The plain practical process of Malting pale Malt, according to the most approved English method.
Suppose you are about to malt spring or summer barley, and that your steep contains sixty bushels. The time generally allowed for this kind of grain to remain in steep is from forty to forty-eight hours, taking care to give two waters; the first water is to continue on the grain twenty-four hours, then run off, and fresh water put on. This precaution is essentially necessary, in order to make clean bright malt, and should never be omitted. It is further right, at each watering, to skim off the surface of the water the light grain, chaff, and seed weeds, that are found floating on it; all this kind of trash, when suffered to remain in the steep, is a real injury to the malt, and considerably depreciates its value when offered for sale, and not less so when brewed. The depth of water over the barley in the steep need not exceed two or three inches, but should not be less. When the barley has remained in steep the necessary time, the water is let off by a plug hole at the bottom of the steep, with a strainer on the inside of the hole; when the barley is thus sufficiently strained, it should be let down by a plug hole in the bottom of the steep into the couch frame on the lower floor, (or adjoining to it, which would be the better construction,) which is no more than a square or oblong inclosure of inch and a half boards ledged together, and about two feet deep, of sufficient capacity to hold the contents of the steep, and so placed, in upright grooves, as to ship and unship in this frame. The steeped barley is to remain for twenty-four hours in the frame, when it should be broke out, and carefully turned from the bottom to the top, nearly of the same thickness it was in the frame, not less than sixteen or eighteen inches, where it should be suffered to remain twenty-four hours longer, or until the germination begins to appear: but this will be always shorter or longer, according to the temperature of the season, and is generally ascertained by sinking your hand towards the middle of the heap, and bringing up a handful of the grain, which, if regularly germinated, will make its appearance in every grain of barley, by appearing white at one end; at this stage of the process, (supposing the temperature of your malt house sixty degrees,) the heap should be extended on the floor, to the thickness of eight inches; after which it should be turned three or four times a day, according to the season, and the progress of vegetation; gradually reducing the thickness of the couch to four or five inches; but it should be remarked, that as soon as the root begins to dry and wither, the watering pot is to be used; the judicious management of which is one of the most important parts of the process of malting, and should be paid particular attention to. One watering, well applied, will, in most cases, answer the purpose. Two thirds of the whole quantity of water should be given to the upper surface of the couch, then turn it, and give the remaining third of the water to the couch when turned. The whole quantity of water to be used for sixty bushels of American spring barley, may be averaged at fifty-four gallons; this quantity will, consequently, allow thirty-six gallons to be as evenly distributed over the surface of the couch for the first water, as possible; the remaining eighteen gallons to be put on in the same way: when the couch is turned after this last watering, the whole couch should be turned back again; thus, in every turning, the bottom and top should always exchange places. In this stage of the process, care should be taken to turn the couch frequently, to prevent the growth of the root, in order to give the greater facility to the growth of the blade, it being essentially requisite to keep that of the root stationary, to prevent a waste of strength in the grain. Three or four days after watering, is generally found a sufficient time for the blade to grow fully up to the end of the grain; farther than which it should not be suffered to proceed. The couch should be now checked in its growth, and thrown on the second or withering floor, where it should be laid thin, and frequently turned; this continued operation will bring it dry and sweet to the kiln, to which it may be committed without further delay. Although the common practice is to throw it up into what is commonly termed a sweet-heap, and so remain from twelve to twenty-four hours, or until you can hardly bear your hand in it; then, and not before, is it considered fit to go on the kiln. This is a practice that cannot be too much condemned, or too generally exploded, as producing the very worst consequences; a few of which I will mention. Green malt, thus treated, becomes in a manner decomposed; and beer brewed from such malt will never keep long, acquiring a disagreeable, nauseous flavour, rapidly tending to acidity, beside becoming unusually high coloured. Although the malt, before grinding, will have all the appearance of pale malt, this quality can be easily accounted for by the high heat the malt is suffered to acquire in the heap before putting it on the kiln. What I have here mentioned will, I trust, suffice to recommend a more judicious mode of practice. Forty-eight hours for malt to remain on the kiln is enough, as pale malt can be completely dried in that time, if frequently turned, and properly attended to. It is further worthy of remark, that barley malt should in no case exceed fifteen or sixteen days from the steep to the kiln, and is often more successfully effected in twelve or thirteen days. The common practice of maltsters is to allow twenty one days, which generally brings the green malt in a mouldy state to the kiln, to the great injury of flavour and preservation in beer brewed from such malts; whereas, the grain should be brought as sweet and dry as circumstances will allow of to this last and important operation of malting, every part of which requires minute and continued attention. When you suppose your malt sufficiently dry, make a round space in the centre of your kilncast by shovelling the malt to the extremities; after which, sweep this space, and shovel back again your malt from the walls and angles into it; make a round heap of the whole on the centre of your kiln, sweep your kiln all round the foot of your heap; so let it stand two hours, then throw it off; this last operation is performed to give every chance for equal drying. The practice of many maltsters is to take seventy two hours to dry their pale malt, keeping all the time a very slow and slack fire, this is another capital error, and should be corrected with the former ones. Various are the opinions entertained, as to the best mode of preserving malt after coming off the kiln: some are of opinion that the circumambient air should have a free access to it; this opinion, I admit, might have weight if such malt was to be immediately brewed; but where it is allowed to remain in heap for four or five months, and gradually become cool, the less air admitted to have access to it the better; this has been the practice and opinion of the most judicious maltsters I have been acquainted with, and, consequently, is what I would recommend, except in the case of immediate use, where exposure becomes necessary, particularly after grinding, as malt so treated will bear a higher liquor, and yield a more preserving extract.
Winter Barley.
To avoid useless and unnecessary repetitions, it is enough simply to state, that winter barley, being a weaker bodied grain than summer, requires less watering, consequently, a less time in steep, say 36 to 40 hours, and about 32 gallons of water to sixty bushels will be sufficient on the floor; the other treatment the same.
Oats the same,
with about 24 gallons of water on the floor, for sixty bushels, divided as directed in the case of summer and winter barley; the remaining part of the process the same.
Rye Malt.
Rye may be steeped 48 hours, with 48 gallons of water on the floor; the remainder of the process the same, quantity of grain sixty bushels.
Wheat.
The above time in steep, and same proportion of water on the floor, will answer to make wheat malt, suppose 60 bushels, varying somewhat according to season, the time of steeping, and bringing to the kiln; the remainder of the process the same.
Indian Corn Malt, a valuable auxiliary to Brewing materials.
This species of grain well managed, and made into malt, will be found alike useful to the brewer and distiller, but it is peculiarly adapted to the brewing of porter; further, it is known to possess more saccharine matter than any other grain used in either brewing or distilling, joined to the advantage of not interfering with the season for malting barley, as this should commence when the former ceases. The summer months are the fittest for malting this kind of grain, and can be only very defectively made at any other season, as it requires a high temperature to force germination, and cause it to give out all its sweet. The following process, it is expected, will be found to answer every purpose wished for: suppose your steep to contain sixty bushels, after you have levelled it off, let on your water as directed in malting barley; you should give fresh water to your steep at the end of twenty-four hours. If it is southern corn you are malting, it will require to remain in steep seventy-two hours in the whole; if it be northern corn, it will require ninety-six hours, there being a considerable difference in the density of these two kinds of grain; the hardest, of course, requires the most water; and, in all cases, the fresher Indian corn is from the cob the better it will malt. When you have accomplished the necessary time in your steep, you let off your water; and, when sufficiently drained, let it down in your couch frame, where it will require turning once in twelve hours, in order to keep it of equal temperature; the depth of the grain should be about two feet and a half in the frame; as it begins to germinate and grow, open your frame, and thin it down at every turning, until you reduce its thickness to six or seven inches; thus extending it on your lower floor, turning it more frequently, as the growth is rapid. The vegetation of the grain, together with the turning, will by this time make the watering pot necessary; the criterion by which you will judge of its fitness for the water, is as soon as you perceive the root or acrospire begins to wither. Two thirds of your water is to be distributed over the surface of your couch for the first watering, which will require thirty-two gallons, and when turned back again, sixteen gallons for the second watering, making in the whole forty-eight gallons of water to sixty bushels of corn. This water should be put on with a gardener's watering pot, as equally as possible. Supposing this pot to contain four gallons, it will make eight pots for the first watering, and four for the second. In this stage of the operation the turnings on the floor should be very frequent, in order to keep the grain cool, as the heat of the weather, at this season, will be sufficient to promote and perfect the vegetation. The second day after the first watering, if the blade is not sufficiently grown, water again, but in less quantity, say one half. It will be now four or five days more before the couch is ready for the kiln, which will be ascertained by the blade becoming the full length of the corn. After this it should be thrown on the upper floor, and suffered to wither for a couple of days, turning it frequently; by this time the blade will have a yellow appearance, the grain will become tender, and, if tasted, be found uncommonly sweet; in this state it may be committed to the kiln, and dried in the usual way.
N. B. It will generally take ten days after it is out of the steep to perfect the malting of southern corn, and twelve days for northern.
Fermentation.
Notwithstanding that progress of improvement in the doctrine of fermentation has, in the last twenty years, far surpassed any thing in the same period that preceded it, we have still much to learn. Fermentation is the instrument or means which nature employs in the decomposition of vegetable and animal bodies, or reduction of them to their original elements, or first principles. Fermentation is, therefore, a spontaneous separation of the component parts of these bodies, and is one of those processes that is conducted by nature for their resolution, and the combination and fermentation of other bodies out of them; therefore, it is one of these operations in which nature is continually present, and going on before our eyes; this may be one reason that a very critical observance of it has escaped our attention. Fermentation brings us acquainted with this unerring axiom; that nothing in nature is lost; or that matter, of which all things are composed, is indestructible. For instance, the vinous process of fermentation, succeeded by distillation, produces ardent spirits, or alcohol, the elements of which are here described. If we pass this alcohol, or spirits of wine, through a glass, porcelain, or metallic tube, heated right hot, provided with a suitable condenser and apparatus to separate and contain the parts or products, it will be decomposed and resolved into its primitive elements, carbonic acid gas, or fixed air, and hydrogen gas, or inflammable air; the oxygen being decomposed and united with the oxygen, or vital air, into carbonic acid gas; the water of the spirit of wine being also decomposed, or resolved into its first principles as herein is stated, forms a part of the produce before mentioned.
Hence spontaneous fermentation, vinous, acetous, and putrefactive, is the natural decomposition of animal and vegetable matters, to which a certain degree of fluidity is necessary; for where vegetable and animal substances are dry, as sugar and glue for instance, and are kept so, no fermentation of any kind succeeds.
There can be no doubt that spontaneous fermentation first taught mankind the means of procuring wine and other agreeable beverage; observation and industry the means of making spirit and vinegar, the first of which is evidently the produce of art, combined with the operations of nature.
With nature for our guide, and our own ingenuity, fermentation has been made subservient to the various products we now obtain from saccharine and fermentable matters, such as sugar, molasses, grain, with which we have made wine, spirits, bread, beer, malt, &c.; which last has much facilitated our practice in fermentation, but proved the tide-ending, or point of stagnation to its further improvement. Relying too much on malted grain in the operation of fermentation, we are presented with some of the most pleasing and instructive phenomena of nature; the resolutions and combinations that are formed during the process of the vinous and acetous stages of fermentation, are interesting, beyond comparison, to the brewer, malt and molasses distillers, vintager, cider and vinegar maker, &c. The elastic fluids and volatile principles that are extricated and escape, formerly so little attended to, are now better understood. The method of commodiously saving, and advantageously applying them, and other volatile products, to the improvement of the fermenting and other fluids, will, I hope, not only form a new era in the progress of fermenting, brewing, distilling, &c. but a new source of profit, that may, in time, lead to a recomposition of those elements from which they were produced, or, at least, the fermentation of vinous fluids, vinegar, spirit, &c. by resorting to an inexhaustible source supplied by nature, of these important materials, and their application to the uses that may be made of that abundance so easily procurable, and at present so unprofitably wasted. But to continue our views to the business immediately before us, let us begin with the several products, by stating that carbonic acid gas, or fixed air, is copiously extracted from fluids in a state of vinous fermentation, and sundry mineral and vegetable substances, easily procurable, for which we have the testimony of our own senses; the same may be said of hydrogen gas, oxygen gas, &c. Presuming these positions granted, let us make a short inquiry into the composition of vinous fluids, &c. Apprehending there are but few people to whom these observations will be useful, but what will allow that all vinous fluids, whether intended for beer, wine, cider, &c. are the produce of saccharine matter, or fermentable matter obtained from the sugar cane, grain, fruit, &c. and the part which art at present takes in this beautiful process of nature, is to facilitate her operations in proportion to observation and experience, in conformity to the object in view, in making wine, beer, cider, spirit, &c.; or, subsequent to the vinous, to forward the progress of the acetous fermentation for the production of vinegar. The saccharine or fermentable matter of vegetables, consists in what is chemically called hydrogen gas, or inflammable air; carbonic acid gas, or fixed air; oxygen gas, or vital air; which last forms nearly one third part of the whole atmosphere, circumvolving our globe in which we breathe; or, more exactly, thirty-seven parts of oxygen, and seventy-three of azotic gas, are the component parts of our atmosphere, except the small proportion of undecomposed carbonic acid gas there may be found in it.
Beer, wine, cider, malt and molasses wash, and other product by distillation; spirit consists of these three elastic fluids or airs, in composition with various proportions of water. Water itself is a compound of vital and inflammable air; a proof of this, and of the indestructibility of matter, these two elastic fluids burned together, in certain proportions, and in a proper apparatus, reproduce water. By another chemical process, this very water is reducible to these two substances, vital and inflammable air; hence, we see, that all saccharine and fermentable matter, and their products, by fermentation, are composed of the same materials, and resolvable into the same elements.
It is scarcely necessary to give any definition of spontaneous fermentation, after what has been said on the subject; if it was, I would say it is that tendency which all fermentable matter has to decomposition, attended with intestine motion or ebullition, when sufficiently diluted with water, under a certain temperature of the atmosphere, the rapidity of which motion is always accompanied by an increase of temperature, or the change to a greater degree of heat generated within the body of the fermenting fluid, in proportion to the rapidity or augmentation of motion or ebullition excited. Fermentation produced by the addition of yest, or any other suitable ferment, in a fluid duly prepared, is governed by the same laws, and under the same influence of temperature, except when it is accelerated or protracted by the management of the operator, or by the changes induced by the influence of the atmosphere, rendered more or less subservient to his purposes, and produces a similar kind of spirit by distillation, possessing in common the properties of vinous spirit, or is converted to vinegar by the subsequent process of acetous fermentation, but much more productive in quantity and quality, so as to answer commercial purposes. In both spontaneous and excited fermentation, there is a similar escape of a large quantity of elastic fluid, or carbonic acid gas, with a considerable proportion of spirit, and some of the water of the fermented fluid. This gas is known to form a considerable part of mucilaginous substances, as sugar, molasses, honey, malt, and other saccharine and fermentable matter.
Although the doctrine of fermentation, as a science, does not enable us to alter the spontaneous course of nature; yet if, by the assistance of the instruments, and means recommended, we are enabled to foresee and provide for the changes induced by the alterations of the atmosphere, we can guard against the inconveniences in some cases, and make them subservient to our purpose in others; so as more securely to conduct the process in each to advantage; and that with unusual facility; complex as it at present appears: it will not only be a great improvement in the present mode of fermentation; but facilitate our progress to still greater improvements in the doctrine of fermentation. Therefore, the rule of our conduct, in these pursuits, should be to watch the operations of nature with the closest attention, and assist her when languid, and control her when too violent; that is, by spurring in one instance, and bridling in the other, and accurately and undeviatingly apply the means proposed in the manner recommended, until experience enables us to improve it; otherwise, we shall only admire, without improving or profiting by her choicest phenomena.
The motions of the planets, perplexed and intricate as they must have appeared in the infancy of astronomy, are now calculated and known with ease and precision.
Attenuation is a term not unaptly applied to fermentation, the property of attenuation being to divide, then dilute, and rarify thick, gross, viscid, and dense substances, in which some degree of fluidity is pre-supposed; it is, therefore, that kind of dilution or fluidity which is promoted by agitation, and very aptly applied to mark the progress of fermentation, which is itself the process of nature, for decomposing vegetable and animal substances under a convenient degree of fluidity; it exists in intestine motion, either spontaneous or excited, accompanied with heat, which, under certain limits, is proportioned to the vigour of the fermentation, which ends in the decomposition of one class of bodies, and the composition of another; and which may be instanced in the resolving saccharine substances into hydrogen, oxygen, and carbon, and the combining them into inflammable spirits, or alcohol, and inflammable acids or vinegar; to which may be added, the lower you attenuate, the lighter and more spiritous the fermenting fluid becomes; and that attenuation, which is the offspring of fermentation, like the parent process, has its bounds, and can only be conducted with certainty and advantage by the use of the hydrometer, thermometer, &c. In this only lies the difference between the old word fermentation, and the new word attenuation, every thing used as a ferment, or to promote fermentation, is attenuant. The tendency of the vinous process of fermentation is to evolve or disentangle the hydrogen of the fermenting fluid, and unite it, with the carbon and oxygen of the same fluid, into ardent spirit, wine, beer, or alcohol, which last is well known to be inflammable. The tendency of the acetous process of fermentation, is to involve or entangle the hydrogen and carbon of the fermented fluid, with a greater proportion of oxygen, into vinegar, which is uninflammable. The fixed air, or carbonic acid gas, so abundantly extricated during the vinous process of fermentation, which every one concerned in the process is presumed to be acquainted with, is either composed of hydrogen and oxygen, or is a composition of carbon and oxygen, on which philosophers are divided in opinion. As the result is the same with respect to the formation of wine, beer, and spirit, I shall enter into no controversial reasoning on this head, instead of which, I shall endeavour to point out the most effectual mode of saving and profitably applying it, and the other elements, in the composition of wine, beer, spirit, and acid.
As in fermentation, spontaneous or excited, there is a sensible escape of carbonic acid gas, or fixed air, it may not be improper to note, that fermentable, or saccharine matter, consists of about twenty-eight pounds of carbon, eight pounds of hydrogen, and sixty-four pounds of oxygen, reducible into fixed, inflammable, and vital air, weighing one hundred subtile pounds in toto, or that every one hundred subtile pounds of saccharine matter consists of such proportions of these airs and gasses.
Attenuation is the result of a due resolution of the fermentable matter produced by excited fermentation, which divides mucilages, resolves viscidities, breaks down cohesions, generates heat and motion, extricates the imprisoned gasses, and, by frequent commixture, promotes the action and re-action of the component particles on each other, and by continually exposing a fresh surface and opposition of matter, brings them within the sphere of each other's attraction.
As their original attraction is weakened by heat and motion, their expansion is increased by repulsion; and as they revolve, and recede from each other in this way, they are fitted, by the change in their modification, to involve each other, and from new attractions combining with each other into new substances, according to affinity, under changes induced in their nature conducive to this end, which not being exactly known, cannot at present be fully defined. In every brewing, or preparation of saccharine fluid for fermentation, the following phenomena occur: first,heatis either disengaged or fixed: secondly, anelastic fluidis either formed or absorbed in a nascent state: these two indisputable facts form the uniform and invariable phenomena of fermentation, and may be admitted as an establishedaxiom, that the proportions, extrication, and action of heat, with the fermentation and fixation of elastic fluids, during the process, are the foundation of the vinous products of the fermenting fluid. In conformity to so rational a theory, I have for many years regulated my practice, the result of which is the object of these papers. These, therefore, are the three great objects which should engage our attention; not only in fermentation, but in every similar process in chemistry, and are the fundamental principles of our doctrine.Fermentationbeing not only a decomposition of the fermentable matter, but of the water of the fluid also; and the fixed air formed during the process being composed of the hydrogen and oxygen of the fermentable matter, and the water of the fluid also, there is a perpetual decomposition and recomposition of that water, which gives fluidity to the whole mass, taking place during the continuance of the process, part of the hydrogen and oxygen of which escapes under the form of fixed air, for want of a proper substance being presented of affinity enough to absorb and combine with it into wine, beer, or spirit, or some other necessary assistance in heat, light, motion, oxygen, hydrogen, carbon, &c. or an intermedium to facilitate the formation of wine, beer, or spirit, in preference to fixed air. Fixed air, or carbonic acid gas, consists of about twenty-five parts of oxygen, and nine of carbon, devested of the mucilage and yest that rises with it. It should be recollected, that the decomposition of pyrites, the formation of nitre, respiration, fermentation, &c. are low degrees of combustion, and though it is the property of combustion to form fixed and phlogisticated airs, both the modes of doing it, and the quantity of the products, depend on the manner of oxygenating them in the changes brought about by the different modes of combustion, or fermentation in the vinous, acetous, and putrid process, which show the affinity between them.
Fermentation is a subsequentlow combustionof the vegetable oxydes or grain, that has undergone a previous, but partial combustion, something like the slightly charring, or oxydating of wood or pit-coal, by which the oxygenation is incomplete in both, and rendered more complete in the former. An ultimate combustion of the fermentable matter employed, is found only in the putrid process of fermentation, which is a final or total decomposition of vegetable and animal substances, in the actual combustion or burning of wood, charcoal, or bones.
In the vinous process we have seen the escape of carbonic acid gas; in the acetous process there is a great escape of azotic gas, or phlogisticated air, from the decomposition of the air of the atmosphere consumed in this process, which consists of about two-thirds of azotic gas, and one third of oxygen gas,[3]the oxygenous part being absorbed in the acetous process, and azotic set free with more or less hydrogen and acetic gas, proportioned to the existing heat. If the heat is beyond a certain degree, a portion of the ethereal part of the new-formed acid escapes also.
In the putrid process, the hydrogen escapes under the acriform shape of inflammable air and azotic gas, and nothing more remains than mere earth or water, or both, as the case may be, which is exactly similar to other combustions, of which nothing remains, (if we except phosphorus) but earth or ashes, with what small portion of alkaline or other salts they may contain. This alkaline matter being present during the formation of carbonic and azotic gas, absorbs, to saturation, a due proportion of them, and generatestartar.
Experience has taught us the truth or justness of this definition, and though it has brought us acquainted with the results of those three stages of fermentation, combustion, or decomposition, we have certainly overlooked the means of applying them with all the advantage they admit of in the business which is the subject of these papers, and which a little time and close observation must convince us of; and how much has been hitherto lost, with the means of saving it in future, shall be presently explained, and particularly pointed out.
In the prosecution of this design, where I may not be able to give an unexceptionable demonstration, I hope always to be provided with a practical proof, which may prove equally beneficial.
Let us now see what passes in a state of low combustion, such as may be the result of fermentation in vegetables, arising from heat, moisture, and motion, when impacted together. The most obvious occurrence of this nature is found in new hay, which, under these circumstances, for want of care and attention, often spontaneously takes fire, particularly in wet seasons.
Fermentation, being one of the lowest degrees of combustion, is here the spontaneous effect of the moist hay being impacted together, and not properly made, that is, without the superfluous juices being dried out of it, by which it retains a sufficient degree of fluidity or moisture to begin a fermentation, in which heat and motion are generated, and light, in a nascent state, extricated; these appearances accumulated and accelerated by incumbent pressure, the redundant moisture being soon exhausted, and the heat and motion increasing, the actual combustion of the mass takes place, which is much facilitated by a decomposition of the water of this moisture, and the air of the atmosphere, unavoidably insinuated between the interstices formed by the fibres of the hay, as they are impacted together into cocks, or stacks, breaks out into actual flame, orlight visible. These are no novel appearances, but such as fall within the observation of every one; and the candid maltster will acknowledge, that from the same cause, though differently produced, similar effects may, and sometimes do, happen in the malt house, in the preparation of that modern article of luxury, by which we are enabled to make malt wine; and these instances are sufficient to prove fermentation to be a low degree of combustion, and to both simplify and explain the justness of this doctrine. The malting of corn is the first stage of vegetation, low combustion, and fermentation.
From observation and reasoning on what passes before our eyes, we discover the low species of fermentation, in which the malting of corn consists, to be a low degree of combustion, which, for want of due attention, may break out into actual flame. We were always acquainted with theeffect: now reasoning on the subject brings us to a knowledge of the cause.
To any one well acquainted with the nature of fermentation, it must be manifest, that the malt distillers have paid more attention, and made greater progress in the improvement of the process than any other class of men interested in the success, though far from having arrived at theirne plus ultra.
The introduction of raw or unmalted corn; the close compactness of their working tun, or fermenting backs; the order and progressive succession with which they conduct the process; and the pains they necessarily take to arrive at a perfect attenuation, by a long protracted fermentation, with the early conviction of a reward proportioned to their diligence, and the success attending their best endeavours, when not frustrated by intervening causes, must be stronger inducements with them to delight in this instructive process of nature's formation, than with the brewer, who has not these immediate tests to encourage his labours, which the others daily derive from distillation, and which so quickly and uniformly terminates their hazards and success. The principal object in their view being a high and deliberate attenuation, with a full vinosity, without any further regard to the quality or flavour of their mash, as the combination of these qualities alone produces the required strength, in the cleanest manner.
The brewer's cares are many, and of longer duration: he is the vintager of our northern climates: his porter or ale should be an agreeable malt wine, suited to the palate of the district or neighbourhood he lives in, or, ultimately, to the taste of his customers. The time he has allotted himself for attenuation was first founded in error, derived from ignorance of the subject, and slavishly continued by that invincible tyrant, custom. Hurry marks the progress of his fermentation, which can only be corrected by his speedy mode ofcleansing, and the consequent but necessary perishing of a part. He must begin with more accuracy at the mash tun than the malt distiller, as it is there he must not only regulate the strength, but, partially, the flavour and transparency of his malt wine. His object does not end with the malt distiller's, nor, like his, concentre in one focal point, the solution of the whole of the farina of the plant or grain employed, regardless of milkiness or transparency; he must carefully take the heats of his liquor, so as to solve and combine the qualities he has in view; which, if he misses in the first mash, is partly irremediable in the succeeding ones. His cares do not end here; independent of the minutiæ of fermentation and cleansing, he has the flavour, fining, and bringing forward of hismalt wines, nearly as much as the strength, to consider and employ his attention.
It will scarcely be supposed that I would make these observations merely with a view of drawing this comparison, though even it might throw some light on the subject, without an attempt at supplying the defects pointed out, and remedying the evils represented.
When the carbonic acid gas, or fixed air, so often mentioned in these papers may be rendered subservient to part of the improvements I have in view, and which is the constant, abundant, and uniform result of low combustion, or vinous fermentation, in proportion of thirty-five pounds weight to every hundred of saccharine or fermentable matter, fermented in a due proportion of liquor, or water; from the decomposition of which last, and the absorption of its oxygen, it is principally obtained.
We have previously seen that one hundred pounds of fermentable matter consists of eight pounds of hydrogen, twenty-eight of carbon, and sixty-four pounds of oxygen; we have also seen that about thirty-five pounds of carbon is extricated and detached from this quantity of fermentable matter, properly diluted in water during fermentation; allowing the usual quantity of spirit at the same time to be formed by the process of this superfluous carbon, (as it now appears) must come principally from that decomposition of the water of dilution, and not from saccharine matter employed, which contains altogether but twenty-eight pounds of carbon, the whole of which must necessarily go to the formation of the fifty-seven pounds of dry alcohol produced.
But not to descend too deeply into particulars that might lead into discussions not absolutely necessary in this place, let us take the produce of ten gallons of ardent spirit, at one to ten over proof. We here find that much more carbon has been generated, and given to the atmosphere, than went to the composition of this quantity of spirit, independent of the large quantity of alcohol dissolved in, and carried off by it, in its flight as before observed.
Allowing the average quantity of fermentable matter in a quarter of malt, barley, or other grain, to be only seventy-five pounds, then four quarters will be equal to three hundred subtile pounds of raw sugar; or eighty quarters of the one will be equal to six thousand pounds of the other, or three tuns weight of unadulterated molasses.
If we estimate the superfluous carbonic acid gas of this quantity of materials at only twenty-eight pounds per hundred, that will be sixteen hundred and eighty pounds dissipated during the fermentation, which is a loss, on every brewing of this quantity of materials, of upwards of forty-one gallons of spirit, of the strength of one to ten.
What is computed here in spirit, may easily be applied to wine, porter, beer, ale, sweets, &c. In barrels allowing three gallons and three quarts of spirit per barrel to the former, and four gallons per barrel to the latter, which gives eleven barrels and three quarters of the one, and ten barrels and a quarter of the other, lost on each brewing of eighty quarters of malt, or the average of that quantity of other materials, by the mismanagement of the fermentation in one point only.
It must appear evident to every person capable of investigating this calculation, that every six or seven pounds of carbon, fixed upon each quarter of malt, or other materials, there will be an augmentation of gravity or strength on this number of quarters, of ten or twelve barrels each brewing; that is, every six or seven pounds of this fugitive carbon that we arrest and fix in the fermenting fluid, as a component part of the subsequent produce, by presenting the requisite portion of oxygen and hydrogen, for the purpose within the sphere of each others attraction, we increase our strength in the before-mentionedratio. It is of little moment whether this redundant gas comes from the water of dilution or from the fermentable matter, as under, if we can by any means turn it to account.
We have presumed the average quantity of fermentable matter at seventy-five pounds per quarter; this must be evidently on the best goods; this will give us a length of three barrels per quarter of malt of eight bushels, of twenty-five pounds per barrel, specific gravity. Suppose the apparent attenuation of these goods to be nineteen pounds, the transparent gravity will be six pounds per barrel, viz.
It may be said that nineteen pounds is the real attenuation, and the yest and lees produced is part thereof, as the fluid, or beer, in a state of transparency is but six pounds per barrel specific gravity, and it may, in some degree, be allowed to be so, as there is really so much gravity lost during the process of fermentation. If we multiply thirteen pounds eight ounces, which I have called the real attenuation, by four, we shall find the result to be fifty-four pounds, which is nineteen pounds more of superfluous gas upon four barrels of worts, of twenty-five pounds gravity each, than is extricated from an equivalent quantity of saccharine matter; that is, from one hundred pounds of raw sugar or one hundred and twelve pounds of molasses, and their respective waters of dilution, when the yest and lees do not exceed five pounds eight ounces per barrel. This may be truly called an analysis of the fermentable matter, giving the component parts tolerably exact; though much depends on the management of the fermentation, and the subsequent cleansing. By this analysis it appears, that the mucilage of malt, or grain, gives out more gas than the mucilage of sugar; and leaves a doubt on the mind whether to adjudge the superfluous gas to the fermentable matter, or to the water of dilution, or partly to both; but so it is, that these are the products, whatever source we derive them from, and there is no denying facts. The yest first added is not brought into this account.
There is a great similarity of appearance between the two species of low combustion, fermentation and respiration. Fermentation, like respiration, is the spontaneous effort of involuntary motion to decomposition; and in the fermenting mass, as in the animal system, it raises the temperature of both above that of the surrounding atmosphere: that is, it is the cause of heat and involuntary motion, both in the fermenting mass and in the animal system; and, like slow combustion, consumes both, and resolves them into their first principles, from which tendency the latter is constantly withheld by the ingesta, fuel, or food, thrown in. I am well aware I must not carry this reasoning any further.
Deep investigation may be thought not to be the object of our research; but we must always have two things in view in inquiries of this nature; indeed, in every pursuit of useful knowledge, where, like the present, it is connected with the first principles, to pursue the winding path of nature, through all her meanderings, up to the ultimate source of these elements, which are the instruments of her operations; and when we are favoured with a knowledge of these, either as the reward of laboured assiduity and attention, or the result of chance, to copy the original as close as we can.
I know I shall be justly accused with tautology. I must plead guilty to the charge, not having leisure to apply the pruning hook of correction. The misfortune is, that new doctrines must appear in a new dress, by which they wear the garb of novelty, though, with respect to first principles, there is nothing new under the sun; yet the application of these principles might have remained in oblivion for ever if not called into action. The man who in an age calls them into action, and beneficially applies them for the good of that community of which he is a member, may be virtually, though not literally, called the discoverer of a principle. The man that projects, and the man that executes a voyage of discovery, have superior claims to the man at the mast head who first cries out land. The new turn that the discoveries of modern philosophers has given to natural philosophy, requiring a change of names as well as system; unusual words are unavoidably introduced to express new terms of science, which gives a different character and fashion to the whole, that I should have great pleasure in avoiding, were it possible, which it obviously is not, finding it easier to glide down the stream than oppose its torrent.
Notwithstanding that I have calculated upon nineteen pounds only of twenty-five pounds per barrel of fermentable matter being attenuated, and have even in that quantity included five pounds eight ounces of lees and yest, (the least quantity produced,) such calculation must not be admitted to preclude the practicability of attenuating almost every particle of fermentable matter, and replacing it with an equivalent particle of spirit, if that spirit which is now carried off by the avolation of the fixed air, is, agreeably to my proposal, either arrested in its flight, or filtered, after its escape from the guile tun and cleansing vat, by the proper apparatus.
Having in a former part of these papers observed, that attenuation may be carried too far, it may be necessary for me to reconcile these seemingly opposite positions, which should be understood in this way: When the quantity of fermentable matter, suspended in a barrel of worts, intended for beer, or ale, is from five to ten pounds more than twenty-five pounds per barrel, every particle of it may be safely attenuated, as the quantity of spirit generated will be sufficient to preserve the beer, or ale, for any requisite length of time, provided it has been properly hopped, &c., or in lieu thereof, received certain other additions to improve its vinosity, strength, and keeping; when the quantity of fermentable matter in worts is from five to fifteen pounds per barrel less than twenty-five pounds, the height of the attenuation ought to be limited on keeping beer and ale; the spirit generated being insufficient to preserve so much fermented fluid in a drinkable state for any length of time, with the usual additions only, even during the summer heats of our own climate; and if so, it is totally unfit for either exportation to warm latitudes, or for keeping at home.
For the right understanding of these observations, we should consider that the unattenuated fermentable matter is perpetually furnishing a gradual supply of fixed air and spirit, by means of the imperceptible fermentation always going on in vinous liquors.
Weak beers and ales fret and spoil very soon in warm weather, which proceeds from the development and avolation of their fixed air; strong beers and ales have their limits under the same influence of heat, time, change of the atmosphere, &c., and owe their preservation to two things, viz. to a due proportion of fermentable matter unattenuated, or the quantity of spirit they contain; as under these circumstances they are either preserved by the spirit already formed, or that continually supplied by the spontaneous decomposition of the fermentable matter they contain, slowly developing and yielding a fresh supply of air and spirit; hence beer and ales, not too highly attenuated, derive strength and spirituosity from age, when properly stored or cellared, and duly secured from the changes of the atmosphere.
These observations are applicable to sweets, or made wines, and to those which are the produce of the grape, the progress of fermentation and attenuation being (or ought to be) interrupted in them by racking off, which is similar to cleansing in beers and ales: and in Madeiras, and other dry wines, the incipient acidity is corrected and restrained, by proper additions introduced in the early part of the process, and with others of similar effect when the wines are making up, either for use or exportation.
We may gather from these observations, that worts attenuated for beer or ale, to the decomposition of all their fermentable matter, that is, attenuated so high, or so low, that their specific gravity is reduced to the standard of common water, and from that to the degree of levity spirit is known to give to water, in the proportion to the quantity added, and left to the preservation of the spirit formed, they have little or no auxiliary assistance from their original products, already exhausted by the highest or completest attenuation obtainable; an important circumstance, always to be attended to, particularly by those who affect an unnecessarily high attenuation!
The intelligent brewer may, by the assistance of these observations, form a most accurate rule for the regulation of his future conduct in the management of fermentation, according as his beer or ale is to be weak or strong, or for present use or long keeping; for the accomplishment of which, the use of the hydrometer and thermometer claim his peculiar attention, and will undoubtedly answer his expectations, when joined to the certainty he is now at, of knowing when he is, or is not, to expect the development of fixed air and additional spirit, by which he can govern himself accordingly.
These observations lead to a removal of the difficulties that lay in the way, and, at the same time, suggest a mode of applying the present, or of constructing a futurehydrometer, for ascertaining the strength or the quantity of the vinous spirit in beer, wine, ale, and other fermented fluids, which has long been a desirable object.
The distiller, having none of these niceties to attend to, is governed by the ultimate extent of the attenuation the worts, or wash, is found capable of, and which is both assisted and protracted by its superior density, in its progress from specific gravity to specific levity, if such an expression is admissible.
Fermentation, begun in a fluid more or less saturated with saccharine or fermentable matter, the process is finished sooner or later, and usually in proportion to the degree of saturation, and the being conducted with more or less vigour under a well regulated temperature; for the more a fluid abounds with this matter, the grosser and denser it must necessarily be, and the longer will the attenuation be protracted; the longer it is protracted, in air-tight vessels, and in a healthy and vigourous state of decomposition, the more spiritous and strong will that wash turn out, and the greater the produce of spirit in distillation; hence, it is both protracted and assisted by its density.
A languid may be truly called an unhealthy decomposition, it being productive of diseases common to misconducted fermentation, acidity, putridity, and lack of spirits, with a tendency to precipitate and burn upon the bottom of the still; hence, all the decompositions are confounded together, as in spontaneous fermentation.
The formation of acidity during the process, is not of that injury to the distiller that it is to the brewer, nor is this recent acidity vinegar, as has been supposed by some chemists, but the incipient state of combination of resolving elements, whose particles are in that juxtaposition best suited to absorb developing hydrogen in a nascent state, and intimately to combine with it into vinous spirit, the approximation to which is promoted by time and incumbent pressure: these positions shall be explained as I proceed.
The reason that putridity is so rarely discovered in excited fermentation, is, that it is usually counteracted by the previously evolved acidity, and corrected, but not saturated or neutralized; for, were that the case, the putrid could not immediately succeed the acetous process in the same fluid, nor exist together, as they are known to do in declining beer, vinegar, &c.
The reason that acidity is not more frequently observed and attended to than it is, is because of its being sheathed or covered by the unattenuated sweets, or fermentable matter of the wash that remains undecomposed.
On the other hand, when acidity is very prevalent, it may be mistaken for unattenuated fermentable matter, acidity increasing the density and specific gravity of the fluid.
Putridity, from the avolation of its products, promotes levity, and that in proportion as its increase surpasses that of the general acid; and it is not until the action of the acetous becomes languid, that the putrid process gains the ascendency, when it is then difficult to overcome.
Although these observations may show how the hydrometer, or its use, in unexperienced hands may be baffled, they both distinguish and explain the value of its application; they do more—they elucidate the doctrine of fermentation, and illustrate the goodness of Providence, who has made nothing in vain, but provided nature with its own resources for conducting every operation in the great plan of the universe with uniform and unerring security.
In the decomposition of fermentable matter, either by combustion or fermentation, (which I have defined to be synonimous,) a portion of inflammable air, or hydrogen, is first evolved; secondly, another portion of inflammable air, united with pure air, or oxygen gas, evolves under the form of fixed air; this is the constant and uniform phenomena of these decompositions, and are progressively going on from the beginning to the end of the fermentation, while there is any fermentable matter to attenuate. A due portion of oxygen uniting in a nascent state with a correspondent portion of inflammable or hydrogen, and fixed air, forms the spiritous particles dispersed through the fermenting fluid, which create vinosity, and constitute it wine, beer, or wash.
During which, so great is the avolation of fixed air, (as we have seen,) that much of the ethereal part of the new formed, or, rather, the scarcely-formed spirit, is carried off with it in a gaseous state. This is much assisted by the agency of the atmosphere, which is the solvent and receptacle of ethereal products, whose affinity for them must be as great as it is perfect and immediate—which demonstrates the necessity of having air-tight vats. When we consider the composition of the atmosphere, and that it owes its formation and existence to this cause, and, thereby becomes the menstruum of all created matter, we may be better able to understand the composition and formation of vinous spirits, and, by closely copying the original, more successfully imitate nature. We have seen that the principal phenomena in fermenting fluids is a brisk intestine motion of their parts, excited in all directions with a loss of transparency, or a muddiness, a hissing noise, the generating of gentle heat, and an exhalation of gas. This heat, we must now observe, is always very sensible before the extrication of any gas. We have adverted to the similarity existing between respiration and fermentation, which is remarkably so in the equality of heat produced in both in a healthy state of either, and which seldom exceeds ninety-six degrees of Fahrenheit's thermometer; but there are instances of their being much higher in both, without producing much injury to either. Instances of this could be adduced at home, without referring to warmer climates of the East and West Indies, where the temperature of the atmosphere is so much higher than with us; and that the temperature of the fermenting fluid, when at its height, always exceeds that of the surrounding atmosphere in these latitudes, which makes the similarity still stronger between these two decomposing processes. This is a general and just remark; but, in order to regulate it by practical facts, we must name the medium standard of heat, which rarely exceeds eighty-five degrees with the brewers; this is the medium of seventy-four and ninety-six degrees; but the medium heat is not unfrequently up to ninety-six degrees in the distiller's fermenting backs of Great Britain. Much depends on the degree of temperature the fermentation is pitched at: here, nothing is spoken of but the cleansing heat with the brewers, and the medium heat with the distillers.
For the maintenance of combustion, the free access of air being necessary, an objection may be raised to air-tight vats, as unfit to carry on this process in, to the exclusion of external air; which objection may seem to gather force from the compression it occasions of the fixed air on the decomposing fluid, which is allowed to extinguish active combustion. I must acknowledge these are formidable objections to my definition of low combustion, but I by no means find them unanswerable.
The aptitude of new hay, malt, and other vegetable matters, to spontaneous combustion, when impacted together by incumbent pressure, and a certain degree of moisture, should be recollected; and that this tendency is not destroyed by excluding the admission of external air, but by quickly cooling and dividing the impacted hay.
The great quantity of oxygen, or vital air, both in the water of dilution, and in the fermentable matter, with which the fluid is more or less saturated, should be also recollected, which is about eighty-five parts in the former, and sixty-four parts of one hundred in the latter.
Though, in an unelastic or fixed state, it is one of the properties of combustion to disengage and render it elastic, great part of which, during the low combustion which it supports, and in which heat is visible or perceptible, and light in an invisible state developed, three parts of this oxygen, with about one third of its weight of carbon, is converted into an elastic state, under the form of fixed air, that separates from the decomposing mass; a circumstance attending also on the combustion of coal and other combustible substances during their decomposition by that process, which supported in them by the external air of the atmosphere, where heat and light are both visible from the intensity and velocity of the combustion; and wholly invisible in the former, not from exclusion of external air, but from the length of time elapsed in low combustion; the one being performed instantaneously, and the other taking several days from its decomposition. Although fixed air is known to extinguish a lighted candle, and destroy animal life, that is, to be equally unfit for the combustion of inflammable bodies, or the support of animal respiration, it is also known to be as successfully employed as atmospheric air, or even dephlogisticated air, to melt glass, &c., when applied to the clear flame of a wax candle, by passing a current of it through a blow-pipe, to direct that flame on the glass to be melted.[4]
This will not be so much to be wondered at, when we consider that the proportion of vital air in fixed air is as twenty-seven to nine, and in atmospheric air, the proportion of azotic gas or phlogisticated air, to vital air, is as seventy-three to twenty-seven; therefore, the former contains three fourths of vital air, and the latter little better than one fourth; but the fixed air is in a combined, and the phlogisticated air in an uncombined state. Among the processes made use of by nature for the decomposition of vegetable and animal substances, fermentation, or low combustion, is a principle one. Air, in a fixed or unelastic state, may be as necessary here as air in an elastic state is known to be in the active combustion of inflammable bodies. Chemists and philosophers are no strangers to two sorts of combustion, one in external air, and the other in close vessels.
But this is not the combustion alluded to in fermentation, where all the requisites for complete decomposition is to be found independent of contact with the atmosphere; here one part is oxygenated at the expense of the other, and the other disoxygenated in favour of it.
Nor does the solution, or decomposition of metals by acids, the combustion of inflammable and vital air for the production of water, stand in need of external heat or fire, any more than the low combustion in which fermentation consists for the production of spirit, beer, or wine, than that generated by the self-operation of its own temperature; similar to this is the self-animating principle or power with which nature has endowed the animal body of generating its own heat by respiration.
In fermentation, the caloric, or matter of heat, which is plentifully disengaged by the condensation of oxygen, is prevented from breaking out into flame with the condensing hydrogen, from the presence of affinities in the fermenting mass, ready to absorb and fix them into vinous spirit, ale, beer, &c., with the other component element, carbon; by which they are too instantaneously taken up and fixed, to amount to more than bare ebullition, and pass at once from an incipient state of elasticity, to a fixed and non-elastic one, while the redundant heat, which would otherwise appear, is taken up and carried off by the abundant formation of carbonic acid gas, which requires so great a quantity of caloric to render it permanently elastic, as not only keeps this sort of combustion under ignition, but much below the degree of heat at which the accumulating vinous spirit could be raised to the evaporable or distilling point, though capable, as already observed, of detaching a considerable portion of it with the volatile gas, and of the water of solution, or the water of composition recently formed from the present attractions in its most volatile and incipient state of formation; both which we have seen ascend with the fixed air extricated, partly in a combined, and partly in an uncombined state.
One part of hydrogen is sufficient to saturate and fix above five of carbon, and they require nearly sixteen parts of oxygen to complete their formation into alcohol, while the water of dilution undergoes a proportionate decomposition and recomposition, to assist the resolutions and combinations, and support the admirable equilibrium preserved by nature.
At the same time that the extreme levity of the hydrogen gas accounts for the great quantity of heat which it holds in combination, and the high temperature requisite to effect its decomposition, and that such is its capacity for heat, that though combined with oxygen and water, it still possesses the property of absorbing a great deal more. It is this property that renders aqueous vapour lighter than atmospheric air in which it ascends; yet we have just now demonstrated the resolution and combination of hydrogen gas, and oxygen gas, both extricated from the fermentable matter and the water of dilution, and their formation into spirit, &c., at a temperature not many degrees above that of the incumbent atmosphere, and no higher than that excited by respiration in the animal system.
In which we have shown the vegetable oxyde, (saccharine matter,) when reduced by the admixture of water, to form the worts or wash, to be a carbonated hydrogenous fluid, containing the elements of wine, beer, ale, spirit, &c., and the mode of producing them under circumstances conducive to their formation; these are motion, heat, pressure, and mutual attraction, called into existence by a species of low combustion, or fermentation, somewhat similar to respiration. In which the materials, the products, and the liberation of caloric are ultimately the same, whether the operation is attended by visible fire from the velocity of action, or weak incalescence from the slow progression of its motion; in which the component elements are continually assuming a gasseous form, and as constantly losing it by the force of mutual attraction for each other. No sooner is the equilibrium broken, in one instance, by their gasseous appearance, than it is restored by their condensation, and the heat liberated by the latter taken up by the former, by which the equilibrium is preserved; in this consists the increase of temperature above that of the surrounding atmosphere, accompanied by the discharge of fixed air; to fix, and advantageously apply which, shall be the next consideration; and, by an accurate imitation of the modification employed by nature, to render the fermenting fluid so much the stronger by such fixation. To accomplish which, we must advert to what has been delivered in the preceding pages, particularly to the proportions in which the equilibrium preserved by nature consists, and exactly to her manner of combining them in sugar, malt, and other saccharine matter, her mode of breaking this equilibrium, or decomposing them by fermentation, and recombining them into wine, beer, &c., and by the same process restoring the equilibrium.
It cannot be doubted, but that, in the investigation of the acetous process of fermentation with the attenuation we do the vinous, they will mutually reflect light on each other; in which it will come out that wine, beer, ale, vinegar, spirit, &c., are not the only commercial preparation to which the doctrine of fermentation, or low combustion, may be advantageously applied, but also to others, that are perhaps equally important and productive.
The cleansing being at the meridian, or greatest temperature of the heat of the fermenting fluid, and the object of that cleansing being to reduce the heat, and thereby allay the violence of the fermentation, by which an immediate decomposition takes place, the lighter impurities buoyed up to the top of the fluid flows off with the yest, while the heavier dregs descend to the bottom, and the fermentation gradually declines as the cleansing draws to a conclusion, and the fermenting fluid forms a turbid heterogeneous mass, very perceptibly approaching towards a transparent homogeneous fluid in its progress to a drinkable state.
In laying out a brewery, the air should have free access to the coolers on all sides, under and over; cleansing vessels should be similarly situated, and, if avoidable, the coolers should not lay immediately over them, to raise their temperature, which should not be many degrees above that of the atmosphere, at temperate, which is fifty-two degrees; but the descent from the cleansing heat (seventy-five to eighty-five) should be progressive, that is, not sudden. A sudden chill would precipitate the grosser, and diffuse the lighter dregs throughout the fermenting fluid, which should be thrown off from the surface in cleansing; this would retard the fining, and empoverish the beer or ale; while the mode recommended will be found to promote transparency, and give strength and body, that is, fullness and spirituosity. In general, the cleansing commences too soon for the strength and quality of the goods, particularly for porter, since the introduction of a greater proportion of pale malt than formerly used; a more perfect fermentation is now requisite to keep up the genuine distinction in that flavour of porter from ordinary beers and ales, which, since the change oflengths, has much declined, though the only characteristic quality that gives it merit over other malt liquors—an object that deserves consideration in this great commercial branch of trade, and source of national wealth, where the loss of distinction will be the loss of trade. The rough, astringent, thirst-creating smack is the produce of the brown malt, and a well conducted fermentation. The porter now brewed can no more bear the sudden chill of a cooling atmosphere in the barrel cleansing, without too immediate a condensation and separation of its parts, than it is able to sustain the quick changes of a warm atmosphere, without an immediate tendency to acidity. As things now are, either extreme can only be avoided by a more attentive advertence to the mode ofcleansing, so as to prevent a predominant tendency to either by adopting the means proposed, or such other, on the same principles, as are equally likely to preserve the quality, increase the strength, promote transparency, and avoid acidity. I know it may be urged by the most able brewers, that a high and rapid fermentation in the cleansing is a principal cause of that flavour for which porter is distinguished; that this kind of fermentation leads to a more perfect attenuation; and some of them may, with great truth, add, a perfect attenuation is the genuine mode of early bringing beer forward. This I most readily grant; it is the doctrine I wish to inculcate. The greater gravity of keeping beers, preserves them in amild state, while their spirituosity prevents acidity. The flavour of the colouring matter now in use, nor the change it induces, is not, by any means, adapted to preserve the genuine flavour of porter, or compensate for that made in the change of malt; a change I by no means condemn, with respect to the malt; but however advantageous to the length, we must not altogether give up flavour, while we may equally as well, and indeed much better, preserve both by a due admixture of each sort of malt, and with suitable additions and proper correctives in the process or preparation of porter, both salubrious; as by the subsequent mixture of stale and mild beer, before sending out, or, afterwards, by drawing them from different casks into the same pot, when on draught, to suit the palate of each respective customer.
I hope it is by this time understood, that my views are to raise theProcess of Brewingabove the vulgar error that tyrant custom has entailed on it, and by the free exercise of the brewer's abilities, both in a scientific and tradesman-like manner, so as advantageously to preserve flavour and quality, with almost any proportions of every sort of malt he may occasionally be obliged to use.
The world is continually exclaiming thatexperienceis better thantheory. This is very true; for example, he who has had a very long experience, may, in general, perform operations with tolerable exactness; but this he undeviatingly does by certain stated means, without any deeper intelligence of the process. I would, with Mr.Chaptal, compare such a man to a blind person who is acquainted with the road, and can pass along it with ease, and perhaps even with the confidence and assurance of a man who sees perfectly well, but is at the same time incapable of avoiding accidental obstacles, of shortening his way, or taking the most direct course, and alike incapable of laying down any rules which he can communicate to others. This is the state of the artist of mere experience, however long the duration of his practice may have been, as the simple performer of operations.
Brewing, fermenting, distilling, &c., are branches of commercial chemistry, that generally challenge the attention and secure the protection of those governments that constitute them sources of revenue and trade. Chemistry is as much the basis of the arts and manufactures, as mathematics is the fundamental principle of mechanics. In the process of brewing porter, ale, threepenny, &c., to be subsequently treated of, the practical minutia of fermentation and attenuation shall be circumstantially laid down in each, so as to account for, and distinguish the variety of flavour, &c., assignable to eachcause effectedby the different modes of treatment.