IMPROVEMENTS IN THE PRESER- VATION OF MILK
Year: 1881

page_text: LETTERS PATENT to Edward Griffith Brewer, of 33, Chancery Lane, in the
"
County of Middlesex, for an Invention of IMPROVEMENTS IN THE PRESER-
VATION OF MILK." A communication from abroad by Ludwig Scherff, of
Berlin, in the German Empire.
PROVISIONAL SPECIFICATION left by the said Edward Griffith Brewer at
the Office of the Commissioners of Patents on the 29th October 1881.
"
EDWARD GRIFFITH BREWER, of 33, Chancery Lane, in the County of Middlesex.
'IMPROVEMENTS IN THE PRESERVATION OF MILK." (A communication from
abroad by Ludwig Scherff, of Berlin, in the German Empire.)
The object of this Invention is to preserve milk in its natural state without any
addition thereto whatever. This Invention consists in heating the milk in closed
vessels, such as glass bottles or tin boxes, to beyond the boiling point so as drive
out all the air, and next to prevent the entry of air containing gerr into the
vacuous space created by cooling down of the milk, the said gerins being the cause
of the spoiling of the milk.
The bottles, tins, or other vessels are filled with milk almost up to the beginning
of the neck, leaving a little space below the cork or other stopper. The cork is
driven down so far below the top of the neck as to leave a small space, say, for
instance, about a quarter of an inch between the top of the cork and the top of the
neck. A layer of paraffine wax, say, about a full eighth of an inch is then run in
on the top of the cork and thereon is placed a cork disc, which by means of a
staple closure or other means is kept from rising by reason of any internal pressure
in the bottle.
A number of bottles so filled and prepared are placed in a chamber or vessel
that can be hermetically closed and able to withstand an inner pressure of four to
five atmospheres. This chamber may be of any suitable form and be provided with
divisions or shelves for placing several rows of bottles one over the other. Into
this chamber steam of about two and a half to three atmospheres pressure is
introduced, the chamber being provided with a pressure gauge so as to regulate
Buice C71

page_text: the pressure. The steam having a temperature of about 230° F., in a short time
heats the milk in the bottles to the same temperature, whereby the milk expands
and the air contained between the milk and the cork will escape through the pores
of the cork and through the parathne rendered liquid. When the pressure in the
chamber has risen to two and a half to three atmospheres, the steam inlet may be
closed. The chamber is now left to cool down (which may also be accelerated by
artificial cooling), and the bottles are then removed and the staple closures taken
off. If it should appear desirable the corks may now be driven in further and the
space left above it in the bottle neck filled quite with paraffine wax.
The steam, instead of being led into the chamber, may be evolved therein, the
bottom being covered with a layer of water, which is heated by a steam coil or by
direct heat from a fire place.
Before the steam was let into the chamber it contained atmospheric air. The
steam however destroys all the germs in it. The milk expands by the heat right
up to the cork, and the air contained therein is mostly driven out thereby. In
cooling the milk contracts again, and air, which has been heated to 230° F., hence
containing no living germs, enters from the chamber into the bottles through the
corks. This air remains in between the milk and the cork, but it cannot do any
harm now as it is free from any living or life propagating substances. The same
holds good as to any air that may have remained in the bottle and not have been
driven out. Atmospheric air cannot afterwards enter the bottle because there is
now equilibrium between the air in the bottle and the outer atmosphere. The
meanwhile cooled layer of paraffine protects the cork itself from taking up germs
from the outer air and ensures the keeping of the milk. The last addition to the
thickness of the paraffine layer forms a further security.
The milk preserved as above will keep fresh for years, and has exactly the saine
taste as new milk.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Griffith Brewer in the Great Seal Patent Office on the
29th April 1882.
EDWARD GRIFFITI BREWER, of 33, Chancery Lane, in the County of Middlesex.
"IMPROVEMENTS IN THE PRESERVATION OF MILK." A communication from
abroad by Ludwig Scherff, of Berlin, in the German Empire.
The object of this Invention is to preserve milk in its natural state without
any addition thereto whatever. It is well known that fermentation producing
organisms are killed when exposed to a certain degree of heat. Boiled milk which
after cooling down is kept from the entry of air which contains such organisms or
germs will consequently be preserved from fermentation.
These fucts are according to this Invention made use of in the following manner,
and I will now describe it with reference to the accompanying Drawing, which
represents a vertical section through a bottle or vessel such as may be conveniently
used for the purpose of this Invention.
This Invention consists in heating the milk in closed vessels, such as glass bottles
or tin boxes, to beyond the boiling point so as to drive out all the air and next to
prevent the entry of air containing germs into the vacuous space created by
cooling down of the milk, the said germs being the cause of the spoiling of
the milk.
The bottles, tins, or other vessels, which may for instance be of the form shewn
on the Drawing, are filled with milk almost up to the beginning of the neck, say
to the line a, b, leaving a little space e below the cork or other stopper c. The
cork is drawn down so far below the top of the neck as to leave a small space d,
say, for instance, about a quarter of an inch or half an inch between the top of the
cork c and the top of the neck. A layer of paraffin wax, say about half the depth
of the space d, is then run in on the top of the cork and thereon is placed a cork
disc which by means of a staple closure or other means is kept from rising by
reason of any internal pressure in the bottle. On the Drawing is shewn the well
known "Fritzner wire staple closure with porcelain button f and india rubber
washer g; this latter is so elastic that air under pressure may find its way past it
from within but so that no air will enter the bottle from without, when in the
subsequent part of the process a partial vacuum is produced in the bottle and so
that it keeps the cork c from being forced out of the bottle neck during the
operation of heating the milk in the bottle.
"
A number of bottles so filled and prepared are placed in a chamber or vessel
with a cover or door that can be hermetically closed and able to withstand an
inner pressure of four to five atmospheres; it may suitably be made of iron or
copper. This chamber may be of any suitable form and be provided with divisions
or shelves for placing several rows of bottles one over the other. Into this
chamber steam of about two and a half atmospheres pressure is introduced, the
chamber being provided with a pressure gauge and a thermometer so as to be able
to regulate the pressure and observe temperature. The steam, having a tempe-
rature of about 230° F., in a short time heats the milk in the bottles to the same
temperature, whereby the milk expands so that the space e is reduced about half
and the air contained between the milk and the cork will escape through the pores
of the cork cand through the paraffin & rendered liquid and pass out by the india
rubber washer g. It is important that the volume of the space e be determined
before band by experiment so that the milk when heated by no chance can reach
up to the cork c. The expansion of the milk by heat reduces the space e as

page_text: already stated. When the pressure in the chamber has risen to about two and a
half atmospheres the steam inlet may be closed.
The chamber is now left to cool down (which may also be accelerated by
artificial cooling). The outer pressure on the bottle is hereby quickly reduced
while the heat stored up in the bottle produces steam from the milk, causing a
part of the steam and air mixture to be driven out through the cork and through
the liquid paraffin. When the bottle and its contents are quite cooled down a
partial vacuum is produced in the bottle, causing the liquid paraffin to enter the
upper part of the cork c under the pressure of the air which is enclosed between
the liquid paraffin and the closure fg. The bubble of compressed air above the
paraffin will thereby expand while the bubble of air and steain under the cork c
will contract and attenuate the air in the pores of the cork. After complete
cooling down the bottles are removed and the staple closures taken off.
It will be understood that the milk when quite cooled down has assumed its
original bulk, and the air space e has expanded again, while the paraffin in the
liquid state partly permeated the cork and partly remained above it, so that a
quite hermetically closure was effected. If it should appear desirable the corks
may however now be driven in further and the space left above it in the bottle
neck filled quite with paraffin wax.
The steam, instead of being led into the chamber, may be evolved therein, the
bottom being covered with a layer of water which is heated by a steam coil, or by
direct heat from a fire-place.
In cases where it is desirable for the sake of saving costs in transport-to-reduce
the bulk of milk it may be thickened-or condensed without any addition of any
-kind of material to any desired or required consistency in a vacuum and then put into
bottles, tin canisters, or similar vessels, provided with a neck of such a width that a
tea spoon may conveniently be inserted for removing portions of the contents.
These bottles containing such thickened or condensed milk are then treated
in exactly the same manner as hereinbefore described with regard to the un-
thickened milk except so far that in order to prevent a burning of the milk a
temperature of only about 212° to 230° F. is employed in the closed chamber
wherein the bottles are placed which correspond to the employment of steam of
about 1 to 2 atmospheres.
Before the steam was let into the chamber this latter contained atmospheric air.
The steam however destroys all the germs in the chamber.
The milk expands by the heat but not right up to the cork, and the air contained
therein is mostly driven out thereby. In cooling the milk contracts again and a
little air which has been heated to 2:30° F., hence containing no living gerins enters
from the chamber into the bottles through the corks. This air remains in between
the milk and the cork, but it cannot do any harm now as it is free from any living
or life propagating substances. The same holds good as to any air that may have
remained in the bottle and not have been driven out. Atmospheric air cannot
afterwards enter the bottle, because there is now established an equilibrium
between the air in the bottle and the outer atmosphere. The meanwhile cooled
layer of paraflin protects the cork itself from taking up germs from the outer air
and ensures the keeping of the milk.
paraflin layer forms a further security.
fresh for years.
The last addition to the thickness of the
The milk preserved as above will keep
And having thus described and ascertained the nature of this Invention and the
manner of carrying the same into effect, I declare that I do not broadly claim the
employment of paraffine wax as a means for stoppering in cases like those herein
contempated, because it has probably heretofore been proposed to be used for such
purpose, but I wish it to be distinctly understood that I believe it can only
effectually fulfil its purpose of forming an air-tight closure when used in connection
with the method or process herein before described, wherein it, by reason of the said
peculiar process, partly penetrates into the stopper and partly forms a cover on the

page_text: top of it; if the paraffin wax is poured in the open air in the ordinary manner it
does not prevent the subsequent entry of germs of organisms.
I claim as the Invention communicated to me,--
First. The preparation or preparatory mode of charging bottles or other vessels
with milk consisting in filling them only so far as to leave a considerable space
between the milk and the cork, which latter is then driven in so far as to leave a
recess or space between it and the top of the neck, which space is then partly filled
with paraffin wax poured in, the bottle being then provided with a provisional
closure which permits the driving out of the air from the bottle during a subsequent
heating process while it prevents the cork from being driven out of the neck, and
allows the formation of a bubble of compressed air between the paraffin and the
cork, substantially as and for the purpose set forth.
Second. The combined process consisting of the preparatory mode of charging
bottles or other vessels with milk claimed in the preceeding claim, and of the
subsequent heating of the bottles so charged by means of steam in a hermetically
closed chamber for the purpose of killing the ferment producing germs, and of the
subsequent cooling in the said chamber, and of the removal therefrom and the
taking off of the provisional closure, substantially as and for the purpose set forth.
Third. The condensing or thickening of milk in a vacuum without admixture of
preserving agents, and then treating it as firstly and secondly claimed.
In witness whereof, I, the said Edward Griffith Brewer, have hereunto set
my hand and seal, this Twenty seventh day of April, in the year of our
Lord One thousand eight hundred and eighty two.