipe for conducting
the steam to the said vessel, and a pipe for the entrance of the compressed air;
another pipe serves to introduce steam into the sheet metal casing.
Below the second or separating vessel, which terminates at its upper end in a
conical part provided with a cock, is placed a receptacle designed to collect the
essential oil and so arranged that it will close hermetically.
The apparatus being thus arranged and the first named vessel being filled with
hops, steam is introduced into the sheet metal casing in order to raise the tempe-
rature, and a slight current of steam is admitted into the first named vessel in
order to break up the cuticles containing the essential oil; the steam in the sheet
metal casing rapidly raises the temperature of the hops, without any material
condensation of the steam, and maintains in the interior of the apparatus &
temperature of about 80 degrees centigrade.
Atmospheric air under pressure is then admitted into the vessel containing the
hops, either from a special receptacle or from the aforesaid pump, so as to raise
the pressure in the said vessel to about two atmospheres; the essential vapour
of the hops being then mixed with, and dissolved in, the said compressed air, the
cocks on the steam pipes and the compressed air pipe are closed, and the cock
which puts the top or cover of the first named vessel in communication with the
serpentine pipe and with the vessel in which the vacuum is formed, is opened.
At this moment the heated compressed air from the first named vessel, containing
the volatilized essential oil, as well as a small quantity of steam, passes into the
vessel in which the vacuum is formed; but by passing through the serpentine
pipe, the vapours are cooled and condense and deposit in a liquid state in the said
vessel at the lower part of which the resulting liquid collects; then by opening the
cock below, this essential and aromatic liquid will descend into the collective
receptacle.
By repeating this operation two or three times, the hops are completely deprived
of the essential oil, and can, after drying, be packed and be kept for vears if

page_text: In order to avoid any loss of the essential vapour proceeding from the part of
this essence which is not condensed by the cooling and which remains in suspension
in the air which has served for its extraction, I employ the same air over again
for effecting the transport of the said essence from the first named vessel into the
separating vessel, or vessel in which the vacuum is formed, and I proceed in the
following manner, that is to say; by the aid of the aforesaid pump, I force into
the first named vessel the air contained in the separating vessel, so that (as the
two vessels are of the same capacity) a vacuum will be produced in the separating*
vessel and the pressure will be raised to two atmospheres in the first named vessel;
then the two vessels are placed in communication with each other and the greater
part of these vapours, cooled by the interposed refrigerating serpentine pipe, pass
into the separating vessel where they condense; a vacuum is again formed in the
separating vessel by means of the said pump, the air being again forced into the.
first named vessel; after repeating this operation two or three times the two
vessels are left in communication with each other and a quantity of pure air is
forced into the first named vessel by the said pump in order to displace the whole
of the air still containing essential vapours and force it into the separator vessel;
the first named vessel can then be emptied without appreciable loss and the hops
which have been treated can be replaced by fresh hops.
In this manner the loss of the essential oil is inappreciable and the hops come
from the apparatus very dry and entirely freed from the volatile matter which
they contained.
On the other hand the essential liquid which accumulates in the collecting
receptacle may be used in commerce, for improving the quality of beer or to be
converted into a more perfect product as above stated.
•
I obtain this product in the following manner that is to say, I dissolve from
fifteen to twenty grammes of the essence of hops obtained in the manner above
indicated in one litre of pure alcohol, I add fifty centigrammes of calcined magnesia
and I add, over and over again, the oxygenated part of the essence called the
stearoptene which forms, with the magnesia, a saponification which separates by
filtration, whilst the other part, non-oxygenated or hydro-carburetted, called
elioptene (élioptone) dissolves in the alcohol and passes off clear and limpid.
The latter product which constitutes the essential aroma of the hops, added
before or after the fermentation, communicates to beer, the fine natural aroma
of the hops and assists in preserving the beer by preventing lacteal and acetic
fermentation.
The aroma called bock ale, that is to say which is designed to be introduced
into beer known under the name of ale, is obtained by the addition of five grammes
of essence of orange leaves per litre; the aroma of Pilsen, for beer known under
that name is obtained by the addition of two grammes of essence of pine per litre.
It will be understood that the process of extracting the essential oils from hops as
above described may be applied with equal advantage to other kinds of vegetable
substances from which it is desired to separate the essential liquids that they
contain; the form and arrangement of the apparatus for carrying on the said
process, can be varied according to the nature of the materials to be treated.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Robert Lake in the Patent Office on the 5th April
1884.
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and Co. Patent Agents,
Southampton Buildings, London. "AN IMPROVED METHOD OR PROCESS OF AND
APPARATUS FOR EXTRACTING ESSENTIAL OILS FROM HOPS OR OTHER PLANTS
"
A communication to me from abroad by Théophile Auguste Breithaupt, of
Strasbourg, Alsace.
This invention relates chiefly to an improved method or process of and apparatus
for extracting essential oils from hops and other plants.
In this process the separation of the volatile parts of the plants is effected by
means of compressed air, this air constituting the carrying agent for the essential
vapours. This process avoids all loss or evaporation of the volatile products,
whatever may be the nature of the plant treated.
.The application of the said process to hops, which constitutes the main featuré
of the said invention, enables me to obtain hops deprived of their volatile essence,
which hops when dried can be preserved for a very long time without deteriorating,
because the bitter tannic and resinous principles which they contain are not in any
way modified by the said process.; and the essential oil which they also contain
being removed, the changes peculiar to this part of the plant cannot take place;
Beer of good quality can be manufactured economically by the use of these hops
preserved and deprived of their essential oils.
"
The oil extracted by the process herein described can be used in commerce, or it
can be converted into a special product which I term " essential aroma of hops
and which when added in a cold state to beer serves to improve its quality and
ensures its preservation in any season, by preventing any acid and putrid
fermentation thereof.
The said improved process of extraction consists in first heating hops (which
have been newly dried) by means of steam in such a manner as to burst the
cuticles of the plant which contain this oil, then forcing through them in the
closed vessel or receptacle in which the operation is carried on a sufficient volume
of air to raise the pressure therein to two or three atmospheres, the volatilized oil
mixing intimately with this air, and then placing the said vessel in communication
with another vessel in which a vacuum has been formed, care being taken to
surround the communication pipe with a cooling agent or refrigerant. In this
manner the air charged with essential vapours passes into the separator vessel,
wherein the vapours cooled by the refrigerant condense, and the resulting liquid
collects in a receptacle placed below the said vessel.
It will be understood that it is easy to repeat the operation several times, so as
to effect the complete extraction of the essential oil contained in the mass of hops
under treatment%3B fresh hops may then be introduced and treated in the same
manner.
In order to carry on the process above described, I employ very simple apparatus
which I will now proceed to describe.
In the accompanying drawings
Figure 1 is a front elevation of one form of the said apparatus partly in
section
Figure 2 is a view of a duplex apparatus that is to say an apparatus comprising
two hop stills, and Figure 3 is a view illustrating another modification

page_text: The newly dried hops are introduced into a cylindrical copper still A, Figure 1,
provided externally with a sheet metal casing B, and closed at its upper part by
an alembic C communicating by means of a cock D with a serpentine pipe E
placed in a metal casing F filled with cold water. One extremity of the serpentine
pipe E enters a cylindrical vessel F¹ similar to that which contains the hops, in
which vessel a vacuum is formed by means of a pump G with which it communicates
by a pipe H provided with a cock I
The still A is provided at its lower part with a perforated false bottom M upon
which the hops are placed and below which is a pipe J for conducting steam to
the said vessel, and with a pipe K through which compressed air is forced; another
pipe L serves to introduce steam into the sheet-metal casing B.
Below the separating vessel F¹, which terminates at its lower end in a conical
part provided with a cock N, is placed a receptacle O designed to collect the
essential oil and so arranged that it can be closed hermetically.
The apparatus being thus arranged and the still A being filled with hops, steam
is introduced into the sheet metal casing B in order to raise the temperature
thereof, and a slight current of steam is admitted into the said still A in order to
burst the cuticles of the hops containing the essential oil. The steam in the sheet
metal casing B rapidly raises the temperature of the hops without any material
condensation of the steam, and maintains in the interior of the apparatus a
temperature of about 80 degrees centigrade
Atmospheric air under pressure is then admitted into the still A either from a
special receptacle or from the aforesaid pump G so as to raise the pressure in the
said still A to about two atmospheres; the essential vapour of the hops being then
mixed with and dissolved in the said compressed air, the cocks in the steam
pipes J and L and the compressed air pipe K are closed, and the cock D (which
puts the alembic of the still in communication with the serpentine pipe E and
with the vessel F¹ in which the vacuum is formed by means of the air pump G) is
opened
At this moment the heated compressed air from the still A containing the
volatilized essential oil as well as a small quantity of steam, passes into the
vessel F¹ but by passing through the serpentine pipe E, the vapours are condensed
and deposited in a liquid state in the said vessel F¹ at the lower part of which
the resulting liquid collects. By opening the cock N this essential and aromatic
liquid will descend into the collecting receptacle O.
By repeating this operation two or three times the hops are completely deprived
of the essential oil, and can, after drying, be packed and preserved for years if
necessary
In order to avoid the loss of essential vapour which is not condensed by the
cooling and which remains in suspension in the air which has served for its
transportation, I employ the same air repeatedly for effecting the transport of the
said essence from the still A into the vessel F¹, and I proceed in the following
manner, that is to say ;-By means of the aforesaid pump G, I force into the
still A, the air contained in the vessel F' so that (as the two vessels are of the same
capacity) a vacuum will be produced in the vessel F¹ and the pressure will be
raised to two atmospheres in the still A. The two vessels are then placed in
communication with each other and the greater part of the vapours cooled by the
interposed refrigerating serpentine pipe E pass into the separating vessel where
they condense; a vacuum is again formed in the separating vessel by means of the
same pump G the air being again forced into the still A. After repeating this
operation two or three times the two vessels are left in communication with each
other and a quantity of pure air is forced into the still A by the said pump in
order to displace the whole of the air still containing essential vapours and force it
into the vessel F; the still A can then be emptied without appreciable loss and
the hops which have been treated can be replaced by fresh hops which are treated
in the same manner by forcing into the still A, previously heated by steam, the
air stored in the vessel F and which has served in the preceding operations,

page_text: In this process the loss of the essential oil is inappreciable and the hops come
from the apparatus dry and entirely freed from the volatile matter which they
contained
The essential liquid which accumulates in the collecting receptacle O may be
used in commerce for improving the quality of beer, or may be previously
converted into a purified and rectified product which I term "essential aroma of
hops"
I have shewn in Figure 2 in the accompanying drawings a modified form of
apparatus which comprises two hop stills, the coil E being dispensed with.
The air receiver a is enclosed in a double casing b and into the lower part of the
said casing cold water is introduced which runs out at its upper part. In the
centre of this receiver a is placed a hollow cylinder c containing ice in order to
cool the gases and vapors contained in the apparatus
The receiver a is; provided with pipes d, which connect the same with two
hop stills g, gand with a pipe e designed to connect the said receiver with the air
pump f.
A thermometer K and a vacuum gauge fitted upon the outer cover of the
receiver allow the operation of the apparatus to be readily controlled.
The two stills g, g are alternately supplied with hops, the products from
which are successively conveyed into the air receiver a which operates thus
uninterruptedly whilst the stills g, g are being loaded.
The said stills g, g are in a similar manner to the still A supplied with steam
through the pipe h and connected with the air-pump ƒ by the pipe A pipe m
serves to convey the steam required for heating purposes to the double casings
around the stills from which casings the condensed water runs out through the pipe j.
I have shewn in Figure 3 another modification of the apparatus, in which the
air loaded with vapour instead of passing directly from the hop still g into the cold
air chamber a as described with reference to Figure 2, enters first a serpentine
pipe & arranged inside a hollow cylinder C containing ice. In this manner the
condensation of the vapour is very rapid and the particles of essential vapour
which remain in suspension in the air after passing through the pipe 8 condense
finally within the receptacle a A cock fitted upon the pipe proceeding from the
hop still permits the separation of the latter from the condenser.
In this modification, the metal of the receptacle is provided with a double felt
or wooden casing which protects it from being heated by contact with the
outward air.
It will be understood that in this arrangement as in the preceding one the
cooling apparatus may be connected with one or more hop stills in order to
accelerate the operation of the apparatus.
It will be readily understood that the process above described for extracting
essential oil from hops is also applicable with the same advantages to other kinds
of vegetable substances from which it is desired to extract the essential liquids
contained therein.
The form and arrangement of the apparatus which permits this process to be
employed may be varied according to requirements and to the material treated;
without departing from the nature of this invention.
Having thus fully described the said invention as communicated to me by my
foreign Correspondent and the manner of performing the same I wish it understood
that I Claim:-
First The above described process of extracting by means of compressed air, the
essential oils contained in hops and other plants, the said process consisting
essentially in introducing a small quantity of steam into a vessel containing newly
dried hops or other vegetable substances for the purpose of bursting the cuticles
containing the essential oil, the said vessel being heated externally; introducing
into the vessel compressed air for absorbing or taking up the essential vapours
disengaged by heat; and connecting the vessel containing the air charged with
essential vapours with a receptacle in which a vacuum is formed, the connecting

page_text: pipe passing through a cooling apparatus which condenses the essential vapours and
converts them into a liquid state, the volatile liquid collecting at the bottom of the
said receptacle from whence it runs into a hermetically closed vessel.
Second. Utilizing the volume of air, which serves to convey the essential vapours
from the still to the receiver, during several operations for the purpose specified, an
air pump being employed which creates a vacuum in the receiver and at the same
time raises the pressure in the still in which the hops are placed, substantially as
set forth.
Third. The apparatus (substantially as described with reference to Figure 1 of
the accompanying drawings) comprising a still for containing the hops, and
provided with a double casing into which steam is introduced, a receiver in which
a vacuum may be formed, a cooling apparatus, and an air pump, all operating
substantially as set forth.
Fourth The apparatus (substantially as described with reference to Figure 2 of
the accompanying drawings) in which two stills and one air receiver are employed
in order to ensure a continuous action of the apparatus.
Fifth The utilization of the air receiver as a refrigerator or cooling apparatus,
the said receiver being provided with a double casing, in which cold water is caused
to circulate, and a central tube containing ice, substantially as described
Sixth The apparatus described with reference to Figure 3 of the accompanying
drawings in which apparatus the air charged with essential vapours before entering
the air receiver passes through a serpentine pipe surrounded by ice in order to
accelerate the condensation of the vapours.
In witness whereof I the said William Robert Lake have hereunto set my
hand and seal this Fifth day of April in the year of our Lord One thousand
eight hundred and eighty four.
WH PORT LATZE