Heat of boiling Water may at once be lessened to any assigned Degree of
Warmth, by a proper Addition of cold Water; due Regard being had to the
Season of the Year, and the Temperature of the Air. This Improvement,
with that mentioned above, of reducing the two Operations of Brewing
and Fermentation to one, will be attended with considerable Advantage.
With regard to the proper Quantity of Water, it must be observed, that
if too little be used, a viscid clammy Mixture will be produced,
little disposed to ferment, nor capable of extracting all the soluble
Parts of the Malt. On the other hand, too much Water renders the
Tincture thin and aqueous, and by that means increases the Trouble and
Expence in all Parts of the Operation. A due Medium, therefore, should
be chosen; and Experience has shewn, that a Wash about the Goodness
of that designed by the _London_ Brewers for Ten Shilling Beer, will
best answer the Distiller’s Purpose. When a proper Quantity of Water
is mixed with the Malt, the whole Mass must be well agitated, that
all the soluble Parts of the Malt may often come in contact with the
aqueous Fluid, which being well saturated after standing a proper time,
must be drawn off, fresh Water poured on, and the Agitations repeated,
till at last the whole Virtue, or saccharine Sweetness of the Malt is
extracted, and only a fixed husky Matter remains, incapable of being
dissolved by either hot or cold Water.
The third requisite Particular is, that some certain Additions be
used, or Alterations made according to the Season of the Year, or the
Intention of the Operator. The Season of the Year is very necessary to
be considered. In the Summer, the Water applied to the Malt must be
colder than in the Winter; and in hot sultry Weather, the Tincture
must be suddenly cooled, otherwise it will turn eager; and, in order to
check the too great Tendency it has to Fermentation, when the Air is
hot, it will be necessary to add a proper Quantity of unmalted Meal,
which being much less disposed to Fermentation than Malt, will greatly
moderate its Impetuosity, and render the Operation suitable to the
Production of Spirits, which, by a too violent Fermentation, would, in
a great Measure, be dissipated and lost.
CHAP. II.
_Of Fermentation._
The tincture, or, as the Distillers call it, the Wash, being prepared,
as in the foregoing Chapter, it is next to be fermented; for, without
this Operation, no vinous Spirit can be produced.
By Fermentation is meant that intestine Motion performed by the
instrumental Efficacy of Water, whereby the Salt, Oil and Earth of a
fermentable Subject, are separated, attenuated, transposed, and again
collected, and recomposed in a particular Manner.
The Doctrine of Fermentation, is of the greatest Use, and should be
well understood by every Distiller, as it is the very Basis of the
Art; and, perhaps, if more attended to, a much purer Spirit, as well
as a greater Quantity of it, might be procured from the same Materials
than at present. We shall therefore lay down a concise Theory of
Fermentation, before we proceed to deliver the Practice.
Every fermentable Subject is composed of Salt, Oil, and a subtile
Earth; but these Particles are so small, that, when asunder, they are
imperceptable to the Senses; and, therefore, when mixed with an aqueous
Fluid, they leave it transparent; neither have fermentable Bodies any
Taste, except that of Sweetness.
These Particles are each composed of Salt, Oil and Earth, intimately
mixed in an actual Cohesion, Connexion, and Union; and, therefore, when
any one of those Principles too much abounds in any Subject, so that an
intimate Union is prevented, the whole Efficacy of the Fermentation is
either stopped or impaired, or at least limited to one certain Species.
This equal Connexion of Salt, Oil and Earth into a single compound
Particle, forms a Corpuscle soluble in Water; or, to speak more
philosophically, this compound Corpuscle is, by means of its saline
Particles, connected with the aqueous Corpuscles, and moved up and down
with them. But where these Corpuscles are not thus connected with the
Water, a Number of them join together, and form either a gross, or a
loose, chaffy, and spungy Matter.
When these compound Particles are diluted with a small Quantity of an
aqueous Fluid, they feel slippery, clammy, and unctuous to the Touch,
and affect the Taste with a kind of ropy Sweetness. And when a proper
Quantity of the Fluid is added, a Commotion is presently excited, and
afterwards a subtile Separation.
This Commotion and Separation first begins in the whole Substance; for
before the Addition of Water, the Subject may remain in dry, solid, and
large Pieces, as in Malt, Sugar, _&c._ which being reduced to Powder,
each Grain thereof is an Aggregate of many smaller compound Corpuscles;
these being put into Water, dissolve, and separately float therein,
till at length, they become so small as to be invisible, and only
thicken the Consistence of the Liquor.
These Corpuscles being thus separated from one another, there next
ensues a Separation of their component Particles; that is, the Salt,
the Oil, and the Earth, are divided by the Interposition of the aqueous
Particles.
The first Commotion is no more than a bare Solution; for the saline
Particles being easily dissolvable in Water, they are immediately laid
hold of by the aqueous Particles, and carried about with them. But the
succeeding Separation, or fermentative Motion, is a very different
thing; for by this the saline Particles are divided from those of Oil
and Earth, partly by the Impulse of the others in their Motion, and
partly by the Force of the aqueous Particles, which are now continually
meeting and dashing against them.
This Motion is performed by the Water, as a Fluid, or Aggregate of an
infinite Number of Particles, in actual and perpetual Motion; their
Smallness being proportionable to that of the fermenting Corpuscles,
and their Motion, or constant Susceptibility of Motion, by Warmth, and
the Motion of the Air, disposing them to move other subtile moveable
Corpuscles also. The certain Agreement of Figure, or Size between the
aqueous Particles, and those of the Salt in the fermentable Subject,
tends greatly to increase this Commotion; for, by this means, they are
readily and very closely connected together; and therefore move almost
like one and the same compound Corpuscle; whilst the Water is not at
all disposed to cohere immediately with either the Oil or Earth. And
thus an unequal Concussion is excited in the compound Corpuscles of the
fermentable Subject; which Concussion at length strikes out the saline
Particle, loosens the others, and finally produces a Separation of the
original Connexion of the Subject.
An aqueous Fluid, therefore, is the true, and indeed the only,
Instrument for procuring a fermentable Motion in these compound
Corpuscles of the Subject: For were an oily Fluid poured upon any
fermentable Subject, no vinous Fermentation would ensue; as the Oil
could neither give a sufficient Impulse on the compound Corpuscles,
which are grosser than its own constituent Particles, nor divide the
oily or saline Particles of the Subject from their Connexion with the
others, which detain, and, as it were, envelope, or defend them from
its Action.
The compound Corpuscles of the fermentable Subject being affected by
the perpetual Motion of the Particles of the aqueous Fluid, a proper
Degree of Motion is necessary, or that the Particles move with a
proper Degree of Velocity, which principally depends on external Heat.
A considerable Degree of Cold, indeed, will not absolutely prevent
Fermentation, though it will greatly retard it; and a boiling Heat
will prevent it still more. A tepid, or middle Degree of Heat between
Freezing or Boiling, is therefore the most proper for promoting and
quickening the Operation.
The Admission of Air, also, though not of absolute Necessity, yet
greatly promotes and quickens the Action, as being a capital Instrument
in putting in a proper Degree of Motion the oily Particles of the
Subject. But whilst the Air thus contributes to hasten the Effect, it
causes at the same time by its Activity some remarkable Alterations in
the oily Particles; for it not only moves, but absolutely dissolves
and displaces them from their original Connexions; and thus carries
them off with itself from the whole Mass. And, therefore, though the
Consideration of the Air does not so properly belong to Fermentation in
the general, yet it does in particular; as having an accidental Power
to alter every Species of this Operation: Consequently its Agency ought
to be well understood, either to procure Alterations at pleasure in the
fermenting Mass, or to prevent and correct impending Dangers.
The oily Particles thus separated and dissolved by the Air, are
also elastic, though they probably derive that Property from their
Intercourse with the Air itself, and their being rendered extremely
minute.
When, therefore, an aqueous Fluid is added to a fermentable Subject
exposed to a temperate Heat, a fermentative Struggle immediately
arises, the saline Part of the compound Particles being dissolved
by the continual intestine Motion of the Water, and carried up and
down with it in all Directions, amidst an infinite Number of other
Particles, as well fermentable, as aqueous ones; whence, by this
Collision and Attrition, the saline Particles are dissolved, and
separated from their Connexion with the oily and earthy. And as the
oily Particles are the most subtle and elastic, they would, by this
means, be thrown up to the Surface of the Liquor, and carried off by
the Air, were they not closely connected with the earthy ones, whose
Gravity prevents their Evaporation, and, by coming in contact with
others of the same kind, form Aggregations, and sink down, with the
oily Particles, to the Bottom. But before these can form a Bulk too
large to be supported by the Water, many of the oily Particles are,
by their frequent Collisions with the aqueous Fluid, separated from
the earthy ones; and, by Degrees, more strongly connected again with
the saline ones; whilst, on the other hand, the same saline Particles
imbibe some of the earthy ones, which being left single, upon their
Separation from the oily Particles, floated about separately in the
Fluid.
And hence proceed the several different Consequences of Fermentation;
_viz._ 1. From the Separation of the saline Particles of the
fermentable Subject proceeds the tart, saline, or acid Taste of the
Liquor; which is more sensible at first, before the Liquor is duly
composed and settled, or the due Arrangement and Connection of the
saline Particles with those of the oily and earthy Kinds, completed:
After which the Liquor proves milder, softer, or less pungent. 2. From
the oily Particles being set at liberty, proceeds the strong Smell
of the Liquor, and the Head or shining Skin upon the Surface. 3. The
earthy Particles collecting together in Clusters, cause the Fluid to
appear turbid, and afterwards a visible earthy, or clay-like Matter
to be precipitated: And some of the earthy Parts, in their Motion,
arriving at the Head, or oily Skin on the Surface, cause it to thicken;
and afterwards taking it down along with it, thus constitute the Lees
which abound in Oil. 4. From this new Struggle or Collision, which
is productive both of Solution, and a new Connection in the saline
and earthy Corpuscles, proceeds the Ebullition in Fermentation. And,
lastly, by the same repeated Coalition of the oily with the aqueous and
saline Particles, the inflammable Spirit is produced.
Having thus laid down a concise Theory of Fermentation, we shall now
proceed to the Practice.
The Wash being brought to a tepid, or lukewarm State in the Backs, a
proper Quantity of a good-conditioned Ferment is added; but if the
Ferment be solid, it should be previously broke into small Pieces, and
gently thinned either with the Hand, Whisp, _&c._ in a little of the
tepid Liquor. A complete and uniform Solution, however, should not be
attempted, because that would greatly weaken the Power of the Ferment,
or destroy its future Efficacy. The whole intended Quantity, therefore,
being thus loosely mixed with a moderate Parcel of the Liquor, and kept
in a tepid State, either by setting it near the Fire, or otherwise,
and free from the too rude Commerce of the external Air; more of the
insensibly warm Liquor ought to be added, at proper Intervals, till, at
length, the whole Quantity is properly set to working together. And,
thus, by dividing the Business into Parts, it may much more speedily
and effectually be performed, than by attempting it all at once.
The whole Quantity of Liquor being thus set to work, secured in a
proper Degree of Warmth, and defended from a too free Intercourse of
the external Air, Nature itself, as it were, finishes the Process, and
renders the Liquor fit for the Still.
By Ferments, we mean any Substance, which, being added to any rightly
disposed fermentable Liquor, will cause it to ferment much sooner and
faster than it would of itself; and, consequently, render the Operation
shorter; in contradiction to those abusively called so, which only
correct some Fault in the Liquor, or give it some Flavour. Hence we
see, that the principal Use of Ferments is to save Time, and make
Dispatch in Business; whilst they only occasionally, and, as it were,
by Accident, give a Flavour, and increase the Quantity of Spirit. And,
accordingly, any fermentable Liquor, may, without the Addition of any
Ferment, by a proper Management of Heat alone, be brought to ferment,
and even more perfectly, though much slower, than with their Assistance.
These Ferments are, in general, the Flowers and Fæces of all
fermentable Liquors, generated and thrown to the Surface, or deposited
at the Bottom, either during the Act of Fermentation, or after the
Operation is finished.
Two of these are procurable in large Quantities, and at a small
Expence; we mean, Beer-Yeast and Wine-Lees; a prudent and artificial
Management, or Use of which, might render the Business of Distillation
much more facile, certain and advantageous.
It has been esteemed very difficult, and a great Discouragement, in
the Business of Distillation, to procure a sufficient Stock of these
Materials, and preserve them at all times ready for use. The whole
Secret consists in dexterously freeing the Matter from its superfluous
Moisture; because in its fluid State, it is subject to a farther
Fermentation, which is productive of Corruption; in which State it
becomes intolerably fœtid and cadaverous.
The Method of exposing it to the Air till it has required a proper
Consistence, is subject to great Inconveniencies; and so peculiar and
careful a Management necessary, that it rarely succeeds.
The best Way, therefore, is to press it very slowly and gradually, in
a thick, close, and strong Canvas Bag, after the manner of Wine Lees,
by the Tail-press, till it becomes a kind of Cake; which, though soft,
will easily snap, or break dry and brittle between the Fingers. Being
reduced to that Consistence, and closely packed up in a tight Cask,
it will remain a long Time uncorrupted, preserve its Fragrancy, and
consequently, fit to be used for fermenting the finest Liquor.
The same Method is also practicable, and to the same Advantage, in the
Flowers or Yeast of Wine; which may be thus commodiously imported from
abroad: Or, if these cannot be procured, others of equal Efficacy may
be procured from fresh Wine Lees, by barely mixing and stirring them
into a proper warm Liquor; whence the lighter, or more volatile and
active Parts of the Lees, will be thrown to the Surface, and may easily
be taken off, and preserved, by the above-mentioned Method, in any
desired Quantity. And hence, by a very easy Process, an inexhaustible
Supply of the most useful Ferments may be readily and successively
procured, so as to prevent for the future all Occasion of Complaint for
want of them, in the Distiller’s Business.
Experience has demonstrated, that all Ferments abound much more in
essential Oil, than the Liquor which produced them; and consequently
they retain, in a very high Degree, the Smell and Flavour of the
Subject. It is therefore requisite, before the Ferment is applied, to
consider what Flavour is intended to be introduced, or what Species of
Ferment is most proper for the Liquor.
The Alteration thus caused by Ferments is so considerable, as to render
any neutral fermentable Liquor, of the same Flavour with that which
yielded the Ferment. This Observation is of much greater Moment than
will presently be conceived; for a new Scene is hereby opened, both in
the Business of Distillation, and others depending upon Fermentation.
It must, however, be observed, that its Benefit does not extend to
Malt, treated in the common Method; nor to any other Subject but
what affords a Spirit tolerably pure and tasteless: For, otherwise,
instead of producing a simple, pure, and uniform Flavour, it causes
a compound, mixed, and unnatural one. How far the fine Stiller may
profit by it, well deserves his Attention; and whether our native Cyder
Spirit, Crab Spirit, _&c._ which have very little Flavour of their own,
may not, by this Artifice, be brought nearly, if not intirely, into the
State of some foreign Brandies, so highly esteemed, is recommended to
Experience.
It is common with Distillers, in order to increase the Quantity of
Spirit, give it a particular Flavour, or improve its Vinosity, to add
several things to the Liquor, during the Time it is in a State of
Fermentation; and these Additions may properly be reduced to Salts,
Acids, Aromatics, and Oils.
All rich vegetable Juices, as Treacle, Honey, _&c._ which either want
a natural Acid, have been deprived of it, or contain it in too small
a Quantity, will be greatly improved by adding, at the Beginning of
the Operation, a small Quantity of the vegetable or fine mineral
Acids; as Oil of Sulphur, Glauber’s Spirit of Salt, Juice of Lemons,
or an aqueous Solution of Tartar. These Additions will either give, or
greatly improve the vinous Acidity of the Subject, but not increase the
Quantity of the Spirit, that Intention being performed by Aromatics
and Oils.
All pungent Aromatics have a surprising Quality of increasing the
Quantity of the Spirit, as well as in altering, or improving the
Flavour; but their Use requires that the Fermentation should be
performed in close Vessels. And if a large Quantity be intended to be
added, Care must be taken not to do it all at once, lest the Oiliness
of the Ingredients should check the Operation. But if the Flavour be
the principal Intention, they should not be added till the Operation
is nearly finished. After the same Manner a very considerable Quantity
of any essential vegetable Oil may be converted into a surprisingly
large Quantity of inflammable Spirit; but great Caution is here also
necessary not to drop it too fast, or add too large a Quantity at a
time, which would damp the Fermentation; it being the surest Method
of checking, or totally stopping this Operation, at any Point of Time
required. The best Method, therefore, of adding the Oil, so as to
avoid all Inconveniencies, is to rub the Oil in a Mortar with Sugar,
which the Chemists call making an _Olæosaccharum_, by which Means the
Tenacity of the Oil will be destroyed, and the whole readily mix with
the Liquor, and immediately ferment with it. The Distiller would do
well to consider these Observations attentively, as he may thence form
an advantageous Method of increasing the Quantity of Spirits, and at
the same Time greatly improve their Quality and Flavour.
But in order to put these Observations in practice, particular Regard
must be had to the containing Vessel in which the Fermentation is
performed, the Exclusion of the Air, and the Degree of the external
Heat or Cold.
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