Improvements relating to the Treatment of Tea.
Year: 1892

page_text: Date of Application, 6th May, 1892
Complete Specification Left. 6th Feb., 1893-Accepted. 1st Apr., 1893
PROVISIONAL SPECIFICATION..
Improvements relating to the Treatment of Tea.
1, HENRY CARUS-WILSON, of 22 Fenchurch Street, in the City of London,
Merchant, do hereby declare the nature of this invention to be as follows :-
My invention relates to the treatment of tea and is designed to provide means
whereby the volatile oils and essences contained therein will be much more com-
pletely utilized and developed than has hitherto been the case, thus imparting to
the infusion a much finer aroma and consequently enhancing the market value of
the tea besides affording other advantages hereinafter more particularly set forth.
It is well known that the distinctive flavour of tea to which in great part it owes
its value is due to the volatile oils it contains. In the present system of manu-
facture of a large class of teas, especially those of Indian growth, the development
of these volatile oils is to a great extent a matter of chance depending upon
atmospheric and other conditions at the time of manufacture and the whole
contents of the leaf are not developed to their utmost extent so as to turn them to
the best possible account; the manufacture cannot therefore be considered com-
plete. By the present invention I remedy this defect and provide a process which
taking place subsequent to the ordinary treatment to which the tea is now subjected
in tea growing countries, completes the manufacture.
My invention consists essentially in impregnating the tea at any suitable time of
manufacture and in any convenient manner with borax either in solution or as
powder. This may be conveniently effected by a machine hereinafter more fully.
described and in the manner following, that is to say, the tea is caused to rotate in
a machine into which a solution of borax is introduced by a fine jet in such a way
that the tea is very gradually saturated without being over-wetted. The solution.
is applied at a temperature just below boiling point and from 3% to 5% by weight
of borax forms a very suitable mixture. Whilst the tea is still in the cylinder a jet
of steam is introduced and the rotation of the cylinder is allowed to continue for
about half an hour.
The tea is then taken from the cylinder and spread out in thin layers on specially
constructed trays composed of an open mesh so that the air may have free access..
This first drying in the air, is allowed to continue for about 12 hours.
The tea is then dried on a suitable tea-kiln by means of a steady current of hot
air passing through the tea from underneath at a low temperature, say 125° to.
150° Fahrenheit.
The machine which I prefer to use resembles an ordinary tea mixer in general
design and is provided with suitable deflectors, its interior being preferably lined;
with enamelled iron. The borax distributing jet is introduced by a hollow trunnion
on one side and the mouth of the said jet is so arranged that it gradually saturates.
with finely divided particles the whole of the tea as it rotates in the cylinder-so
that the solution is gradually absorbed by the leaf without over-wetting it. The
jet is worked by means of a pump exterior to but connected to the cylinder so that
the same will be in action only whilst the cylinder rotates. By another hollow
trunnion on the opposite side a jet of steam is introduced into the cylinder when
necessary the object being to maintain the temperature of the tea whilst it is.
rotating after the treatment with the solution..
By my process the usefulness of the tea from the consumers point of view, and
also its intrinsic market value are greatly increased. Besides this the tea treated
by my improved process may be kept for a much longer time than heretofore without
deterioration in value due to the dispersion of the volatile oils which in certain teas
is very considerable.

page_text: Although I have herein described a machine which is very suitable for the
purpose of carrying out my invention, I wish it to be understood that I may use
other machines differing considerably in detail without departing from the nature
of my invention.
Dated this 6th day of May 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements relating to the Treatment of Tea.
I, HENRY CARUS-WILSON, of 22 Fenchurch Street, in the City of London,
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 treatment of tea, and is designed to provide means
whereby the useful volatile oils and essences contained therein will be much more
completely utilized and developed than has hitherto usually been the case, thus
imparting to the infusion a much finer aroma and consequently enhancing the
market value of the tea, besides affording other advantages hereinafter more
particularly set forth.
It is well known that the distinctive flavour of tea, to which, in great part,
it owes its value, is due to the volatile oils it contains. In the present system
of manufacture of a large class of teas, especially those of Indian growth, the
developement of these volatile oils is to a great extent a matter of chance,
depending upon atmospheric and other conditions at the time of manufacture,
and the whole contents of the leaf are not developed to the utmost extent so
as to turn them to the best possible account; the manufacture, therefore, cannot
in such case be considered complete. By the present invention I remedy this
defect and provide a process which can be applied with or after the ordinary
treatment to which the tea is now subjected in tea-growing countries, and which
successfully completes the manufacture.
My invention is especially applicable to those qualities of teas which are
found or known to contain a high percentage of tannin, or to have been not
sufficiently fermented in the preliminary stage of manufacture, and it consists in
treating the tea at any suitable time of manufacture, and in a suitable manner,
with borax, either in solution or in the form of powder. This may be con-
veniently effected by the apparatus hereinafter more fully described, and in the
manner following, which may be taken as an instance of a good mode of
treating the tea leaf with borax according to my invention.
The tea is agitated in a cylinder, into which a solution of borax is introduced
by a fine jet in such a way that the tea is very gradually saturated without
being over-wetted. The solution is applied at a temperature a little below
212° Fahrenheit, and from 3% to 5% by weight of the borax to the tea
treated, forms a suitable proportion for mixture. It is obvious it will be found
in practice that the proportions used should be in some cases varied according
to the character of the tea treated; for instance it is found that for certain
classes of tea, and particularly for tea of China growth, about 2% by weight of
borax may be used with advantage. Whilst the tea is still in the cylinder, a jet
of steam is introduced and the agitation of the contents of the cylinder, by its
rotation or otherwise, is allowed to continue for a suitable time so as to effect a
proper impregnation of the tea; this will usually be effected in about half an
hour.
In some cases, especially where the class of tea is found to require very
complete impregnation and the process is required to be hastened, I find it very
advantageous that the steam introduced into the cylinder should be maintained

page_text: and-made to act as high pressure steam, so as to cause a more energetic and com-
plete impregnation of the tea. The cylinder should be a suitably constructed
closed cylinder, as ordinarily made for like purposes, and the pressures and
duration of operation should be regulated according to the class of tea treated, and
the result sought to be attained.
By the employment of steam as above directed it will be found that the tempera-
ture of the tea is properly maintained, and, moreover, steam employed under
pressure materially assists the borax to penetrate the leaf.
8
As an alternative to the use of borax in solution, I take borax in the form of
powder and in about such proportions as are hereinbefore stated, and I mix the
said powder by any suitable means, as, for instance, by means of an ordinary tea-
mixer, with a quantity of dry or of moistened tea leaf, in such a manner that the
powdered borax is very uniformly distributed throughout the mass of tea. It is
then while in intimate contact with the borax, agitated in a receptacle into which
a jet of steam is delivered, or agitated in a receptacle charged with steam under
pressure, as in the instances hereinbefore given of modes of treatment in which
borax is employed in solution, the temperature of the contents of the receptacle
being maintained by the said steam at a temperature of about 212° Fahrenheit, or
at a higher temperature, during the said agitation, as may be suitable according to
the quality and condition of the tea treated.
The tea after treatment in the cylinder in the manner hereinbefore explained is
taken therefrom, and spread out in thin layers on suitably constructed trays
composed of an open mesh so that air may have free access thereto and so that the
component elements of the tea leaf may have time to develop or adjust themselves.
This operation is allowed to continue for say, about 12 hours.
The tea is then dried in a suitable tea-kiln or like apparatus by means of a
steady current of hot air passed through the tea from underneath the aforesaid
trays at a low temperature, say from 100° or thereabouts, to 150° Fahrenheit.
The apparatus which I prefer to use for agitating the tea resembles an ordinary
tea mixer in general design, and is provided with suitable deflectors, its interior
being preferably lined with enamelled iron. When a borax-distributing jet is
employed it may be advantageously introduced by a hollow trunnion on one side,
and the mouth of the said jet is provided with a rose or with a spreader or is
otherwise so arranged that it causes the solution to issue in the form of a fine spray
which gradually saturates the whole of the tea as it is turned over in the cylinder,
so that the solution is gradually absorbed by the leaf, without over-wetting the
same. The said jet is injected by means of a pump exterior to but connected with
the cylinder, so that the jet may be made to act whilst the cylinder rotates. By
another hollow trunnion on the opposite side, the above-mentioned jet or other
supply of steam is introduced into the cylinder when necessary.
By my process the usefulness of the tea from the consumer's point of view, and
its character, is improved, and its intrinsic market value greatly increased. High
qualities of tea can be manufactured and supplied to the consumer at less cost than
hitherto, and further, tea treated by my improved process may be kept for a much
longer time than heretofore without such deterioration in value as would under
ordinary circumstances result from the dispersion of the volatile oils, which in
certain teas is very considerable.
Although have herein described apparatus which is very suitable for the
purpose of carrying out my invention, I wish it to be understood that other
apparatus differing considerably therefrom in detail may be employed without
departing from the nature of my invention.
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 :-
1. The treatment of tea with borax, substantially as herein before described, for
the purposes snecified.

page_text: 2. The process of treating tea so as to effect its gradual and necessary impreg
nation with borax, and its subsequent treatment, all substantially as hereinbefore
described, for the purposes specified.
3. The improved product consisting of tea of an improved character produced
by the treatment of the leaf with borax substantially as herein described.
Dated this 6th day of February 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.