An Improved Process for the Fermentation of Worts which have been Rendered Antiseptic.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
An Improved Process for the Fermentation of Worts which have
been Rendered Antiseptic.
A communication by JEAN EFFRONT, of 72 Rue du Marais, Brussels, in the
Kingdom of Belgium, Doctor.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool and 6 Bank Street,
Manchester, both in the County of Lancaster, 118 New Street, Birmingham in
the County of Warwick and 31 High Holborn in the County of Middlesex,
Civil Engineer, do hereby declare the nature of this invention to be as
follows:-
The improved process for the fermentation of worts which have been rendered
antiseptic, which forms the object of this invention, is characterized by the setting
to work in such worts, more particularly in worts for distillery purposes, of yeast
which is capable of resisting the action of the antiseptic, and of thus preserving
intact its fermenting power.
Hitherto efforts have always been made to overcome the great obstacle to a
superior yield of alcohol, namely the existence of ferments of disease in the worts,
by eliminating them therefrom, or at least by paralysing them by the aid of certain
additions of antiseptics added to the worts in proportions calculated to be more
or less favourable to the desired object.
If it be true that this process of rendering the worts antiseptic has the effect of
rendering them unchangeable, it is certain on the other hand that the increased
yield in alcohol is not very considerable, and that these manifestations so little in
accord have given rise to the most erroneous hypotheses, even to that of admitting
that another cause than that of the ferments might be the cause of the inferiority
in the yield of alcohol.
But it is not so, and it is indeed the disease ferments which alone obstract the
work and diminish the return, and if worts which have been rendered antiseptic do.
not give the expected superior yield in alcohol, probably by reason of the paralysing
of the ferments, it is because it depends on a cause of a very different kind which
has hitherto escaped observations made, and which merely consists in the peculiarity
that the additions of antiseptics employed for the purpose of paralysing the
disease ferments, paralyse at the same time the yeast or fermenting power, which
they weaken, thus prejudicing the final yield, and this inconvenience is particularly
felt in the case of worts for distillery purposes fermenting relatively at very high
temperatures, and consequently the yield of alcohol is not appreciably greater
and may even be inferior to that which is obtained if the process be carried out
without the use of antiseptics. Even under the most favourable conditions all the
benefit which is expected from the use of antiseptics is not obtained, that is to say
from the point of view of the yield in alcohol.
Under these conditions it is evident that the solution of the problem is
exclusively subordinate to a perfect working of the yeast employed in the worts
which have been rendered antiseptic, and that a superior yield of alcohol will be

page_text: invariably obtained when it is possible to employ for the fermentation a yeast
prepared in such a way that its vital force, or its power of fermentation is not
affected by wort rendered antiseptic to a given degree, a method of working
which constitutes the characteristic of this invention, the extent of which com-
prises therefore in principle the use of any yeast having a property of vigour or
energy.
As a mode of preparing the yeast with a view to carrying out this improved
process of fermentation, recourse is made to the repeated and numerous experi-
ments made by the inventor, relative to the methodical cultivation of yeast in
antiseptics, by which it is possible to cause the yeast to endure considerable
additions of antisepties without affecting its fermenting power, and which therefore
enables it to be brought to that state of superior vigour which is necessary for
resisting the worts which have been rendered antiseptic.
Attention is first directed to the necessity which exists in this method of working
of only setting the yeast to work on worts rendered antiseptic by the same anti-
septic as that which served for the methodic cultivation of the yeast, the harmful
action of the two different antiseptics in the wort explaining itself quite
naturally.
The methodic cultivation of the yeast is based on the acclimatization of the
yeast in worts in which the antiseptic additions are successively and progressively
reinforced, this method enabling the yeast to be brought to endure an amount of
antiseptics inuch superior to that which the disease ferments can resist.
The result is, that a yeast capable of resisting a wort rendered so highly
antiseptic, will not only resist a wort less antiseptic, but will exert thereon also its
fermenting power with all its energy, so that in this method of working, the
improved process of fermentation is characterized by the use of yeast cultivated in
worts.rendered antiseptic to a superior degree to that of the wort which is to be
fermented, the antiseptic degree of which may in consequence be reduced in
practice to the amount of antiseptic strictly necessary for paralysing the disease
ferments.
Starting from this principle it has been found that, in practice, the antiseptic
degree of the last named wort for the cultivation of the yeast, must be at least
double that of the wort which is to be fermented, in order to obtain a maximum
yield in alcohol. The principle in question and its application are better explained
by the following quantitative example:
Taking as an antiseptic hydrofluoric acid, salicylic acid, picric acid, formic
aldehyde, nitro-cresol or even any other suitable antiseptic, it is found that a
quantity of 10 to 20 grammes per litre of wort in fermentation will suffice to
prevent the development in such wort of disease ferments. In order to work this
wort under the rational conditions hereinbefore mentioned, a yeast must be
employed which has been cultivated in wort progressively reinforced with additions
of antiseptics reaching 2 (10 to 20) or 20 to 40 grammes per litre.
By then employing this cultivated yeast in the quantity of 20 to 40 grammes
in the fermentation of wort rendered antiseptic with 10 to 20 grammes of the
corresponding antiseptic, the result of the action will correspond to that which
would be obtained in working by means of a good yeast a wort which has not
been rendered antiseptic, but is free from all disease ferments; in other terms a
maximum yield of alcohol will be obtained.
Dated this 23rd day of April 1895.

page_text: been Rendered Antiseptic.
A communication by JEAN EFFRONT, of 72, Rue du Marais, Brussels, in the
Kingdom of Belgium, Doctor.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street,
Manchester, both in the County of Lancaster, 118 New Street, Birmingham, in the
County of Warwick, and 31, High Holborn, in the County of Middlesex, Civil
Engineer, 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 :-
The improved process for the fermentation of worts which have been rendered
antiseptic, which forms the object of this invention, is characterised by the setting
to work in such worts (more particularly in worts for distillery purposes) of yeast
which is capable of resisting the action of the antiseptic, and of thus preserving
intact its fermenting power.
Hitherto efforts have always been made to overcome the great obstacle to a
superior yield of alcohol, namely the existence of ferments of disease in the worts,
by eliminating them therefrom, or at least by paralysing them by the aid of certain
additions of antiseptics added to the worts in proportions calculated to be more or
less favourable to the desired object.
If it be true that this process of rendering the worts antiseptic has the effect of
rendering them unchangeable, it is certain on the other hand that the increased
yield in alcohol is not very considerable, and that these manifestations so little in
accord have given rise to the most erroneous hypotheses, even to that of admitting
that another cause than that of the ferments might be the cause of the inferiority
in the yield of alcohol.
But it is not so, and it is indeed the disease ferments which alone obstruct the
work and diminish the return, and if worts which have been rendered antiseptic do.
not give the expected superior yield in alcohol, probably by reason of the paralysing
of the ferments, it is because it depends on a cause of a very different kind which
has hitherto escaped observations made, and which merely consists in the peculiarity
that the additions of antiseptics employed for the purpose of paralysing the
disease ferments, paralyse at the same time the yeast or fermenting power, which
they weaken, thus prejudicing the final yield, and this inconvenience is particularly
felt in the case of worts for distillery purposes fermenting relatively at very high
temperatures, and consequently the yield of alcohol is not appreciably greater and
may even be inferior to that which is obtained if the process be carried out
without the use of antiseptics. Eveu under the most favourable conditions all the
benefit which is expected from the use of antiseptics is not obtained, that is to say
from the point of view of the yield in alcohol.
'
Under these conditions it is evident that the solution of the problem is exclusively
subordinate to a perfect working of the yeast employed in the worts which have
been rendered antiseptic, and that a superior yield of alcohol will be invariably
obtained when it is possible to employ for the fermentation a yeast prepared in
such a way that its vital force, or its power of fermentation is not affected by
wort rendered antiseptic to a given degree, a method of working which constitutes
the characteristic of this invention, the extent of which comprises therefore in
principle the use of any yeast having a property of vigour or energy.
But in order that the yeast may exercise its vigorous properties, it must be able
to necessarily endure an amount of an antiseptic much greater than that of the

page_text: wort which it is intended to ferment, and from this point of view the quantities or
proportions of any antiseptics employed in the wort in practice may therefore be
reduced to a dose of antiseptics strictly necessary for paralysing the ferments of
disease, whereas the yeasts have been accustomed to support quantities much
greater by cultivation.
The cultivation of the yeast may be effected by means of any suitable anti-
_septics, such, for instance, as hydrofluoric acid, formic aldehyde, salicylic acid,
picric acid, or the like. In order to obtain a sufficiently high antiseptic degree for
the yeast, nine phases of cultivation are necessary under the following conditions.
The process will now be described as an example in the treatment of a litre of
wort.
:-
The process is as follows when hydro-fluoric acid is employed:
To one litre of wort of malt or maize there is mixed 10 grammes of beer
yeast, and to this mixture 02 grammes of hydrofluoric acid is added and the whole
is then left to ferment until the wort which previously weighed 18° Balling bas
descended to 9 Balling. The yeast is then collected on a filter and it is then
introduced afresh into a fresh lot of wort containing 03 grammes of hydrofluoric
acid. If after the fresh fermentation this wort has descended from 18° to
9° Balling, a fresh part of the wort containing 04 of hydrofluoric acid is fermented;
until it shall also have reached 9° Balling, and this process is continued, increasing
at each phase of the ultimate cultivation the proportion of antiseptic by 01 grammes,
until the litre of wort in question contains one gramme of hydrofluoric acid.
In order to obtain the same effect with the acid of formic aldehyde, instead
of '02 grammes in the first stage, there is employed 04 grammes and this succes-
sively until the last stage there are two grammes per litre of formic aldehyde
instead of one gramme.
In accordance with the above, if other antiseptics be employed, this treatment is
varied conformably with the efficacy of the antiseptic employed whilst the stages
in themselves always remain the same.
By this progressive augmentation of the antiseptic, more particularly by
commencing with a very small dose, no great delay results in the fermentation, and
the passage from one stage or dose to another necessitates from one to eight days.
After the last stage is accomplished, that is to say, with a dose of one gramme
of hydrofluoric acid per litre, it is well to renew the wort with the same dose for
several weeks.
If then in this operation 3 days are necessary for descending from 18° to
9° Balling the fermentation of the half of the sugar will be effected after some
renewals of the wort in 6 to 8 hours. Immediately this effect is obtained, the
yeast must be considered as being sufficiently acclimatised to the antiseptic and the
process with this object is terminated.
The Feast acclimatised in the manner herein before described has special
peculiarities. It hardly increases in a wort rendered antiseptic with the maximum
dose of antiseptic to which the yeast has been acclimatised. After the fermentation
an increase of 5 to 10 cells per 100 cells set in action is found at most. In addition
these yeasts are excessively sensitive to any change of medium and of temperature.
They will only work, for instance, at a temperature of 30° to 32° C., whilst at 25°
fermentation totally ceases.
When conveyed into a malt wort they do not work, and in a maize wort they
work very slowly, and in addition they do not keep. By reason of these properties
it is not industrially applicable because it is not transportable and so cannot be
handled otherwise, and for this reason must be subjected to a special treatment for
obviating these drawbacks.
This treatment must therefore be considered as being the second stage in the
manufacture of the acclimatised yeast which has been already herein before
partially described in a previous Patent, No. 4598, of 1895 and which is
characterised by the following process of treatment of the acclimatised yeast
according to the process described in the first period.

page_text: This process is based on the circumstance that it has been found that even after
desiccation of the yeast hereinbefore described, the latter preserves its fermenting
power, and that in this condition not only is it transportable, but also that it may
be preserved as desired:
In order to obtain yeast in this form, special precautions must be employed and
special measures taken. The yeast acclimatised in a grain wort containing the
maximum of antiseptic in which it can still work is filtered through a paper filter
r a filter press. The dregs containing yeast are pressed and mouldel into cakes.
These cakes are then placed in a stove in which vacuum is produced and in which
a temperature of about 35° C. is maintained. After the cakes of yeast have been
exposed for 5 or 6 days to this treatment it is ascertained that the yeast has again
formed spores. At this moment the temperature of the stove is increased and
brought to 45° C., always maintaining the vacuum in the stove. After staying
there 5 or 6 days in this atmosphere, the cakes of dregs are almost entirely dried,
and tliese dregs then furnish the very stable active yeast preserving the great.
fermenting power of the acclimatised yeast, and it is this yeast which is afterwards
employed for industrial fermentation. This is done in the following manner:-
A 100 grammes of these dried dregs are diluted in 10 litres of malt and maize
wort, the antiseptic in which the yeast has been acclimatised is added but in a .
lightly smaller dose than that with which the operation was previously performed.
For instance if the yeast has been acclimatised in one gramme per litre of hydro-
fluoric acid 08 of hydrofluoric acid will be taken for the wort. The wort with the
dregs is treated at the temperature of 30° C. and the moment of fermentation is.
awaited. This lasts generally from 2 to 3 days. As soon as the fermentation has
commenced, to the 10 litres of wort in fermentation there are added 40 litres of
the same but fresh wort containing the same quantity of antiseptic, then after
each period of 24 hours there is added to the wort four times its volume. Thus,
for instance, if we have 50 litres of yeasted malt such as has been hereinbefore.
obtained, there is added at the end of 24 hours 4 x 50 200 of fresh wort having
08 grammes per litre of hydrofluoric acid. The wort is then left from 5 to 6 days
to work, the yeast is completely ready, and the wort of 18° Balling descends in
24 hours to zero and even below.
=
There is thus obtained an industrial yeast for distilleries; and it is sufficient for
fermentation in the vats to take two hectolitres of these worts in order to ferment,
1.00 hectolitres.
It is therefore evident that by means of this system it is in no way necessary (as
it has been in the past) to introduce into distilleries enormous quantities of yeast.
in order to do the necessary work and that on the contrary any desired quantity:
may be produced or at least enormous quantities of yeast by introducing at the
commencement an insignificant quantity of some 100 grammes. The yeast thus
produced by acclimatisation in antiseptics is also much less exacting from the point.
of view of nutrition than ordinary yeasts, so that it may be applied very advan-
tageously also to the fermentation of molasses. It is well known in fact that in
order to ferment molasses with ordinary yeast it has been necessary hitherto to:
make yeast containing a very large proportion of grain in order to nourish the
yeast, that is to say, that you must have a yeast containing a minimum of
5 per cent. of grain, whilst by employing this acclimatised yeast it is hardly
necessary to introduce more than a half or a quarter per cent., and, in certain
cases, the acclimatised yeast.even allows of the grain being totally dispensed with.
It is exactly owing to this use of a large quantity of grain in the fermentation
of molasses that hitherto the fermentation has not been as favourable as it ought
to be.
Now with the acclimatised yeast, the question changes entirely, that is to say, if
it be desired to ferment fresh molasses it is sufficient in order to commence the
fermentation, to add yeast in very small quantities; but once the fermentation is
at work (that is to say, when, the molasses antisepticised to the desired degree have
been started in fermentation, by a small quantity of yeast, with which is mixed the

page_text: acclimatised yeast, and when the whole mass of molasses has started fermenting)
it is sufficient in order to ferment a second vat to take for instance half, or at least
a considerable part of a vat in fermentation and to mix it with the part of another
vat which is not in fermentation, and to act the same with the latter when the
fermentation has reached a maximum degree of fermentation, and so on successively
which is called "cutting off" (coupage) by vat.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be perforined, as communicated
to me by my foreign correspondent, I declare that what I claim is :-
1. A process for the fermentation of worts which have been rendered antiseptic,
characterised by the fermentation of such worts by the action of yeast which has
been acclimatised so as to be capable of enduring at least double the amount of
antiseptic inserted in the wort, such antiseptic being the same as that employed for
acclimatising the yeast, substantially as described.
2. In a process such as described, the preparation of yeast acclimatised to anti-
septics, characterised by the treatment of worts at 30° Centigrade minimum, with a
maximum proportion of 0.2 grammes of antiseptic (HFI) per litre in the first
stage of cultivation, increasing it by 01 at each stage of the subsequent cultivation
up to 1 gramme per litre, renewing the wort for each successive stage after it has
fallen in the next stage from 18° to 9° Balling and finally by the compression and
desiccation under vacuum of the dregs in two operations or stages one at 30° Centi-
grade, and the second at 45° Centigrade, with the object of imparting to the
acclimatised yeast the property of keeping or being preserved substantially as
described.
3. In a process such as described, the use instead of HFI of antiseptics having
analogous properties, and, conformably to the nature of the latter, the variation of
the antiseptic degree of the wort in proportion to the efficacy of the antiseptic, for
instance in the case of formic aldehyde from 02 to 04 in the first stage, and
increasing by 02 in each successive stage up to 2 grammes per litre substantially
as described.
4. The utilisation in distilleries of the herein described dregs yeast by diluting it
in the proportion of 100 grammes in 10 litres of wort rendered antiseptic to the
extent of 08, and after fermentation in four times this quantity of a similar wort,
(40 litres) and after fermentation by again four times this latter quantity (say
200 litres), then fermenting the whole and afterwards utilising the yeast wort in
the vats in the proportion of 2 to 100 hectolitres of wort rendered antiseptic to
about half the degree to which the yeast is rendered antiseptic substantially as
described.
5. The utilisation of yeast acclimatised according to the process hereinbefore
described in a barm containing at most at or a per cent. of grain, for the fermen-
tation of molasses-worts and eventually the total suppression of grain, and in the
latter case the fermentation of the molasses-worts by blending or mixing two vats,
substantially as described.
Dated this 23rd day of January 1806