Improvements relating to the Curing of Tobacco and Analogous Substances, and to Apparatus therefor.
Year: 1894

page_text: Date of Application, 14th Dec., 1894-Accepted, 26th Jan.,
1895
[Communicated from abroad by HENRY ALEXANDER WICKHAM, of Cooktown,
Queensland, Australia, Planter.]
Improvements relating to the Curing of Tobacco and Analogous
Substances, and to Apparatus therefor.
I, HAROLD NEILL, of 8 Canning Place, London, W., Merchant, 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:—
My invention relates to the curing of tobacco and analogous substances, and is
chiefly designed to provide for the manufacture of a superior class or grade of
tobacco than those produced by the methods or processes hitherto employed, whilst
obviating the risks and losses attendant on the curing of tobacco as heretofore
practised and also the necessity for employing skilled. and trained experts to carry
on or superintend the process.
To this end my said invention consists in an improved process and apparatus.
hereinafter described.
In my improved process of curing tobacco and analogous substances, instead of
allowing the substance to ferment in heaps or stacks in a shed or drying room, and
bulking and re-bulking the same as hitherto practised, I place the tobacco or other
substance in a closed box, vessel or chamber and cause it to undergo a slow.
fermentation therein, keeping it all the time subjected to pressure which is
continuously maintained by means of springs or their equivalents, and protecting it,
during the fermentation, against the action of the external atmosphere and other
external influences. A sweet aromatic fermentation of the said substance is thus
ensured, whilst putrefaction or putrefactive fermentation thereof is effectually
prevented, and the full aroma is retained in the substance and uniformly distributed
throughout the mass thereof.
In carrying my improved process into practice, I find it advantageous to subject
the tobacco or other substance, after the same has been harvested and partially.
dried, to a heavy pressure, sufficient not ouly to expel the greater part of the air
from the mass of the substance, but also to liberate from the cells thereof the juices
and essential oils contained therein, which are then free to permeate the whole mass;
the substance to be cured is then allowed to remain in the said box, vessel or
chamber until the curing or fermentation is completed, the pressure being.
continuously maintained during shrinkage of the mass.
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According to another modification of my improved process, I place the tobacco
in a closed box, vessel or chamber, and, after subjecting it to an initial pressure as
above described, I permit the access to the said substance of just the quantity of
air required for setting up and maintaining the sweet fermentation, whilst obviating.
the liability of the fermentation proceeding to the putrefactive stage by reason
of the admission of any further quantity of air during the process of curing. I allow
the substance to remain in such box, vessel or chamber until the said fermentation
is complete or practically complete, when the said substance is ready for further
manufacture into the various marketable forms thereof.
In some instances I make the aforesaid box, vessel or chamber in such a manner
that, when closed air-tight, it will contain sufficient air to initiate and maintain the
desired fermentation.
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In other instances 1 pile or, stack the tobacco in a box or chamber, and, after

page_text: starting the fermentation, I draw air out of the said box or chamber until the quantity
left therein is just sufficient to maintain a sweet fermentation without setting up a
putrefactive fermentation. Or I introduce into the said box or chamber carbonic
acid gas or other gas which will tend to resist or moderate the fermentation.
In the accompanying drawing :-
Figure 1 is a vertical central section, and
Figure 2 a plan showing one form of apparatus which may be advantageously
employed for carrying on my process.
A is a box or vessel open at the top and closed at the bottom. This box or
vessel is preferably constructed of wood and provided on the outside with iron
strengthening bands or straps B so as to enable it to withstand great internal
pressure, suitable packing-pieces C being arranged between the box A and the said
straps to provide a cylindrical exterior to the said box and thus facilitate the
handling thereof, as it can be easily rolled from place to place. The sides of the
box are preferably inclined so that the area of the base or bottom of the box is
slightly greater than that of the top thereof.
In the open end of the box A is fitted a piston or follower D, on which are
placed springs E; these springs bear at their upper end against a plate or frame F
which is held down in the upper part of the box A by cross-bars G. In order that
the position of the follower D. relatively to the plate or frame F, and therefore the
degree of compression of the springs E, may be readily ascertained while the box
or case is closed, I provide an indicator consisting of a graduated rod H attached
to the follower D and projecting through a hole in the plate or frame F; so that
the force exerted at any time may be roughly estimated by observing or measuring
the length of the portion of the rod H projecting beyond the frame F.
In carrying on my improved process with the aid of the apparatus just above
described, I place the tobacco-leaves or other substances to be cured in the box or
case A, the leaves being arranged one above another, in hands, or in any other
convenient manner, having regard to the form into which the tobacco is to be finally
prepared for consumption. Pressure is then applied by means of a hydraulic press
or otherwise so as to force the said leaves together and fill up the interstices
between them and at the same time expel most of the air and liberate the juices
and essential oils as above mentioned. More leaves are then inserted and pressure
again applied to the mass until the box or vessel A is filled to a proper height to
ensure the efficient operation of the springs E. The piston or follower D together
with the plate or frame F and springs E are then inserted, and sufficient pressure
is applied upon the said springs to permit the introduction of the cross-bars G,
which are then placed in position.
As the fermentation goes on and shrinkage of the mass gradually takes place, the
pressure is continuously maintained by the action of the springs E, which, by
pressing upon the piston or follower D, keep the leaves in a state of compression
and thus prevent the ingress of any undue amount of air into the mass and the
consequent setting up of a sour fermentation therein. Should the shrinkage
proceed to such an extent that the pressure exerted by the springs E, as indicated
by the rod H, is reduced to a lower degree than is desirable, the plate or frame F
is removed and a packing-piece or plate of suitable thickness inserted below the
piston or follower D. Or, if desired, the cross-bars G may be made taper and
adapted to bear against correspondingly inclined surfaces on the plate or frame F,
so that, by driving in the said cross-bars G, the plate or frame F may be moved
inward and the pressure on the mass increased. Or two or more sets of holes
may be provided for the reception of the said cross-bars, so that further pressure
can be applied upon the aforesaid springs, and the cross-bars then shifted to a
lower set of holes.
I find it advantageous to carry on the process above mentioned in a chamber or
space the temperature of which is between 60 and 80 degrees Fahrenheit, although,
in certain cases, a temperature of 90 degrees or more may be employed. The
rapidity of the curing process is decreased at lower temperatures, although the

page_text: quality of the product is not materially affected, so that, for economical working,
the boxes, vessels or chambers containing the tobacco under treatment should be
protected in cold weather or during other extremes of temperature.
The pressure to be applied will vary according to the dryness of the leaves
when placed in the box, vessel or chamber and to the character of the tobacco to
be produced, the pressure required in most cases being higher when the leaves are
dry and lower when they are moist. The essential points to be considered are,
that the pressure shall be sufficiently high to liberate or express the juices and
essential oils from the cells of the plant and thus allow the fermentation to
commence, and that the tobacco shall be protected against external atmospheric
influences during the curing process. Care should be taken, however, that, when
the leaves are moist, the pressure applied is not too great, as, in this case, the
essential oils and other juices will be squeezed out of the mass and loss of weight
in the finished product will result.
If desired, I insert in the said box, vessel or chamber a small quantity of already
fermented tobacco for the purpose of initiating the fermentation.
The time taken by the process above described varies from about two months
to six or seven months according to the temperature of the space in which the
curing boxes or vessels are stored, and other circumstances. The tobacco may,
however, be very advantageously left in the said boxes, vessels or chambers for a
year or more, as the quality and aroma of the tobacco continues to improve,
somewhat after the manner of wine which is allowed to mature for several years.
Other suitable means may, if desired, be employed for maintaining the pressure
on the tobacco in the box, vessel or chamber as shrinkage takes place; for
example, the piston or follower D may be in connection through a rod or the like
with a hydraulic or other fluid-pressure cylinder in which the desired pressure is
constantly maintained by means of a hydraulic accumulator or otherwise; or, if
desired, suitable arrangements of weights may be employed for this purpose.
It is obvious, moreover, that vessels constructed of or lined with metal which
will not be attacked by the vegetable juices and the like, may be employed in lieu
of the wooden boxes or vessels above described.
I sometimes compress the tobacco-leaves, after they have been harvested and
partially dried, into a suitable box or vessel substantially as above described, but
instead of maintaining a continuous pressure thereon, I close the said box or vessel
in such a manner as to prevent access to the tobacco of more air than is actually
required to set up and maintain the desired fermentation. The fermentation may
be said to be practically complete in from two to six months according to the
temperature of the surroundings, and other circumstances; the tobacco will then
have developed a peculiar sweet aromatic odour and will be ready for further
manufacture as desired.
In some instances I make the aforesaid box or vessel in such a manner that,
when closed air-tight, it will contain sufficient air to initiate and maintain the
desired fermentation. If desired, I insert in this air-tight box or vessel a small
quantity of already fermented tobacco for the purpose of initiating the
fermentation.
In other instances I pile or stack the tobacco in a box or chamber, and, after
starting the fermentation, I draw air out of the said box or chamber until the
quantity left therein is just sufficient to maintain a sweet fermentation without
setting up a putrefactive fermentation. Or I introduce into the said box or
chamber carbonic acid gas or other gas which will tend to resist or moderate
the fermentation.
My improved process can, if desired, be commenced at the tobacco-fields and
go on whilst the tobacco is in transit on board ship or otherwise, the said
process being completed either on the way or at the place of destination, thus
saving a considerable amount of time.
My improved process may, moreover, be applied to the curing of other natural
products, such for instance as tea, in which a sweet fermentation takes place.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
First. The curing of tobacco and analogous substances by a process in which
the substance to be cured is caused to undergo a slow fermentation whilst subjected
to a pressure which is continuously maintained throughout the curing process
notwithstanding shrinkage of the mass, substantially as hereinbefore described.
Second. The herein described process of curing tobacco and analogous
substances, which process consists essentially in causing such substance to
undergo a slow fermentation in a closed box, vessel or chamber, in which,
throughout the curing process, it is subjected to a continuously maintained pressure
and is protected against external atmospheric influences.
Third. The improved process of curing tobacco and analogous substances, in
which process the substance to be cured is placed in a closed box, vessel or
chamber and subjected to an initial pressure to expel the greater quantity of the air
from the mass of the said substance and liberate the juices and essential oils from
the cells, and then to a pressure which is continuously maintained throughout the
curing process notwithstanding shrinkage of the mass, substantially as, and for the
purposes, herein before described.
Fourth. The modification of my process in which I place the substance to be
cured in a closed box, vessel or chamber, and subject it therein to the action of
atmospheric air in such quantity as to ensure a sweet fermentation of the said
substance, whilst protecting it against external atmospheric influences, and thus
preventing any putrefactive fermentation thereof, substantially as described.
Fifth. The modification of my process in which I compress the substance to be
cured in a closed box, vessel or chamber so as to expel the greater part of the air
from the mass thereof and liberate from the cells the juices and essential oils
contained in them, and then allow the said substance to remain in the said box,
vessel or chamber subject to the action of atinospheric air in sufficient quantity to
set up and maintain a sweet fermentation whilst preventing any putrefactive
fermentation of the said substance, substantially as described.
Sixth. The combination, with a box, vessel or chamber, of a piston or follower
therein, a removable plate or frame, springs arranged between the said piston or
follower and the plate or frame, and means for holding the said frame in position
in the said box vessel or chamber, substantially as, and for the purposes, specified.
Seventh. The combination, with a box, vessel or chamber, of a piston or follower
therein, a removable plate or frame, springs between the said piston or follower
and the plate or frame, means for holding down the said plate or frame, and a rod
or index attached to the said piston or follower and projecting through the said
plate or frame and movable with the said piston or follower, substantially as, and
for the purposes, specified.
Dated the 14th day of December 1894.
D. YOUNG & Co.,
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.