Improvements in and connected with the Fermentation and Manufacture of Malt-wines.
Year: 1898

page_text: Date of Application, 4th Aug., 1898-Accepted, 2nd June, 1899
COMPLETE SPECIFICATION.
Improvements in and connected with the Fermentation and
Manufacture of Malt-wines.
I, Dr. ALBERT MUNSCHE, Chemist, of 267, Allee, Altona, in the Empire of
Germany, 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:-
This invention relates to certain improvements in and connected with the
fermentation and manufacture of malt-wines.
With regard to the product of my process it may be mentioned that it
resembles the known sweet wines, Tokay wine, sherry, port wine, etc. according
to the nature of the barm employed, and it differs from the so-called malt wines,
first, in its slight percentage of dextrine, and secondly, in its greater percentage
of flavoring substances. A characteristic group of constituents of grape-wines are
the flavoring substances. According to the experiments of Muller, Thorgan and
Georges Jaquemin, the formation of these flavoring substances is not exclusively
dependent upon the wine barm of the fermented must, but a portion of these
substances is already contained in the vine and passes from it into the grapes, and
thus into the finished drink. These flavoring substances are ether like bodies,
which are termed "fruit ethers." Such substances do not exist in malt.
Now as
additions of fruit-ethers of any kind whatever are excluded in my process the
flavoring substances forming rather a part of the malt-wort I have tried the use
of barm-forming fruit-ether and have thus attained the desired end. These barms
possess the property of producing, instead of alcohol, great quantities of fruit-
ether in the malt-wort. (Betriebskontrolle in den Gahrungsgewerben, Berlin,
edition of Paul Parey. Page 216, etc.) The characteristic properties of the kind
of barm used for the production of the flavor give rise to the different aromas.
The percentage of flavoring substances produced naturally gives a distinct wine
aroma to my malt-wine, which is free from the taste of malt and renders it a
nerve strengthening drink, which, moreover, in consequence of its great pro-
portion of malt extracts, is a nourishing and strengthening agent for invalids and
persons in a convalescent state.
In order to carry out my process, the following operations are necessary: first,
the cultivation of barms: second, the preparation and inversion of the cane sugar
solution to be added to the malt-wort; third, the production and treatment of
the malt-wort; fourth, the flavoring of the malt-wort mixed with inverted sugar;
fifth, the fermentation of the malt-wort by means of cultivated wine-barms and
dextrine barms added at intervals; sixth, the storage of the new wine.
In the production of a malt-wort for the cultivation of the barms I mix one
hundred and fifty kilogramms of ground kiln-dried malt in a copper or wooden
vat of about 600 litres capacity with four hundred and fifty litres of water at a
temperature of 30° centigrade, an agitator working therein at the same time.
After two hours the mixture is brought to a temperature of 60° centigrade, at which
temperature the mash should be left for two hours for the saccharifying process. After

page_text: this the mixture is raised to the boiling point, and the mash in a saccharified
condition is pressed out by means of a press similar to that used in the manu-
facture of fruit or currant wines. This expressed malt-wort is transferred to a
suitable vessel, where it is maintained in a sterilized condition.
Now for the cultivation of barms a kind of grape is chosen according as the
character of Tokay, Hungarian wine, sherry, or port wine is desired and is crushed
and the expressed must is allowed to ferment (in a small sterilized glass vessel
closed with cotton wool in connection with a thermostat) at 30° centigrade. A
small quantity of the fermenting must is then taken and a culture of the barm-
cells is carried on according to one of the known methods for example: (Hansens
method of cultivation with a solid nourishing medium). This culture is trans-
ferred into sterilized tubes. When a sufficient quantity of the barm has formed
upon the gelatine, a small portion of this barm is transferred by means of a
platinum wire into a Pasteur flask of one litre capacity about three quarters full
of the sweet malt-wort obtained as above described. After two days a sufficient
quantity of barm forms in the Pasteur flask, and this is further cultivated in a
copper flask containing from six to eight litres of the above mentioned wort.
this wort, when in complete fermentation, fifty litres of fresh wort are added, and
with these the so-called " sour barm-wort" the production of which is described
below. In order to increase the growth of the barm, it is advisable to periodically
expose the worts to sterilized air. The temperature of fermentation is about
50° centigrade.
To
The barms used for manufacture of the malt wines are: I. Suitable selected
pure culture wine barms and II. Dextrine fermenting barms. The reason for the
use of the latter named barm may be found in the following. It is well known
that the dextrines, which during the sugar generation process, produce isomaltose
as well as maltose, are not directly fermentable but require an initial inversion by
the after effect of the diastase during fermentation. It is quite certain that by
the use of a higher temperature which has to be employed for perfect sugar pro-
duction, and for destroying bacteria, the diastase is prevented from passing through
the mashing and sterilisation processes without being weakened, and the conse-
quence of this is a weak reaction of the diastase which will cease as soon as a
certain quantity or percentage of alcohol has been produced. If the dextrine
which has escaped the after effect is to be utilised in the production of alcohol
dextrine fermentation barms are used of which two are at present known. The
raising or culture of these two groups of barms takes place in lactic acid malt wort to
which there has been added, more preferably and advantageously before acidula-
tion a certain proportion of sugar.
In carrying out my fermentation process with wine barms the preparation of
malt wine barm in lactic acidulated malt-wort is necessary for the production of
a strongly developed sour-wine barm. This end is obtained by the process
of acidifying with lactic acid the "barm-wort" which may be so called as dis-
tinguished from the great or "principal” wort. The preparation of this barm-wort
is effected in the following manner: One hundred and fifty kilogramms of ground
malt are mixed in the same vat which was used for the production of the sweet
malt-wort with the same quantity of water, four hundred and fifty litres, and then
raised to a temperature of 70° centigrade by means of steam with agitation for
about four hours. The mash is maintained at this temperature until completely
saccharified and is then pressed out. The wort so obtained is transferred to a
second vat of the same size and brought to a specific gravity of 26° to 30° Ball. 5
by adding a solution of the finest quality of cane-sugar and is left to itself at a
temperature of about 55° centigrade.
mences accompanied with the formation of lactic acid, whereby products of lactic
At this temperature a fermentation com-
fermentation, develop.
The object of rendering the barm-wort sour is threefold-first, because the lactic 5
acid has a peptonizing effect upon the albuminous bodies of the malt, and thus
encourages the nourishment of the barm; second, because the lactic acid hinders

page_text: the appearance of nitro-organisms of a harmful nature; third, because the barn
thrives better in a sour medium than in a neutral.
When the desired degree of sourness of the barm-wort has been obtained, which is
usually the case after about eighteen to twenty-four hours, the barm-wort now
in a sour state is cooled to about 15° to 180 centigrade by means of a cooling-coil
placed therein and is mixed with the wine-barm in fifty litres of sterilized malt-
wort. This I call " sour wine barm." At the expiration of a fermentation of
twelve to fourteen hours the barm is ripe, i.e. the increase in the bulk of the
barm has attained its limit. During the fermentation a considerable increase of
temperature has taken place. It should be maintained at a temperature not
exceeding 32° by means of a cooler. A part of the " mature barm," as the sour
fermented barm-wort is called, about forty or fifty litres, is put aside to serve as
seed for the next preparation of barm. The remaining four hundred litres of
mature sour fermented barm-wort is used for fermenting the sweet principal wort
produced in the meantime.
The cultivation of fruit barm is similar to that described above for the sour
barm-wort. For the purpose of obtaining fruit-ether barm a glass bottle loosely
closed is filled with green malt or with very moist dried malt and stored in a
warm place. After a few days an intense smell of fruit-ether can be discerned.
A small quantity of this malt is put into sterilized wort and is cultivated in the
same manner as above described with reference to the wine-barms and the product
is what I call "fruit-ether barm."
In the preparation and inversion of the cane-sugar solution to be added to the
malt-wort I mix about six hundred kilogramms of white cane-sugar with forty
litres of water in a vat of about fifteen hundred litres capacity, the temperature
is raised by means of direct steam to 50° to 60° centigrade during agitation. This
sugar solution is mixed with fifty litres of sour malt-wort, and the liquid is
maintained at a temperature of 50° to 60° centigrade for about fifteen to sixteen
hours. For effecting complete inversion the liquid is afterwards raised to the
boiling point. When malt extract instead of sugar or a mixture of malt extract
and sugar is used the same method is adopted.
For the production and treatment of the principal malt-wort I mix one thousand
kilogramms of ground kiln-dried malt in a mash tub or vat with three times as
much water, and the mixture is gradually raised to a temperature of about 70°
centigrade by means of steam. This operation occupies from eight to ten hours
and after this the separation of the wort is effected by straining and pressure.
The liquids drawn off from the straining vat are united with the expressed liquids
and the inverted sour sugar before mentioned is added. The mixture obtained in
this manner is kept at a temperature of from 70° to 75° centigrade for about one
to two hours. It is then quickly cooled, preferably by means of a water spraying
cooler, to from 30° to 340 centigrade and is led by means of copper tubes to the
fermenting-vat.
The fermenting vat or tub is cylindrical and has a capacity of from seven thou-
sand to eight thousand litres. There is a cooling coil in this vat, by the agency of
which the temperature of the wort is regulated during the fermentation. Further,
there is an airfeeding tube in the fermenting vat, by which sterilized air can be
injected during the fermentation, according to requirements. The flow of wort
into the fermenting vat is so regulated that the entire quantity will be in the vat
within four or five hours. When the vat contains about five hundred litres of
wort, the preparation of fruit-ether barm before described is introduced into the
vat for the purpose of flavoring the malt-wort. At the commencement pure
sterilized air is injected, by which means the fruit-ether barm is caused to produce
a stronger flavor. As soon as the aroma formed by the fruit-ether barm is notice-
able the entrance of sterilized air is diminished and ripe sour wine barm is added
(four hundred litres) earlier or later, according to the degree of flavor desired.
In the fermentation of the principal wort the temperature should be maintained

page_text: at about 28° degrees centigrade, because as soon as the barm begins to increase in
bulk it will tend to rise in temperature.
After obtaining a certain percentage of alcohol the barm is exhausted, the
cells shrink together, and the fermentation would cease if new fresh strongly
fermenting barm were not added in the form of sour wine barm. For this purpose
new sour wine barm matter is cultivated in the manner already described. During
the process of fermentation I make. repeated additions of fresh barm to the
fermenting wort, so that as soon as certain percentage of sugar has been fermented
the fermentation is kept going by the addition of mature barm.
The entire duration of the fermentation is from four to six weeks, according to
the percentage of alcohol to be obtained. At the expiration of this time, or, in-
deed, before the expiration additions of fruit-ether barm are made, according to
requirements and according as a more or less strong flavour is desired, as in the
cultivation of the barm-forming fruit-ethers above described. When the principal
fermentation is finished, the new wine is separated from the remaining barm and
may be further fermented by the addition of dextrine barm if desired. The new
wine should be put into warm storage at a temperature at about 50° centigrade
After being stored for one month the albuminous bodies separated by the warmth
are removed by filtration and the clear wine is stored cold, almost as low as zero:
In this state a further separation takes place, which can be accelerated and com-
pleted by adding suitable quantities of tannin. The wine can be again filtered
and stored in barrels in a cellar in the usual manner to ripen.
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. A process of manufacture of malt wine consisting in the addition of a lactic
solution of sugar or of a lactic acid malt extract, subjecting the mixture to a
temperature within 63 and 75 deg. C. with the object of producing an aroma and
higher alcoholic contents and at the same time sterilizing the wort without
materially interfering with the diastase, substantially as set forth.
2. A process of manufacture of malt wine which consists in the addition to
malt wort which has not undergone lactic acid fermentation of a lactic acid
solution of sugar or of lactic acid malt extract, subjecting the mixture to a tem-
perature within the limits preferably of 70 to 75 deg. C. or a little lower, pre-
paring the stock with mature sour wine barm and adding similar barm thereto
from time to time during fermentation for the purpose of obtaining a higher
percentage of alcohol, substantially as set forth.
3. A process of manufacture of malt wine which consists in the addition of
malt wort which has not undergone lactic acid fermentation of a lactic acid
solution of sugar or of lactic acid malt extract, subjecting the mixture to a
temperature preferably within the limits of 70 to 75 deg. C. or a little lower,
treating the product with mature sour wine barm, adding similar barm thereto
during fermentation, adding fruit-ether barm during fermentation, and adding
dextrine barm finally after removal of the contained barm, substantially as set
forth.
4. A process of manufacture of malt wine which consists in the addition to
malt wort which has not undergone lactic acid fermentation, of a lactic acid
solution of sugar or of lactic acid malt extract, subjecting the mixture to a tem-
perature within the limits of 70 to 75 deg. C. or a little lower, treating the product
with mature sour wine barm, ádding similar barm thereto from time to time
during fermentation, adding fruit-ether, after removal of the contained wine
barm adding barm produced from dextrine thereto, and finally storing the product
at a high temperature but not exceeding 50 deg. C. substantially as set forth.
5. In the process of manufacture of malt wine fermenting a partially fermented
and sterilized wort by successive additions of mature sour wine barm and fruit-
either barm substantially as set forth.

page_text: 6. In the process of manufacture of malt wine, effecting the fermentation by
successive additions of mature sour wine barm, and thereafter completing the
fermentation by means of barm produced from dextrine after having removed
the wine barm.
7. In the process of manufacture of malt wine, effecting fermentation by successive
additions of mature sour wine barm, removing the barm residue, further ferment-
ing with barm produced from dextrine, and finally storing the product at a high
temperature not exceeding 50 deg. C. substantially as set forth.
Dated this 4th day of August 1898.
WHEATLEY & MACKENZIE,
40. Chancery Lane, London, W.C. Agents.