Decoctions of Tea, Coffee, and Cocoa.
Year: 1885

page_text: Decoctions of Tea, Coffee, and Cocoa.
I, SAMUEL CLELAND DAVIDSON of Queensbridge Street Belfast in the County
of Antrim Ireland, Merchant, do hereby declare the nature of my invention for
IMPROVEMENTS IN THE MANUFACTURE OF AQUEOUS INFUSIONS OR DECOCTIONS OF
TEA, COFFEE AND COCOA to be as follows:-
J
When aqueous infusions or decoctions of tea, coffee or cocoa are prepared in the
ordinary way, they are naturally very prone to decomposition and turbidity if
kept even for a few days only, and I have found that the addition to them of
antiseptics such as salicylic acid or bisulphite of lime does not prevent but on the
contrary accelerates this decomposition.
Now the object of my invention is to manufacture aqueous infusions or
decoctions of tea, coffee and cocoa which will keep a long if not an indefinite time
free from decomposition and turbidity and be suitable for use as beverages at any
time either alone or in combination with hot or cold water or with carbonated
water.
The invention consists in treating the infusions or decoctions with an alkali or
an alkaline substance preferably borax (biborate of soda) or carbonate of soda by
adding it until the more or less acid condition which the infusions ordinarily
show to test paper is counteracted and a visible alkaline reaction to test paper is
established. This treatment preserves these infusions so that they will keep like
wine if bottled like it or they may be bottled as aërated beverages in combination
with carbonated water. In this latter case however the infusions (especially of
tea) should undergo a preliminary clarification as otherwise the action of the
carbonated water subsequently develops an objectionable turbidity.
The clarification process which I preferably adopt is that employing trihydrate
of alumina and described in the specifications of several former Letters Patent
granted to me and numbered respectively 361, 362 and 3049 of 1880 and which
Specifications are hereinafter referred to as
my previous specifications."
"
I preferably use the trihydrate of alumina in the hot infusion and filter it out
again by straining through bag filters while the infusions are still hot as I find
the resulting liquors are stronger than when the alumina is added to the cold
infusions as recommended in my previous specifications. The condition in which
... nll

page_text: I preferably use the trihydrate of alumina is when blended with water to the
consistency of thick cream and of this I use about one gallon to 20 gallons of
infusion, the infusions being about 3 or 4 times the strength of the ordinary
beverages of tea, coffee and cocoa.
When borax is the alkaline substance used for preserving the infusions, this
clarification process should be completed and the infusion allowed to cool before
the borax is added, and although on becoming cold the infusion usually gets turbid,
nevertheless the alumina has, on being filtered out, taken with it the deleterious
matter requiring removal and the turbidity referred to is quickly dissipated on
addition of the borax and the infusion will then bear admixture with carbonated
water without the turbidity reforming.
If however carbonate of soda be used as the alkaline substance for preserving
the infusions I preferably add it to the hot infusion either before or after the
alumina as may be most convenient, and the infusion can be filtered free of the
alumina either while hot or when cold.
As regards infusions or decoctions of coffee and cocoa the clarification, although
it improves their brilliancy of appearance, is not a necessity, for with the alkaline
treatment alone they will bear admixture with carbonated water and remain free
from any subsequent development of turbidity.
If the alkali be added to these infusions when cold it will usually precipitate a
certain amount of solid matter-which can however be readily removed by filtration
or decantation.
The water best suited for making the infusions or decoctions is what is known
as "soft water," that is to say, water free from the hardness of sulphate of lime in
solution.
If the infusions or decoctions be required sweetened I preferably add the sugar
to the boiling water before the infusions are made; but the amount of sugar to
use is entirely a matter of taste as its presence or absence does not materially
affect the operation of the hereinbefore described treatment of the infusions.

page_text: Improvements' in the Manufacture of Aqueous Infusions or
Decoctions of Tea, Coffee, and Cocoa.
I SAMUEL CLELAND DAVIDSON, of Queensbridge Street, Belfast, in the County
of Antrim, Ireland, 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:—
When aqueous infusions or decoctions of tea, coffee or cocoa, as ordinarily
prepared, become cold they are usually more or less turbid in appearance, and in
this state are very prone to decomposition if kept for even a few days and I
have found that the addition to them of antiseptics such as salicylic acid or
bisulphide of lime does not prevent but on the contrary rather accelerates their
decomposition.
Now the object of my invention is to manufacture aqueous infusions or decoctions
of tea, coffee and cocoa, which will keep a long, if not an indefinite, time free from
decomposition and turbidity and be suitable for use as beverages at any time either.
alone or in combination with hot or cold water or with carbonated water.
The invention consists in treating the infusions or decoctions with an alkali or
alkaline substance (preferably biborate of soda or carbonate of soda) by adding
same until the more or less acid condition which the infusions ordinarily show
to test paper is counteracted and a slightly alkaline reaction is established.
This treatment with alkali causes the clarification of the infusions or decoctions.
In the coffee and cocoa infusions it acts by precipitating the turbid matter but in
the tea infusions by dissolving it. As the action by which the alkali effects the
clarification of the coffee and cocoa infusions is therefore different from that by
which it effects the clarification of the tea, I will describe the process relating to
the coffee and cocoa separately from that relating to the tea infusions.
My improvements in the manufacture of coffee and cocoa infusions are carried
out as follows:-I make an infusion or decoction of coffee and cocoa with boiling
water of preferably three or four times the strength that such infusions are ordi-
narily used as beverages, and for convenience of operation, I strain off the liquor
from the grounds. The strained liquor is usually more or less turbid in appearance
and shews a slightly acid reaction to test paper. I then add to it an alkali or
alkaline substance preferably biborate of soda in sufficient quantity to render the
liquor slightly alkaline to test paper and the result of this treatment is that the
matter causing the turbid appearance of the infusion will soon form into a
flocculent precipitate which will gradually settle to the bottom, leaving the
liquor above it quite free from turbidity and rather richer in color than before
this treatment. This result is produced by the alkali whether the infusions be
hot or cold when it is added, but its action is slower in the cold infusions. The
precipitated matter can then be removed either by decantation or by any con-.
venient method of filtration such as by straining through cloth filter bags, and
when the liquors. are freed from this precipitated matter their treatment is complete,
and they are now capable of being kept a long time if bottled and securely corked
1100 2

page_text: so as to exclude the air, or they may be bottled in combination with carbonated
water to form aërated and sparkling beverages.
My improvements in the manufacture of tea infusions are carried out as
follows I make an infusion or decoction of tea with boiling water, and of pre-
ferably three or four times the strength that such is ordinarily used as a beverage,
and strain it free from the leaves and sediment. The liquor at this stage and while
bot is brilliantly transparent, but on cooling it gets very opaque and turbid owing
to a precipitation of the constituent ingredients of the infusion, due to their chemical
reaction upon one another.
To this opaque looking liquor I now add an alkali or alkaline substance, pre-
ferably biborate of soda in sufficient quantity to dissolve the precipitated matter
and to produce a slight reaction to test paper, and when so treated the infusion is
capable of being kept a long time in good condition and without becoming turbid
again if bottled carefully so as to exclude the air, and may be used as a beverage
at any time either alone or in combination with hot or cold water, or with car-
bonated water provided the carbonated water is only added to it a short time
before using; but when bottled with carbonated water under pressure to form an
aërated and sparkling beverage the alkali treatment alone is not sufficient to
prevent a slight reprecipitation and turbidity forming again under the action of the
carbonic acid, and to prevent this result I treat the infusion with trihydrate of
alumina prior to its treatment with the alkali.
I employ and prepare the trihydrate of alumina in the same manner as described
in the Specifications of previous Letters Patent granted to me and numbered
respectively 361, 362 and 3049 of 1880, but in the present instance I preferably
add to the trihydrate of alumina to the hot infusion and filter it out again by
straining through bag filters while the infusion is still hot as I find the resulting
liquor is stronger than when the alumina is added to the cold infusion as recom-
mended in my previous specifications referred to.
The condition in which I preferably use the trihydrate of alumina is when
blended with water to the consistency of thick cream and of this creamy paste I use
about one gallon to each 20 gallons of infusion. The alumina combines with and
removes, on being filtered out, the matter which the carbonic acid would otherwise
subsequently precipitate.
The filtered infusion on cooling will however become almost as turbid as if it
had not been subjected to the alumina treatment but on adding the biborate of
soda this turbidity is entirely dissolved and the liquor thereby thoroughly clarified
and the infusion as now prepared will bear admixture under pressure and bottled
with carbonated water, without any turbidity reforming; and will remain in good
condition a long time and form an agreeable drink having the flavour and other
characteristic properties of tea combined with the attractive appearance of a bright
and sparkling beverage.
The amount of alkali or alkaline substance requisite to produce the results herein-
before described is usually, in the case of biborate of soda or carbonate of soda,
about 1 to 2 grains to the fluid ounce of infusion when prepared to the strength
hereinbefore recommended..
If the infusions or decoctions of either tea, coffee or cocoa be required sweet,
sugar may be added to the clarified liquors to whatever degree of sweetness may
be desired, care being observed that the sugar used is of the purest quality.
The water which I preferably use in the preparation of all the above mentioned
infusions or decoctions is what is known as "soft water," that is-water free from
the "hardness" of sulphate of lime in solution.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The clarification' of aqueous infusions or decoctions of coffee or cocoa so that
thaill unmain alosified and in mand audition a long time if full- hottled an

page_text: as to exclude the air and bear admixture with carbonated water under pressure,
without subsequently becoming turbid again under the action of the carbonic acid,
by treating them with an alkali or alkaline substance until a faintly alkaline action
to test paper is established whereby the turbid matter held in partial solution or
existing therein is precipitated from the liquor in a form capable of being removed
by decantation or filtration all substantially as herein before described.
2. The clarification of aqueous infusions or decoctions of tea so that they will
remain clarified and in good condition a long time, if carefully bottled and the air
excluded, by treating them with an alkali or alkaline substance, and thereby dis-
solving and holding in solution the matter causing their turbidity all substantially
as hereinbefore described.
3. The clarification of aqueous infusions or decoctions of tea so that they will
bear admixture with carbonated water under pressure and remain in good condition
without subsequently becoming turbid again under the action of the carbonic acid;
by the combined treatment of same with trihydrate of alumina and an alkali or
alkaline substance all substantially as herein before described.
J. C. MEWBURN,
Agent.