Improvements in Baking Powders and like Preparations.
Year: 1890

page_text: COMPLETE
SPECIFICATION.
Improvements in Baking Powders and like Preparations.
I BENJAMIN WILLCOX of 47 Lincoln's Inn Fields in the County of Middlesex Patent
Agent do hereby declare the nature of this invention which has been communicated
to me from abroad by The Rumford Chemical Works a Corporation organized under
the laws of the State of Rhode Island' and having its principal place of business in
the City of Providence in the said State 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 reference to preparations such as are known as baking powders,
in which the active constituents are a dry acid or acid salt and a carbonate, or their
equivalents, between which reaction takes place in the operation of mixing dough,
resulting in the liberation of carbonic acid gas, as is well understood.
It is customary in the preparation of baking powders to introduce a certain pro-
portion of an inert substance, as starch, flour or other dry powder. The chief utility
of this inert substance is that of a separator of the active ingredients, to prevent
reaction between them under the influence of ordinary atmospheric humidity and it
also serves as a diluent to reduce the strength of the baking powder to the commercial
standard. Corn starch is the substance commonly used for this purpose, and may be
taken as the typical diluent in considering the changes that occur in baking powders
under the conditions to which they are ordinary exposed.
It is a well known fact that baking powders deteriorate, or suffer loss of strength
to a greater or less degree. This does not take place to an appreciable extent so long
as the powder is in a tightly closed package which properly excludes the atmosphere,
the deterioration advances more or less rapidly when the powder is exposed to the
influence of the atmosphere. It is of course desirable, for the sake of economy, to
obviate tlie necessity for using such packages. The loss of strength or capacity is the
consequence of a premature re-action between the acid and the carbonate, and the
liberation of the carbonic acid gas which should be released only in the dough itself;
and the obvious conclusion is that the character of the diluent or separator has much
to do with the permanence of the baking powder.
Corn starch in its ordinary commercial condition contains from twelve to fourteen
per cent. of moisture and when dried and afterwards exposed to the atmosphere, it
will re-absorb this normal amount. It has moreover, the property of readily parting
with its moisture to deliquescent bodies, and when in admixture with deliquescent
salts and exposed to air it acts as a sponge, absorbing the moisture from the air and
parting with it to the salt with which it is mixed. Thus under conditions of ordinary
occurrence the utility of the starch as a separator or protector is inpaired, and it
virtually becomes a conductor of moisture to the salts in admixture with it, with the
result herein before mentioned.
The attempt has been made to prevent the detrimental action following exposure
to humidity by adding to the mixture in one way or another, an oleaginous or fatty
material such as lard; stearine; tallow or paraffine but without satisfactory results.
When solid fats are employed in quantity' sufficient to constitute an efficient pro-
tection, amongst other objectionable effects the bread prepared therewith is spotted
from the local action of the acid and soda particles. Moreover, "caking" is likely
to result when powders' so prepared are exposed to the ordinary maximum temperature
and then cooled.
The object of the present invention is to prevent the deterioration which occurs
when baking powders as; ordinarily, prepared: are exposed to varying' atinospheric

page_text: comitions, and to produce a permanent or stable mixture, by substituting for the starch
wholly or in part; a material which, while efficient as a separator and whose presence
in a food product is entirely unobjectionable, does not act like starch in absorbing
moisture and parting with it to the active constituents of the powder. This result
accomplished according to this invention by the use of a salt of a fat acid such as a
stearate.
As an example of one mode of carrying the invention into effect I give a descrip-
tion of the procedure followed with stearate of calcium by the aid of which the objects
of the invention are realized.
56 parts of lime are slacked and made up into a thin milk with say 2000 parts of
water, and into this are stirred 568 parts of commercial stearic acid reduced to a coarse
powder by grating. These substances, after being thoroughly commingled by stirring
while cold, are heated to rapid ebullition and so maintained until neither the mass nor
the liquid gives an alkaline re-action with litmus paper. The granular product that
separates from the liquid on cooling down somewhat is taken out, drained and dried.
In this condition it forms a soft floculent mass which is reduced to the condition of a
fine powder and is added to the acid and carbonate of the baking powder. In intro-
ducing it into the baking powder it is preferable to mix a portion of the powdered
stearate and the acid and then to mix the other portion of the powdered stearate and
the carbonate afterwards mixing together these two mixtures with or without a further
addition of diluent. The mixing may be effected by stirring and sifting, milling, or
grinding, or by any other suitable means.
The combination of stearate with an acid and also of a stearate with soda may be of
value as separate articles of commerce for other purposes than as ingredients of a
baking powder. The bi-carbonate of soda of commerce and various dry acids are
largely sold for separate use for domestic and other purposes. The soda and some of
the acids, by the absorption of moisture from the air, often become lumpy or caked,
which impairs their usefulness, unless they are finely crushed before using. It is
inconvenient and sometimes impracticable for the consumer to reduce such material to
the required degree of fineness so as to obtain the best results in their use.
admixture of the stearate with the acid and soda will prevent the absorption of
The
atmospheric moisture, and thereby preserve the material in a finely powdered
condition.
.
It will of course be understood that the mode of procedure given above may be
modified in many ways without departing from the spirit of the invention, which is
not limited to the use of stearate of calcium, and that the use in a baking powder
of any salt or combination of a fat acid with an inorganic base, is within the
invention.
It shall be understood, however that tartaric, citric, and lactic acids are not included
in the invention. These acids, though they are assigned to the fatty group, are not
in the strict senso fatty acids. The invention includes only the higher members of
the fatty acid group, namely those derived from-fats themselves, and herein termed
"fat acids."
While the new diluent is designed to be used in place of the starch or other diluents
commonly employed, a useful result and one within the invention, may be obtained
by replacing a portion only of the starch ordinarily employed with the stearic or other
fatty acid salt, or compound.
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. A baking powder, or like preparation containing a salt or combination of a fat
acid with an inorganic base, substantially as herein before described.
2. A baking powder or like preparation containing as active constituents an acid
and a carbonate, or their equivalents, combined with a salt or combination of a fat
acid with an inorganic base, substantially as hereinbefore described.
.5
5

page_text: 3. A baking powder or like preparation containing as a diluent the stearate of an
alkaline earth, such as stearate of calcium, substantially as hereinbefore described.
Dated this 28th day of October 1890
J. H. JOHNSON & Co.,
Agents.