Improvements in and relating to Preserving Beer.
Year: 1897

page_text: Improvements in and relating to Preserving Beer.
I, JOHANN FRANZ HUGO GRONWALD, of 32, Schönhauser Allee, Berlin, in the
Enipire of Germany, Chemist, do hereby declare the nature of this invention to
be as follows:-
This invention relates to a process for rendering beer capable of being kept
whilst at the same time avoiding undesirable alterations in the flavour, and is
based on the following observations and experiments.
If beer, more particularly fresh or not sufficiently purely fermented beer, or
under-fermented (fermented from below) or over-fermented" (fermented from the
surface) beer, be tested as regards taste and smell, it shows itself more or less impure
according to the kind of beer. The reason of this appearance is that peculiar
volatile bye-products formed during the fermentation are given off by the beer.
If such beer be warmed for the purpose, of pasteurizing or sterilizing it, these
fermentation products make their presence known by producing in any case
under the action of the air remaining in the beer such tastes and smells as
characterize beers pasteurized according to the methods hitherto employed.
The applicant has firmly established this by experiments, and has found that
this well known alteration of beer during or after pasteurization or sterilization
does not take place if, before the heating of the beer, these bye-products formed
during the fermentation together with the remaining air be removed from the
beer, and this is preferably done before the beer is pasteurized or sterilized by
purifying it by mechanical means either in vacuum by drawing off the volatile
constitutents and then scrubbing with an indifferent gas, preferably carbonic
acid, or by direct repeated scrubbing with the same preferably after a preliminary
warming of the beer. The beer thus treated showed, under these experiments,
according to the repetition of these operations, an almost completely pure taste
and smell and could be subjected to the pasteurizing without the undesired
alterations of taste and smell taking place.
On the basis of the experiments effected it is therefore according to the present
invention preferable to expose the beer which is to be pasteurized to the action
of a greater or lesser vacuum and to draw off the volatile constituents thereby
released preferably by means of a pump or by the assistance of an indifferent
gas (preferably carbonic acid) conveyed thereto, It is self-evidently immaterial
.

page_text: for the purpose of the invention in what manner the vacuum is produced, for
instance whether by means of an air pump or air condenser or the like. If
desirable the beer which has been exposed to the vacuum may then be subjected
to cold or be heated to about 20-30° C. under pressure and scrubbed with car-
bonic acid and then only may a heating and cooling in the presence of carbonic
acid take place.
If it be not desired to employ vacuum, the removal of the deleterious bye-pro-
ducts and remaining air may take place by repeated scrubbing with carbonic
acid under pressure, whilst a heating of the beer to about 20-30° C. may pre-
ferably take place.
In the use of vacuum a scrubbing with an indifferent gas or rather carbonic
acid after the vacuum treatment and before the pasteurization is not always
to be employed but only when it is certain that the treatment under vacuum
has been carried out until the volatile bye-products of the beer and any remain-
ing air still present therein have been actually completely removed.
As regards the treatment of the beer under vacuum, experiments have shown
that this treatment has not to take place at an increased temperature because
when the beef is warmed during the formation of a partial or entire vacuum
the aroma of the beer, more particularly of the hops and alcohol, is lost.
The mechanical removal of the volatile bye-products of the beer and of any
remaining air existing therein would therefore appear to be the more advan-
tageous, more particularly when working on a large scale in a separate vessel.
In this case it is possible to easily carry on the operation continuously; but
where it is a question of time and continuous working is not necessary, this
mechanical removal of the volatile bye-products both by means of vacuum and
also by repeated scrubbing with an indifferent gas (preferably carbonic acid)
may take place in the pasteurizing vessel itself.
The practical carrying out of the present invention will be now more parti-
cularly described.
In the use of a separate purifying vessel utilizing vacuum, the beer which
is to be treated is first conveyed by means of a pipe and rose into a suitable
vessel. This vessel which is in communication with a vacuum producing ap-
paratus such for instance as an air pump by means of a pipe and which is pro-
vided with an inlet pipe for an indifferent gas for instance carbonic acid, has
first a vacuum produced in it which is maintained as far as possible during the
operation. By this means the volatile ferment constituents which are deleterious
to taste and smell and any remaining air contained in the beer are removed
therefrom. As soon as the vessel has been sufficiently filled with such beer, the
said beer is forced over into the pasteurizing vessel connected with the purifying
vessel by means of a pipe which may be closed by means of a valve, the said
forcing over being produced either by means of carbonic acid which is conveyed
into the vessel through the inlet pipe or by means of a pump. The pasteurizing
vessel is of course first deprived of air and preferably filled with carbonic acid.
In order to assist the action of the vacuum, the purifying vessel may be pro-
vided with a suitable stirring apparatus or agitator. After this vacuum treat-
ment the beer may if desired be either first scrubbed with carbonic acid under
pressure in the vacuum or purifying vessel or only in the pasteurizing vessel.
The beer is then either directly after the vacuum treatment or after the subse-
quent scrubbing just mentioned has taken place, heated and cooled in the
pastuerizing vessel in the presence of and in contact with carbonic acid, as will
now be more particularly described and is then filled into the transport vessels
or barrels.
If it be desired to effect the mechanical removal of the volatile bye-products
or the remaining air from the beer without vacuum, gradually by means of a
suitable scrubbing of the beer with an indifferent gas (more particularly carbonic
acid), this may be effected in a separate vessel, the beer being then driven over
into the pasteurizing vessel as was the case with the vacuum vessel, or the beer

page_text: may be subjected to treatment in the pasteurizing vessel (heating vessel) itself.
The process may be more particularly described as regards the latter method
of working. The pasteurizing boiler or vessel is filled with beer up to about
four-fifths of its capacity. The mixture of air and carbonic acid contained above
the beer is compressed by means of carbonic acid conveyed therein, and then,
after the closing of the vessel, any carbonic acid existing in the same is forced
into the beer by means of a stirring apparatus. For this object the boiler is
provided with a discharge pipe capable of being closed and also with a carbonic
acid supply pipe capable of being closed. It is also provided with a shaft on
which the stirrers or arms are mounted. The carbonic acid forced into the beer
thus takes the place of the volatile bye-products contained in the beer (air,
other gases and volatile compounds) which accumulate in the upper part of the
vessel together with such parts of the carbonic acid as again escape from the
beer. For the purpose of more rapidly separating the bye-products the beer may
be heated to about 30° C. The bye-products accumulated in the upper part of
the boiler, in addition to the unabsorbed carbonic acid, may be removed by a
blow-off pipe by means of a fresh current of pure carbonic acid. By a frequent
repetition of this scrubbing and expelling and letting-off of the carbonic acid at
a suitable temperature of about 20-30° C., a thorough removal of the dele-
terious volatile bye-products and remaining air from the beer may be effected
so completely that the heating (pasteurizing) of the beer may then take place.
The following apparatus is suitable for this purpose. The heating boiler is
preferably provided with a shaft running right through and having stirrer arms
mounted thereon, by the action of which the heating of the beer is rendered even
whilst the carbonic acid admitted or introduced into the heating boiler by means
of a pipe may be thoroughly combined with the beer. The heating of the beer
preferably takes place by means of expanded steam which is conveyed to a heat-
ing casing or jacket through a pipe. In order to increase the heating surface,
tubes are provided in the interior of the boiler which communicate with the
heating casing or jacket. Cooling liquids may be admitted through a pipe on
the casing or jacket and steam may if desired be admitted to the boiler through
another pipe.
The beer is admitted into the heating boiler through a pipe cap-
able of being closed by means of a valve and after treatment may be withdrawn
through a valve and pipe. In order to control the temperature thermometers
are employed, and safety valves are fitted on the casing or jacket and on the
heating boiler itself. Inspection windows or peepholes are also provided to enable
the interior of the heating boiler to be inspected. On the under part of the.
heating casing a pipe fitted with a valve is provided for carrying off the water
of condensation and in the lower part of the heating boiler another pipe for
cleaning and discharging purposes is similarly arranged.
A discharge pipe is arranged for carrying off the air containing the carbonic
acid expelled from the beer, and a pipe for connecting, if desired, with a vacuum
apparatus in case it is preferred to support this repeated scrubbing by the use
of vacuum.
The subsidiary apparatus such as filters, collecting vats and the like which
communicate with the heating boiler by means of pipes capable of being shut
off need not further be described, but if desired they may like the heating boiler
be made to work with vacuum.
As already stated the removal of the undesirable volatile bye-products of the
beer and the remaining air may be effected by the combined use of vacuum and
scrubbing. This combined use may be carried out by the vacuum treatment
being effected in a separate vessel and the subsequent scrubbing either in the
same vessel or in the heating vessel. This combined use of vacuum and scrub-
bing may however take place in the heating vessel itself. In this case the heat-
ing (pasteurizing) of the beer is effected in an hermetically closed vessel and
under constant agitation of the beer with carbonic acid until the sterilization is
sufficient after which a rapid cooling is effected. All this takes place constantly

page_text: in a carbonic acid atmosphere and under pressure whereby any re-infection of
the beer is avoided and a re-saturation of the beer with carbonic acid is attained.
If it be desired to produce beer rich in carbonic acid this may be attained by
introducing an increased quantity of carbonic acid and by more strongly im-
pregnating the beer with it.
Natal thi 19th Joy of Novomhow 1807
Improvements in and relating to Preserving Deer.
I, JOHANN FRANZ HUGO GRONWALD, of 32, Schönhauser Allee, Berlin, in the Empire
of Germany, Chemist, do hereby declare the nature of this invention and in what
imanner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
This invention relates to a process for rendering beer capable of being kept whilst
at the same time avoiding undesirable alterations in the flavour, and is based on the
following observations and experiments.
If beer, more particularly fresh or not sufficiently purely fermented beer, or under-
fermented (fermented from below) or over-fermented (fermented from the surface)
beer be tested as regards taste and sinell, it shows itself more or less impure according
to the kind of beer. The reason of this appearance is that peculiar volatile bye-
products formed during the fermentation are given off by the beer. If such beer be
warined for the purpose of pasteurizing or sterilizing it, these fermentation products
Inake their presence known by producing in any case under the action of the air
remaining in the beer such tastes and smells as characterize beers pasteurized according
to the methods hitherto employed.
The applicant has firmly established this by experiments, and has found that this
well known alteration of beer during or after pasteurization or sterilization does not
take place if, before the heating of the beer, these bye-products formed during the
fermentation together with the remaining air be removed from the beer, and this is
preferably done before the beer is pasteurized or sterilized by purifying it by
mechanical means either in vacuum by drawing off the volatile constituents and then
scrubbing with an indifferent gas, preferably carbonic acid, or by direct repeated
scrubbing with the same preferably after a preliminary warming of the beer for the
said scrubbing. The beer thus treated showed, under these experiments, according
to the repetition of these operations, an almost completely pure taste and smell and
could be subjected to the pasteurizing without the undesired alterations of taste and
smell taking place.
On the basis of the experiments effected it is therefore according to the present
invention preferable to expose the beer which is to be pasteurized to the action of a
greater or less vacuum and to draw off the volatile constituents thereby released
preferably by means of a pump or by the assistance of an indifferent gas (preferably
carbonic acid) conveyed thereto. It is self-evidently immaterial for the purpose of
the invention in what manner the vacuum is produced, for instance whether by means
of an air pump or the condensation of steam or the like. If desirable the beer which
has been exposed to the vacuum may then be subjected to cold or be heated to about
20-30° C under pressure and scrubbed with carbonic acid and then only may a
Heating and cooling in the presence of carbonic acid take place.

page_text: If it be not desired to employ vacuum, the removal of the deleterious bye-products
and remaining air may take place by repeated scrubbing with carbonic acid under
pressure, whilst a heating of the beer to about 20-30° C may preferably take place.
In the use of vacuum a scrubbing with an indifferent gas or rather carbonic acid
after the vacuuin treatment and before the pasteurization is not always to be employed
but only when it is certain that the treatment under vacuum has been carried out
until the volatile bye-products of the beer and any remaining air still present therein
have been actually completely removed.
As regards the treatment of the beer under vacuum, experiments have shown that
this treatment has not to take place at an increased temperature because when the
beer is warmned during the formation of a partial or entire vacuum the aroma of the
beer, more particularly of the hops and alcohol, is lost.
The mechanical removal of the volatile bye-products of the beer and of any remaining
air existing therein would therefore appear to be the more advantageous, more
particularly when working on a large scale in a separate vessel. In this case it is
possible to easily carry on the operation continuously; but where it is a question of
time and continuous working is not necessary, this mechanical removal of the volatile
bye-products both by means of vacuum and also by repeated scrubbing with an
indifferent gas (preferably carbonic acid) may take place in the pasteurizing vessel
itself.
The practical carrying out of the present invention will be now more particularly
described reference being made to the accompanying drawings in which-
Figure 1 is a vertical section of a purifying vessel; Figure 2 is a horizontal section
of the pasteurizing vessel, and Figure 3 a cross section of same.
In the use of a separate purifying vessel utilizing vacuum, the beer which is to be
treated is first conveyed by means of a pipe vand rose into a suitable vessel V,
(Figure 1). This vessel which is in communication with a vacuum producing
apparatus such for instance as a pump by means of a pipe v and which is provided
with an inlet pipe for an indifferent gas for instance carbonic acid, has first a vacuum
produced in it which is maintained as far as possible during the operation. By this
means the volatile ferment constituents which are deleterious to taste and smell and
any remaining air contained in the beer are removed therefrom. As soon as the
vessel has been sufficiently filled with such beer, the said beer is forced over into the
pasteurizing vessel connected with the purifying vessel by means of a pipe D which
may be closed by means of a valve, the said forcing over being produced either by
means of carbonic acid which is conveyed into the vessel through the inlet pipe v² or
by means of a pump p. The pasteurizing vessel A is of course first deprived of air
and preferably filled with carbonic acid. In order to assist the action of the vacuum,
the purifying vessel V may be provided with a suitable stirring apparatus or
agitator R. After this vacuum treatment the beer may if desired be either first
scrubbed with carbonic acid under pressure in the vacuum or purifying vessel or only
in the pasteurizing vessel. The beer is then either directly after the vacuum treat-
ment or after the subsequent scrubbing just mentioned has taken place, heated and
cooled in the pasteurizing vessel in the presence of and in contact with carbonic acid.
as will now be more particularly described and is then filled into the transport
vessels or barrels.
If it be desired to effect the mechanical removal of the volatile bye-products or the
remaining air from the beer without vacuum, gradually by means of a suitable
scrubbing of the beer with an indifferent gas (more particularly carbonic acid), this
may be effected in a separate vessel, the beer being then driven over into the
pasteurizing vessel as was the case with the vacuum vessel, or the beer may be
subjected to treatment in the pasteurizing vessel (heating vessel) itself.
The process may be more particularly described as regards the latter method of
working. The pasteurizing boiler or vessel is filled with beer up to about four-fifths
of its capacity. The mixture of air and carbonic acid contained above the beer is
compressed by means of carbonic acid conveyed therein, and then, after the closing
of the vessel, any carbonic acid existing in the same is forced into the beer by means

page_text: of a stirring apparatus. For this object the boiler is provided with a discharge pipe
capable of being closed and also with a carbonic acid supply pipe capable of being
closed. It is also provided with a shaft on which the stirrers or arms are mounted.
The part of the carbonic acid forced into the beer thus takes the place of the volatile bye-
products contained in the beer (air, other gases and volatile compounds) which and driven
out by the said carbonic acid gas, which bye-products then accumulate in the upper
part of the vessel together with such parts of the carbonic acid as again escape from
the beer. For the purpose of more rapidly separating the bye-products the beer may
be heated to about 30° C. The bye-products accumulated in the upper part of the
boiler, in addition to the unabsorbed carbonic acid, may be removed by a blow-off
pipe by means of a fresh current of pure carbonic acid. By a frequent repetition of
this scrubbing and the forcing-in and letting-off of the carbonic acid at a suitable
temperature of about 20-30° C., a thorough removal of the deleterious volatile bye-
products and remaining air from the beer may be effected so completely that the
heating (pasteurizing) of the beer inay then take place.
The following apparatus (shown in Figures 2 and 3) is suitable for this purpose.
The heating boiler A is preferably provided with a shaft B running right through and
having stirrer arms b mounted thereon, by the action of which the heating of the
beer is rendered even whilst the carbonic acid admitted or introduced into the heating
boiler by means of a pipe K may be thoroughly combined with the beer. The
heating of the beer preferably takes place by incans of expanded steam which is
conveyed to a heating casing or jacket A¹ through a pipe C. In order to increase the
heating surface, tubes A2 are provided in the interior of the boiler which communicate
with the heating casing or jacket. Cooling liquids may be admitted through a pipe F
to the casing or jacket A¹ and steam may if desired be admitted to the boiler A
through another pipe C. The beer is admitted into the heating boiler through a
pipe capable of being closed by means of a valve D and after treatinent may be with-
drawn through a valve D¹ and pipe. In order to ascertain the temperature
thermometers c are employed, and safety valves d are fitted on the casing or jacket
and on the heating boiler itself. Inspection windows or peepholes f are also provided
to enable the interior of the heating boiler to be inspected. On the under part of the
heating casing a pipe y fitted with a valve is provided for carrying off the water of
condensation and in the lower part of the heating boiler A another pipe 1 for cleaning
and discharging purposes is similarly arranged.
A discharge pipe r is arranged for carrying off the air expelled from the beer and
containing carbonic acid and a pipe for connecting if desired with a vacuum
apparatus in case it is preferred to support this repeated scrubbing by the use of
vacuum.
The subsidiary apparatus such as filters, collecting vats and the like (not shown in
the drawings) which communicate with the heating boiler by means of pipes capable
of being shut off need not further be described, but if desired they may like the
heating boiler be made to work with vacuum.
As already stated the removal of the undesirable volatile bye-products of the beer
and of the remaining air may be effected by the combined use of vacuum and
scrubbing. This combined use may be carried out by the vacuum treatment being
effected in a separate vessel and the subsequent scrubbing either in the same vessel
or in the heating vessel. This combined use of vacuum and scrubbing may however
take place in the heating vessel itself. In this case the heating (pasteurizing) of the
beer is effected in an hermetically closed vessel and under constant agitation of the
beer with carbonic acid until the sterilization is sufficient after which a rapid cooling
is effected. All this takes place constantly in a carbonic acid atinosphere and under
pressure whereby any re-infection of the beer is avoided and a re-saturation of the
beer with carbonic acid is attained.
If it be desired to produce beer rich in carbonic acid this may be attained by
introducing an increased quantity of carbonic acid and by more strongly impreg-
nating the beer with it.

page_text: 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 :--
A process for preserving beer, which consists in removing before sterilising by
heating the volatile or gaseous constituents contained in said beer by mechanical
means and the use of a vacuum without increasing the temperature which con-
stituents deleteriously affect the taste and smell, said operation being assisted in its
action by scrubbing the beer with an indifferent gas, such as carbonic acid under
pressure, and if desired slightly warming it for this scrubbing action, whilst instead
of a vacuum a repeated scrubbing with carbonic acid may also take place, the beer
thus treated being afterwards heated and cooled in contact with carbonic acid, sub-
stantially as hereinbefore described and with the object set forth.
2. An apparatus for preserving-beer-in-the-manner-hereinbefore-described, con-
sisting of vessel (A) provided with stirrers and-a-casing (A1) capable of being
filled-with-a-heating-or-cooling-mixture-and-connected by-means-of-suitable pipes
with-an-air-pump-or-other-means-of-producing vacuum;-and-with-a-carbonie-neid-
gas-supply, substantially as-hereinbefore-set-forth-and-shown in the accompanying-
drawings.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.