in Ovens therefor. NEW AND USEFUL IMPROVEMENTS IN THE PROCESS OF BREAD RAISING AND BAKING AND IN OVENS THEREFOR and
Year: 1887

page_text: in Ovens therefor.
To all whom it may concern: Be it known that I THOMAS RICKETT of Southampton,
Hants, Mechanical Engineer have made CERTAIN NEW AND USEFUL IMPROVEMENTS IN
THE PROCESS OF BREAD RAISING AND BAKING AND IN OVENS THEREFOR and I 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 5
Baking as commonly performed is conducted in ovens made and managed with
reference only to heat and with no necessity for being air-tight.
My improved process of baking requires in the oven an establishment of the
following conditions to wit: 1st that the Oven shall be air-tight, 2d that the air-tight
oven shall have its atmosphere reduced to a pressure less than that of the external
air. 3 that the air-tight vacuum oven shall be connected with a condenser to draw
away its steam and 4th these conditions require to be all in combination with the
proper mechanical arrangements necessary for producing and maintaining in the oven
the necessary degree of heat required for baking.
The object of my invention is to produce good bread (and under the term bread I
include cake pastry &c.) without that strict attention to previous raising of the dough
required by the ordinary oven and without the same necessity for materials as lard
butter &c. to produce shortness that is required by the ordinary oven.
Under the oven conditions I have enumerated dough made of simple flour and
water only or seasoned with the ordinary substances made use of for such purposes,
as salt, sugar, soda &c. will without the addition of raising powders yeast, or any
artificial incans for raising, become baked into good wholesome and light bread
superior to most, and equal to the best of ordinary fermented breads: while doughs
made with raising materials of any kind may be made with vastly less, and with
equal effect when baked in an oven provided with the conditions I bave herein set
forth a peculiar shortness without shortening being produced in the bread when
baked by my new process.

page_text: MODE OF OBTAINING THE REQUIRED CONDITIONS.
I will first describe the means I employ to obtain the conditions needed in order to
carry out my new Process-baking.
To distinguish my improved oven from the ordinary one, I call it the vacuum oven:
which oven I will now proceed to describe.
On the sheet of drawings hereto annexed and making part of this specification,
Figure 1 is a side section shewing an oven of rectangular shape.
Figure 2 is a cross section, Figure 3 represents the door of the oven, Figure 4,
represents the condensing apparatus.
The oven is made of either cast or plate iron, when of cast it is made of one pieco
with an open end for the door. A indicates the oven, B the apparatus for exhausting
he air, the steam condenser, D the oven door, E the firebox, F Steam Jet, G steam
poiler.
a is an air-pipe connection between the steam jet F, and the air tight chest b, which
air connection continues through the coiled pipe c in the steam condenser C, to the
bent short air pipe d, which terminates in the top of the oven A.
The door D is shewn in position on Fig. 1, and closed, the letter e indicating the
vulcanized india rubber cushion which makes the joint air-tight.
This metal oven is set in brickwork indicated by the letters ff, E indicates the
fire-box under the oven the grate-hars: h h indicate the hot air flues that carry the
heat around the oven: .. is a bed of firebrick under the oven bottom to protect it
against the sudden heat: j.j. are screw-nuts on the door for tightening where the
door is shut against the rubber cushion, the steam boiler G, is set in brickwork
indicated by k, k.
Figure 5 is an enlarged view of the steam vacuum jet F to more clearly illustrate
its operation. m is an internal pipe through which steam from the boiler G, passes or
rushes when the exhaust is to be produced, n is a sleeve or shroud that encases m, () is
the funnel shaped end of the sleeve or shroud n: it is made separately and screwed on
as indicated, this funnel is made of copper or thin metal and thickened at r, r, by an
addition in which to make the screw: a counter screw thread is made in the sleeve n,
at this point and the funnel thus connected with it.
The steam pipe m from the point indicated by x-x to its termination in the funnel o,
is tapered down to a knife edge, causing a gradual enlargement of the surrounding
air-space until the point . z. is reached.
The branch pipe p, opens into the sleeve at or near the point where the steam
pipe m begins to taper, and connects the inside air of the oven with the air space in
the sleeve around the steam pipe m. The proportions and connection between the
steam pipe m and sleeve, are so shaped and arranged as to prevent all tendency of the
steam from entering the air space of the sleeve in its rush from the boiler into
the funnel and thence into the open air, as a consequence of this the air of the oven
must be sucked or drawn out in proportion to the vacuum produced in the funnel and
shroud by the tenuity and force of the rushing steam.
EXPLANATION OF THE MECHANICAL ACTION OF THE OVEN AT WORK.
The dough to be baked having been placed in the oven and the door closed, the screw
nuts are turned until the door is pressed against the india rubber seat. The exhaust
apparatus is now set to work until a vacuum of from ten to twelve pounds per square
inch is produced when the dough which in part has obtained a temperature of about
110 degrees will begin to rise and so continue until it has attained a temperature of
about 140 at which point or near it, it loses elasticity becomes short plastic and putty
like, and incapable of further expansion, as the process of baking goes on steam rises,
and so long as the exhaust is kept up, passes out through the air-pipe from the top
of the oven into the coil of the condenser C, where it condenses and runs out into
the air-tight chest b under the condenser.
I prefer to continue the vacuum only until the bread is set: or for about half to
two thirds of the time required in the oven. When the action of the exhaust

page_text: apparatus is stopped the steam which rises from the bread will gradually reduce the
vacuum to zero, as this steam is not wanted in the oven a valve is provided for its
escape, the external pressure of the atmosphere becoming now balanced by that
within the oven the door may be freely opened at any time for examination of
the bread.
PHILOSOPHY OF THE VACUUM OVEN.
By the ordinary bread making processes the water of the dough is not converted
into steam at a less temperature than 212 degrees such steam cannot therefore do
anything towards making the dough light and short because dough at about 140 and
beyond becomes incapable of forming the air-cells on which lightness depends.
In my new process of bread-making because of the lessened atmospheric pressure
within the vacuum oven I am able to obtain the raising or leavening quality and
power of steam at low tension, the water in the dough beginning to be converted into
vapor on the temperature of the dough becoming about 110 degrees: water
theoretically in a perfect vacuum boiling at 70 degrees.
It thus happens in my improved process that extraneous or artificial means for
raising the dough have less work to perform and may consequently be used in smaller
quantities than where the baking is done in the ordinary way-this not only works
economy of materials but it also saves time and likewise introduces an element of
precision and certainty with method and order unknown to the common modes in use.
Leavened bread baked by my process is light without bitterness and short and
tender without shortening materials, while in breads made with raising powder so
small a quantity is needed in comparison with ordinary use as to become unobjectionable
on the score of health and taste."
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.
1st. In the process of bread making, the raising and baking of the dough in an
air-tight vacuum oven: substantially as and for the purposes herein set forth.
2d. In the process of bread making where raising powders yeast or other artificial
means to produce lightness have been employed the reinforcement of such artificial
agents by steam of low tension produced from the water employed to mix the dough,
substantially as and for the purposes herein set forth.
3d. In the process of bread-making the employment of the steam of the water of
the dough as a leavening or raising force substantially as and for the purposes herein
set forth.
4th. In the process of Bread-making an air-tight vacuum oven substantially as and
for the purposes herein set forth..

page_text: his Specification was, upon the 10th day of September 1890, Amended under
Sections 18 to 21 of the Patents, Designs, and Trade Marks Act, 1883, on the
application of Thaddeus Hyatt (assignee).
in ovens thereгог.
To all whom it may conceru: Be it known that I THOMAS RICKETT of Southampton,
Hants, Mechanical Engineer have made CERTAIN NEW AND USEFUL IMPROVEMENTS IN
THE PROCESS OF BREAD RAISING AND BAKING AND IN OVENS THEREFOR and I 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 :-
Baking as commonly performed is conducted in ovens made and managed with
reference only to heat and with no necessity for being air-tight.
My improved process of baking requires in the oven an establishment of the
Under these conditions the water contained in the dough is not converted into steam at
a less temperature than 212° F. and if this temperature be reached the steam generated
can do nothing toward making the material "light "and "short" because dough when
heated beyond about 140° F. becomes incapable of forming the air-cells upon which the
lightness depends. According to this invention the raising or leavening quality and
power of steam at low tension is obtained owing to the water in the dough being converted
into vapour when the dough is-heated to about 110° F., this end being accomplished by
the use of a vacuum oren all as hereinafter more fully set forth, it being well known that
if air pressure be removed water will be converted into steam at a comparatively low
temperature.
To put the invention into practical use it is proposed to establish the following
conditions to wit: 1st that the Oven shall be air-tight, 2d that the air-tight oven
shall have its atmosphere reduced to a pressure less than that of the external air.
Bd that the air-tight vacuum oven shall be connected with a condenser to draw away
its steam and 4th these conditions require to be all in combination with the proper
mechanical arrangements necessary for producing and maintaining in the oven the
necessary degree of heat required for baking.
:
The object of my invention is These conditions being attained it is possible by this
invention to produce good bread (and under the term bread I include cake pastry &c.)
without that strict attention to previous raising of the dough required by the ordinary
oven and without the same necessity for materials such as lard butter &c. to produce
shortness that is required by the ordinary oven.
Under the oven conditions 1 have enumerated dough made of simple flour and
water only or seasoned with the ordinary substances made use of for such purposes,
as salt, sugar, soda &c. will without the addition of raising powders yeast, or any
artificial means for raising, become baked into good wholesome and light bread
superior to most, and equal to the best of ordinary fermented breads: while doughs
made with raising materials of any kind may be made with vastly a much less
and with equal effect quantity of such materials when baked in an oven provided with
the conditions I have herein set forth a peculiar shortness without shortening being
produced in the bread when baked by my new process.

page_text: I will first describe the means I employ to obtain the conditions needed in order to
earry out my new Process baking.
To distinguish my improved oven from the ordinary one, I call it the vacuum oven :
which oven I will now proceed to describe.
On the sheet of drawings hereto annexed and making part of this specification,
To clearly explain how the invention may be carried out reference is made to the
accompanying drawings in which Figure 1 is a side section shewing an oven of rec-
tangular shape.
Figure 2 is a cross section, Figure 3 represents the door of the oven, Figure 4,
represents the condensing apparatus.
The oven is made of either cast or plate iron, when of cast it is made of one piece
with an open end for the door. A indicates the oven, D the apparatus for exhausting
the air, C the steam condenser, D the oven door, E the firebox, F Steam Jet, G steam
boiler.
a is an air-pipe connection between the steam jet F, and the air tight chest b, which
air connection continues through the coiled pipe e in the steam condenser C, to the
bent short air pipe d, which terminates in the top of the oven A.
The door D is shewn in position on Fig. 1, and closed, the letter e indicating the
vulcanized india rubber cushion which makes the joint air-tight.
This metal oven is set in brickwork indicated by the letters f, E indicates the
fire-box under the oven the grate-bars: indicate the hot air flues that carry the
heat around the ovon: .. is a bed of firebrick under the oven bottom to protect it
against the sudden excess of heat: j. j. are screw-nuts on the door for tightening
where the door is shut against the rubber cushion, the steam boiler G, is set in brick-
work indicated by k, k.
0 is
Figure 5 is an enlarged view of the steam vacuum jet F to more clearly illustrate
its operation. m is an internal pipe through which steam from the boiler G, passes or
rushes when the exhaust is to be produced, is a sleeve or shroud that encases m,
the funnel shaped end of the sleeve or shroud n it is made separately and screwed on
as indicated, this funnel is made of copper or thin metal and thickened at r, r, by an
addition in which to make the screw: a counter screw thread is made in the sleeve n,
at this point and the funnel thus connected with it.
The steam pipe m from the point indicated by a- to its termination in the funnel o,
is tapered down to a knife edge, causing a gradual enlargement of the surrounding
air-space until the point . . is reached.
The branch pipe p, opens into the sleeve at or near the point where the steam
pipe m begins to taper, and connects the inside air of the oven with the air space in
the sleeve around the steam pipe m. The proportions and connection between the
steam pipe m and sleove, are so shaped and arranged as to prevent all tendency of the
steam from entering the air space of the sleeve in its rush from the boiler into
the funnel and thence into the open air, as a consequence of this the air of the oven
must be sucked or drawn out in proportion to the vacuum produced in the funnel and
shroud by the tenuity and force of the rushing steam.
EXPLANATION OF THE MECHANICAL ACTION OF THE OVEN AT WORK.
:
The dough to be baked having been placed in the oven and the door closed, the screw
nuts are turned until the door is pressed against the india rubber seat. The oxhaust
apparatus is now set to work until a vacuum of from ten to twelve pounds per square
inch is produced when the dough which in part has obtained a temperature of about
110 degrees will begin to rise and so continue until it has attained a temperature of
about 140 at which point or near it, it loses elasticity becomes short plastic and putty
like, and incapable of further expansion, as the process of baking goes on steam rises,
and so long as the exhaust is kept up, passes out through the air-pipe from the top

page_text: the air-tight chest 6 under the condenser.
I prefer to continue the veenum only until the bread is set: or for about half to
two thirds of the time required in the oven. When the action of the exhaust
apparatus is stopped the steam which rises from the bread will gradually reduce the
vacuum to zero, as this steam is not wanted in the oven a valve is provided for its
escape, the external pressure of the atmosphere becoming now balanced by that
within the oven the door may be freely opened at any time for examination of
the bread.
PHILOSOPHY OF THE VACUUM OVEN.
By the ordinary bread making processes the water of the dough is not converted
into steam-at-n less temperature than 212 degrees such steam cannot therefore do
anything towards making the dough light and short because dough at about 140 and
beyond becomes incapable of forming the air-cells on which lightness depends.
In my new process of bread making because of the lessened atmospheric pressure
within the vacuum even I am able to obtain the raising or leavening quality and
power of steam at low tension, the water in the dough beginning to be converted into
vapeur on the temperature of the dough becoming about 110 degrees : -water
theoretically in a perfect vacuum boiling at 70 degrees.
It thus happens in my improved process that extraneous or artificial means for
raising the dough have less work to perform and may consequently be used in smaller
quantities than where the baking is done in the ordinary way this not only works
economy of materials but it also saves time and likewise introduces an element of
precision and certainty with method and order unknown to the common modes in use.
Leavened bread baked by my process is light without bitterness and short and
tender without shortening materials, while in breads made with raising powder so
small a quantity is needed in comparison with ordinary use as to become unobjection-
able on the score of health and taste.
1 do not broadly claim the raising of dough by causing carbonic acid or other
gas in it to expand by removing the atmospheric pressure from it as such process has
heretofore been proposed, nor do I broadly claim the use of vacuum ovens for baking
bread, but
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.
1st. In the process of bread making, the raising and baking of the dough in an
the air-tight vacuum oven: substantially as and for the purposes herein set forth.
24. In the process of bread making where raising powders yeast or other artificial
means to produce lightness have been employed the reinforcement of such artificial
agents by steam of low tension produced from the water-employed to mix the dough,
substantially as and for the purposes herein set forth.
2nd. The process of bread making which consists in raising and baking bread dough
in a vacuum oven wherein the dough is raised by low tension steam formed within its own
substance by the same heat that bakes it, substantially as set forth.
3d. In the process of bread making the employment of the steam of the water of
the dough as a leavening or raising force substantially as and for the purposes herein
set forth.
4th. 3rd. In the process of Bread-making an air-tight vacuum oven substantially
as and for the purposes herein set forth.