The Production Of Vinegar From Honey
Vinegar, or dilute acetic acid, is
produced by a process of fermentation
from certain vegetable substances.
After alcoholic fermentation has taken
place there follows, under suitable
conditions, a further decomposition, by means
of which the alcohol is converted into a more
highly oxidized body, acetic acid, with water as
a by-product.
These condi
ions require that the liquid
shall contain alcohol, nitrogenous matter, and
alkaline salts in certain proportions, and that it
shall be in contact with the air, at a suitable
temperature, for a sufficient length of time.
The researches of Pasteur showed the
process of oxidation to be due to a microscopical
fungus (mycoderma aceti), possessing the power
of condensing oxygen and conveying it to
the fermentable substance. This organism,
which is a true bacterium, as the fermentation
proceeds, forms a leathery membrane (slightly
differing according to the substance fermenting)
on the surface of the liquor, which constitutes
the so-called mother of vinegar, or vinegar
plant.
The oxidation of alcohol into acetic acid can
also be performed independently of the organic
agent. Finely divided platinum, for instance,
is capable of effecting disintegration of the
alcohol, and of placing it in immediate contact
with the oxygen of the atmosphere, thus
accomplishing the acetification.
Vinegar, on the continent, is prepared from
weak or sour wine, hence its name (~vin aigre.~)
In this country it is, to a large extent, produced
from an infusion of malt, but considerable
quantities of inferior quality are made from sour
beer, etc.
The vinegars thus produced, if properly
purified, and providing no injurious adulterants
are resorted to, are, for many purposes, almost
all that can be desired; but for table use, for
sauces and salads, where delicacy of flavour
is appreciated, and for medicinal purposes
where pureness and wholesomeness are essential,
I venture to say that no vinegar can be compared
with that produced from +Honey+.
~In the first place it possesses a delicious
flavour and aroma, altogether lacking in the
ordinary vinegar.~
Agreeableness of taste and smell are to
a large extent dependent upon the substance
from which the vinegar is manufactured, and it
is impossible to supply these artificially.
That the malt vinegar manufactured in
this country is conspicuously wanting in these
qualities must be a matter of general experience.
Moreover, owing to its great cheapness,
acetic acid distilled from wood (besides being
employed for pickling and other purposes, for
which it is well adapted), diluted and treated
with volatile oils, is every year superseding to a
larger extent the vinegars in general use. That
this bears no comparison as regards the agreeable
qualities, even with the ordinary vinegars,
need scarcely be pointed out.
On the other hand, +Honey+, of all saccharine
substances, containing as it does all the essentials
for harmonious bouquet and flavour, is the one
~par excellence~, from which we might expect to
produce an ideal vinegar. The result is found
amply to justify the anticipation, and that its
superiority in this respect will be duly appreciated
by the connoisseur in salads and condiments goes
without saying; but, indeed, so marked is this
distinction that I venture to think it would be
readily admitted by all who gave it a trial.
~On the ground of wholesomeness honey
vinegar is to be preferred.~
It has been clearly ascertained that large
quantities of vinegar sold in this country contain
injurious adulterants and impurities. Many
samples, upon analysis, have been found to
include a considerable percentage of sulphuric
acid, or nitric acid, added either as a preservative
or to increase the acidity. Others have contained,
as the results of carelessness in manufacture,
such poisonous ingredients as copper, arsenic,
and lead. Little wonder that disagreeable
consequences so often follow the taking of
vinegar, even in small quantities!
Immunity from these impurities and
adulterants, producing as they so frequently
do injurious effects, especially in the case of
invalids, is surely greatly to be desired, and
every possible improvement, either in respect
of the material employed or in the process of
manufacture of so important an article of consumption,
surely deserves to receive the most
careful attention.
MODE OF PRODUCTION.
If honey and water in proper proportions
be exposed to the atmosphere, at a suitable
temperature, for a sufficient length of time,
acetic fermentation will in due course ensue.
At the same time, to obtain the best results,
careful attention must be given to certain
details, and various precautions taken. The
alcoholic ferment must be carried on under
suitable conditions, in order that it may be
complete. The temperature must be neither
too high, nor too low. Suitable and sufficient
nutrient material also for the ferment germ must
be present; that is a proper proportion of nitrogenous
matter, together with certain inorganic
salts, which may be added in the form of a little
ammonium phosphate and potassium tartrate.
The acetic fermentation which follows must
also be regulated with due care, and not allowed
to continue longer than necessary, or deterioration
of the liquor will take place with a gradual
loss of acidity.
The fining also of the liquor must be carefully
attended to, in order to render it perfectly
clear and bright.
And finally, it is only when the alcoholic
and acetic fermentations have been effected, in a
completely satisfactory manner, and the vinegar
stored for a sufficiently long period under the
most suitable conditions, that the ripening
process is effected, without which it will be
found lacking in that agreeable flavour and
aroma which are its special characteristics.
[Sidenote: Proportion
of Honey
to Water.]
In the first place, we have to
determine the proper proportion of
honey to water.
Commercial Vinegar is required by law to
contain a minimum of 3 per cent. acetic acid.[2]
Proof Vinegar contains 5.4 per cent., with
a specific gravity of 1.006 to 1.019. For all
ordinary purposes this is a convenient strength
and first-class vinegars contain about this percentage.
Of course, the percentage of acetic acid is
dependent on a satisfactory alcoholic fermentation
and suitable conditions for the development
of the acetic germ; but, supposing the conditions
favourable, it is possible to obtain from an
aqueous solution of 1 part honey to 8 of water,
about 5 per cent. acetic acid. A suitable
proportion will thus be 1 part honey to from
7 to 8 parts of water by weight.
[Sidenote: Suitable
Receptacles.]
When made in small quantities
almost any open vessel will serve as
a receptacle for the liquor, always excepting
glazed or metal ones, in which vinegar must
never be allowed to stand. Owing to the
solvent effects of the acid, the liquor is, in these
cases, liable to be injuriously contaminated.
The vessel used should be covered with
muslin or cream cloth, to protect from insects,
etc.
A small cask is also a convenient receptacle,
but this should not be filled more than three
parts full and the bung hole must be left open,
protected with gauze or other coarse material.[3]
[Sidenote: Starting
the Fermentation.]
In due course, if left alone, alcoholic
fermentation, by a natural process,
will be set up; but I am inclined to think, from
my own experience, that it is best to add, in the
first instance, a small quantity of yeast. If, as
sometimes happens, the fermentative action be
too slow, putrefaction of a portion is liable to
take place, and the vinegar is spoilt.
The acetic fermentation is accelerated by
the addition of vinegar plant, and also by the
presence from the commencement of a small
quantity of vinegar.
[Sidenote: Temperature.]
A suitable temperature is 70 deg. Fah.,
or from that to 80 deg. Summer is
therefore by far the best time for vinegar
making, as this temperature is then easily
obtainable, especially if the vessel be exposed
to the heat of the sun.
At a little over 100 deg. Fah. the development
of the acetic germ ceases, while below
68 deg. it is gradually arrested.
[Sidenote: Duration
of
Process.]
The length of time before the completion
of the process varies according to
circumstances. While usually, under completely
favourable conditions, in from six to eight
weeks sufficient acetification has taken place,
not unfrequently a longer period is required.
[Sidenote: Racking
and
Clearing.]
When the proper degree of acetification
is reached, the liquor should be strained,
or, if in a cask, be racked into a fresh one,
without tilting. Then fined with isinglass,
or allowed to settle for a week or two, when it
may be drawn off clear and bottled. It may
subsequently require decanting and re-bottling.
The membrane or plant is useful for restarting
the action, but it must not be allowed to
remain for any length of time out of the liquor,
or be exposed to a low temperature, or it will be
injured.
[Sidenote: Colour.]
The colour will at first be found to be
quite light, but in course of time it will assume
an amber shade and gradually darken with age.
That this colouration may proceed as rapidly as
possible, the vinegar should be bottled in light
glass bottles, and exposed to the light.
* * * * *
Dilute acetic acid has been in general use
from remote times.
The ancient Hebrews used it, as we know
from the several allusions to it in the Old
Testament. It is mentioned also in the New
Testament. The Greeks and Romans, too,
made use of it. It is frequently spoken of by
classical writers, as Pliny, Livy, and others.
In our own times it is almost universally
employed for culinary and preservative purposes,
besides being largely used medicinally.
Vinegar is anti-scorbutic and anti-bilious.
Largely diluted it forms a very refreshing
beverage. It has been in past ages and in
modern times so used by soldiers on long
marches, and by others employed on hard and
exhausting labour, with beneficial results.
The vapour of vinegar inhaled greatly
relieves hoarseness, and, diluted as a gargle, is
useful in throat complaints.
Honey and honey vinegar in equal quantities,
and taken a teaspoonful at a time, is an
excellent remedy for sore throat and cough.
Mixed with water it is cooling and
invigorating for sponging the body.
Taken in moderation, owing to its effect
upon fatty and other substances, vinegar is an
~aid to digestion~. Pure vinegar is usually only
unwholesome if taken in large quantities.
~Raspberry Vinegar.~--Pour 1 pint of honey
vinegar on a quart of bruised raspberries.
Let it stand in a closed vessel for three
days, and stir occasionally. Strain through
flannel without squeezing, and to 1 pint of
liquor put 1-1/4 lb. of honey. Boil for ten
minutes, skim, and bottle when cold.
* * * * *
One great advantage in using honey vinegar
is that, being quite free from sulphuric or nitric
acid, it does not stain silver or table linen.
* * * * *
C_2H_6O + O_2 = H_2O + C_2H_4O_2
Alcohol + Oxygen = Water + Acetic Acid.
The proportions of the chemical constituents of Acetic Acid are as
follows:--Carbon 46.83, Oxygen 46.82, Hydrogen 6.35.