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identical with an acid found in the bodies of ants, and amylic alcohol into valerianic acid, identical with an acid existing in angelica root and several other plants.
Throughout the remainder of this article, the term alcohol will be used in its ordinary sense, that is, to signify vinous spirit, the product of the distillation of a fermented liquid.
Sources of Alcohol.-Experimental science has demonstrated that starch-sugar or grape-sugar is the only true source of vinous alcohol ; that it is from a liquid consisting essentially of a solution of one of these sugars in water that alcohol can alone be obtained.
Grape-sugar and starch-sugar are substances of exactly similar composition and properties. The former may be extracted in large quantity from the juice of sweet grapes, and from honey, of which it forms the solid, crystalline portion. It is abundantly contained also in various ripo fruits besides grapes, such as plums, cherries, pears, &c. The general name, grape-sugar, is given to the sweet matter derivable from each of these sources, because of its identity with the species of sugar found in grapes. Starch-sugar is so called from its being artificially produced by boiling starch with dilute sulphuric acid, or by digesting it with the diastase of malt as in the process of brewing. The product thus obtained cannot be in any respect distinguished from grape-sugar.
The combustion of wood in close vessels is the only known means of procuring wuod-spirit economically and in any quantity, and on the other hand, the fermentation of solutions of starch or grape-sugar supplies the only availablo means of obtaining alcohol on the large scale. It is true that an eminent chemist, M. Berthelot, has pointed out a method of producing alcohol synthetically, that is, by putting togetber its constituents, as opposed to the method of deriving it from the decomposition of sugar. The process adopted by him was to agitate olefiant gas-one of the products of the destructive distillation of coal, and always present to a large extent in common coal gas-with strong sulphuric acid until a considerable volume of the gas became absorbed, and then to dilute and distil the mixture. He succeeded in this way in obtaining, with tolerable facility, small quantities of weak alcohol.* But, the amount of scientific skill required in the execution of such an experiment, together with the expense, trouble, and uncertainty attending it, deprives it of any practical value beyond the illustration which it affords of the possibility of forming an organic compound by union of its elements.
It may, at first, be thought incorrect to state, that alcohol cannot be immediately derived from any other source than the decomposition of starch-sugar, when it is well-kvown that rum is prepared by fermenting ordinary cane sugar or molasses, and also that the British distiller frequently employs one or other of these materials in the fabrication spirits.
But, the explanation is, that cane sugar or molasses, the latter of which consists in a great part of uncrystallizable cane sugar, is incapable of undergoing fermentution and yielding alcohol, until it has been changed into grape-sugar.
This is effected by the agency of a ferment, such as yeast, prior to the setting up of the direct fermentative process, which then transforms the altered sugar into alcohol and carbonic acid gas.
A proof of the reality of this primary action of the yeast is furnished in the fact, that the density of the cane-sugar wort regularly increases for a short time after the addition of the yeast, instead of at once
A report which was at one time circulated to the effect, that alcohol had been manufactured on an extensive scale at a gas factory in France, from one of the products of the combustion of coal originated probably in an exaggeration of Berthelot's discovery.
decreasing, as is the case with malt or grain wort, the sugar of which existing already as starch-sugar needs no preliminary modification. The cane-sugar, under the influence of the yeast, takes up and combines with an atom of water from the wort, and thus passes into the condition of starch-sugar. Every 171 lbs. of the cane-sugar present in the wort combines with 9 lbs. of water, forming 180 lbs. of starch-sugar, and as the water thus appropriated, and now forming part of the solid matter present, exists in a more condensed form than before, the gravity of the liquid must rise, while its quantity decreases. When a large proportion of yeast is used to excite the wort to speedy and vigorous fermentation, the increase of gravity produced by the change into starch-sugar is soon concealed under the fast diminishing density resulting from attenuation, but if an officer will take the trouble, as opportunity occurs, to test the gravity of cane-sugar wort in about an hour after his first account at the time of declaration, he will find that a marked increase of gravity has taken place, amounting as a rule, if it could be accurately observed, to as much as two and three degrees on the saccharometer.
It thus appears that cane-sugar, when fully fermented, yields more than its own weight of alcohol and carbonic acid gas, inasmuch as 171 lbs. of
cane-sugar, with 9 lbs. of water, form 180 lbs. of starch-sugar, which quantity of starch-sugar becomes resolved into 92 lbs. of alcohol and 88 lbs. of carbonic acid gas, making together the entire weight of the sugar decomposed.
Pure starch is, of course, never used by the distiller for the production of spirit, while he can avail himself much more profitably of the various kinds of grain, all of which contain starch as their principal ingredient ; nor would it servo his purpose to go through the preparatory process of separating the starch from these or other substances, and then diffusing it through water, when by the operations of grinding and mashing, the raw material can be made to furnish a starchy liquid, which, in contact with the diastase of malt and under proper conditions of temperature, yields a solution of sugar fit for immediate fermentation.
Even if pure sturch were an economical material, the wort prepared from it would not attenuate thoroughly without the repeated addition of large quantities of yeast, a fact accounted for by the absence from the pure starch wort of any portion of gluten or albuminous matter which would supply the yeast with the elements necessary to its reproduction. The use of much yeast imparts a disagree. able flavour to the wash, besides being in other respects objectionable, and in places remote from large breweries, the carriage of the yeast is a source of considerable expense ; gluten or albumen cannot be conveniently obtained in a soluble form except from malt or grain wort itself, and for these reasons it is plain that it would be in every way disadvantageous to the distiller to prepare his worts from pure starch.
On the same account, pure cane sugar is by itself ineligible as a material for the production of spirit. Although it is true that starch sugar alone furnishes the component parts of alcohol, yet as has been already stated, the presence in the wort of a sufficient quantity of dissolved gluten, albumen, or some other nitrogenous substance, is essential to the propagation of the yeast, and the satisfactory decomposition of the sugar.
Distillers' Materials ; Varieties of Spirit, &c.—The traders called by the excise, distillers, are of two classes :
1st. Those who manufacture spirits from malt only. The produce in this case is delivered for sale and is for the most part consumed as a beverage without any admixture or change of quality except that of a reduction of the strength with water. 2nd. Those who distil from materials consisting of various kinds of raw grain, with the necessary addition of a small quantity of malt, and occasionally from sugar, molasses, and treacle, either separately or in combination with malt and grain. The spirit so derived is applied to several purposes. A portion of it is diluted and consumed without further change as a beverage like pure malt spirit; it is a common practice, however, amongst dealers, to blend the less expensive raw grain or sugar spirit with a little highly flavoured malt spirit, and to sell the mixture under the name of " malt spirit.” Some of the raw grain or sugar spirit is disposed of at a high strength as « spirits of wine" for use in the arts and manufactures, either in an unmixed state or when converted into methylated spirit. But the great bulk of the raw grain spirit made in this country is supplied to the traders styled Rectifiers, who, by certain processes which will be briefly described in a subsequent article, purify the spirit and then . convert it into the liquors known as Gin, British Brandy, Cordials, &c.
Sugar or molasses spirit is objected to by the majority of rectifiers. They find that owing to its peculiar and persistent flavour, which it is impossible to remove without the loss attendant on repeated rectifications, it cannot be used with advantage in the making of gin or compounds.
Ordinary raw grain spirit, such as that obtained from barley, oats, and wheat, with the admixture of a little malt, is the best suited to the purposes of the rectifier.
Within the last few years, several attempts have been made in various parts of England, to extract by a peculiar process, a marketable spirit from beet-root, before employing the latter as food for cattle. The idea entertained by the projectors of this enterprise was, that the value of the spirit when rectified would suffice to defray the cost of materials and of manufacture, while the beet-root itself would be improved as a cattle food by the operation it had undergone, and would yield a large profit to the farmer. But from the results of the experiments that have been carried out up to the present time it does not appear likely that the scheme will prove successful. The amount of produce from a given weight of the root, -not exceeding 164 proof gallons per ton, under the best management,—is much smaller than was anticipated, and the spirit, however carefully distilled and rectified, possesses so disagreeable a taste and odour as to render it quite unfit for use as a beverage, and only available for the preparation of methylated spirit.
The manufacture of the kind of spirit derived from malt only, and sold under the denomination of « malt whiskey,” or “small still whiskey” is almost wholly confined to Scotland, although there are in that country several large distilleries which produce grain and sugar spirit exclusively. « Grain spirit,” or sometimes, “ raw grain spirit,” is the term employed to designate the spirit obtained from a mixture of malted and unmalted grain, while the term “malt spirit” is applied distinctively to the spirit manufactured from malt unmixed with grain or other materials.
In England, the few distilleries now at work produce grain or sugar spirit only, the greater part of which is disposed of to rectifiers. In Ireland, a little malt whiskey is manufactured, but the majority of the distillers supply grain spirit of fine quality for consumption as a beverage, only a small portion of it being sold to rectifiers.
Grain spirit, when it has attained a considerable age, is greatly esteemed by some persons and even preferred to malt whiskey, but when new, it is harsh and
fiery. Sugar or molasses spirit is almost undrinkable when recently distilled, but by keeping it is said to improve and become exceedingly mild and palatable.*
The use of sugar or molasses, however, is seldom resorted to by distillers, except when grain happens to be scarce, or when they are working to supply methylated spirit makers. For this purpose, it matters very little as to the quality of the spirit so long as it can be obtained at a low cost. A mixture of grain and sugar, or grain and molasses, has been found to ferment better and to yield a finer spirit than sugar or molasses singly. A syrup imported from the West Indies and called cane juice or “melado,” which usually contains a considerable quantity of solid sugar, is sometimes employed with advantage in the manufacture of plain spirit. Treacle, the produce of the sugar-refineries in this country, is hardly ever used by distillers. It is too deficient in saccharine value, and two variable in composition to serve their purpose, when working on the large scale for the home-market. It is besides apt to communicate an unpleasant flavour to the spirit obtained from it, which the rectifier finds it difficult and costly to remove. But the illicit distiller, especially if he carries on bis operations in a large town, regards treacle as the material best suited to his purpose, on account of its cheapness, the facility of procuring it without exciting suspicion of his object, and the despatch with which it can be made into wort and all traces of his proceedings effaced.
Mashing.—This operation on the part of the distiller, where malt only is employed, is in all respects similar to the mashing process of the beer brewer. The malt need not be of so good a quality or so carefully prepared as malt designed for use in brewing, because in the latter case, the character of the malt must have a marked influence on the flavour and fineness of the beer produced from it, while in the case of distiller's wort it is the spirit only and not the fermented liquid containing it which is consumed as a beverage. The object aimed at in the manufacture of malt for distillers' purposes, especially for the use of those traders who work from a mixture of malt and raw corn, is the development of diastase rather than the complete saccharification of the starch in the grain ; for when the crushed malt is infused in water at a temperature favourable to the action of the diastase, that substance not only converts the remaining starch into sugar, but has the power of producing the same change in a great quantity of starch added from other sources, one part of diastase being capable of transforming 2000 parts of starch into dextrine and sugar. Diastase exerts its properties most energetically when the temperature of the mash is between 150° and 160° Fah.
In the enormous mash tuns which are used at some of the grain distilleries, the tranformation of starch into sugar is generally effected with facility and despatch, as it is much less difficult to keep up the proper heat, and thus promote the action of the diastase, when large quantities of materials and vessels of great magnitude are employed. The distiller has occasion to be even more careful than the beer-brewer, as to the regulation of his mashing temperatures, since the pale or low dried malt which is exclusively used by distillers is apt
Sugar or molassos spirit, as it is manufactured in this country, has little if any of the characteristic odour or flavour of, rum. This is explained by the fact that in the fermentation of the wort from which rum is prepared, the skimmings and other impurities of the crude molasses, together with pieces of the tops of the sugar-cane are purposely allowed to remain in the liquid, and that these give rise to a poculiar oil or ether which distils over with the spirit, and confers on it the aroma recognised as that of rum.
to “set” or form a tenacious, pasty mass with the goods if water at too high a heat be run into the mash-tun. It is a rule in these matters, that the higher the temperature at which the malt has been dried, the hotter may be the liquor made use of for mashing, while the less is the probability of the meal setting
It has already been stated that raw corn intended for mashing requires to be finely ground. Hence the use of mill-stones is necessary in order that the natural cohesion of the grain may be effectually overcome, and a powder of sufficient fineness produced, as otherwise the mash liquor would not have access to every part of the meal, and a portion of its available constituents would be turned to no accountMalt, on the other hand, from its greater friability, yields all its soluble matter to water, when it has merely been crushed or bruised between rollers. Distillers, however, frequently find it advantageous to avail themselves of a recent relaxation of the law, permitting them to grind malt with stones in the same manner as unmalted grain.
As to the nature and relative proportions of the different kinds of raw grain that are used by distillers, it will be sufficient to state, that almost any description of grain free from taint answers as a material for the production of spirits. The great object of a distiller is, of course, to obtain a supply of sugar or starchyielding substances at the lowest possible cost, but as certain substances which would furnish starch abundantly and economically have been found to give rise in the process of fermentation or distillation to oils and ethers of a very disagreeable character, and as these, despite every precaution and artifice, contaminate the accompanying spirit to an extent that frequently renders it unsaleable, the distiller is obliged to restrict himself, as a rule, to the use of a few well-tried and unobjectionable materials. Independently of the bad flavour of the spirit distilled from most of the substitutes for grain, great difficulty is experienced in conducting the operation of mashing, so as to obtain from them the greatest quantity of sweetwort which they are capable of yielding. Rice, for instance, however finely ground or however much its farina may be softened by preliminary treatment with hot water or steam, becomes very imperfectly saccharified under the action of the diastase of malt. In order to employ rice successfully as a source of alcohol, it is necessary to place the grain in contact with sulphuric acid and water at a very high temperature.* A small portion of the acid, when a proper heat is maintained, converts the starch of the rice, after a time, into syrup, and this when freed from the acid by the addition of lime, and fermented and distilled, affords alcohol in sufficient quantity to be highly remunerative, if only the quality of the product were unexceptionable. But no process that has hitherto been devised, has overcome the disagreeable flavour of the spirit thus obtained.
Similar objections apply to the manufacture of spirits from potatoes, beet-root, carrots, locust beans, and various other substances of the same class, all of which have been tried and abandoned as unprofitable.
In addition to the advantage which both malt and grain spirit possess in respect of quality, the cost of production is considerably lessened by the value of the “grains," that is, the residue after mashing. The working expenses of many distilleries are defrayed by the sale of this refuse together with the 'spentwash," to cattle feeders. An equal source of profit is not afforded by
* This process is at present protected by a priteut, so that it is not available to distillers generally.