Popular Science Monthly/Volume 29/May 1886/How Alcoholic Liquors are Made
WHATEVER may be our individual views or prejudices in relation to the use and abuse of alcoholic liquors, the process of their manufacture is a very interesting chemical operation. Proof-spirit is defined by the United States internal revenue laws to be that mixture of alcohol and water which contains one half of its volume of absolute alcohol and 53·71 parts of. water. When the alcohol and water are mixed together — while combining — contraction in volume takes place to the extent of 3·71 parts, resulting in 100 parts of proof-spirit. The law declares that the duties on all spirits shall be levied according to their equivalent in proof-spirits. The hydrometers adopted by the Government for the purpose of testing the degree of strength are graded and marked (0°) for water, (100·) for proof-spirit, and (200°) for absolute alcohol, at a standard temperature of 60° Fahr.
Alcoholic liquors can be made from any substance that contains saccharine matter already formed by Nature, or from any substance that contains the constituent elements that can be converted by some artificial process into the saccharine principle. In the United States they are generally produced from corn, rye, wheat, barley, rice, molasses, apples, grapes, and peaches; sometimes from potatoes and beets. Vinous fermentation converts sugar, glucose, or saccharine matter into alcohol and carbonic-acid gas; the latter passing off into the atmosphere.
In order to bring about vinous or alcoholic fermentation five agents are indispensable, viz., saccharine matter, water, heat, a ferment, and atmospheric air. Sugar or saccharine matter in its various forms is the only element from which alcohol can be produced; the others are mere auxiliaries to the decomposition.
By establishing the quantity in volumes of the elements of sugar and alcohol, as indicated by the following tabulated statements, and by comparing the constituent elements of the two articles, so dissimilar in appearance, the fact of their slight difference would be incredible were it not established by science:
|br|sc}|composition of sugar in volumes.||composition of alcohol in volumes.|
|Vapor of carbon||3||Vapor of carbon||2|
Take one volume of vapor of carbon and one of oxygen from sugar, which is accomplished by vinous fermentation and distillation, and you have alcohol.
In order to obtain the best results, the process of scalding the various kinds of grain used and making the yeast requires very skillful management; so much so that the largest distillers employ a professional and practical chemist to look after the scientific part of the business. The quantity and power of the yeast, in proportion to the quantity of saccharine matter in the mash, must be properly balanced, or in one case the fermentation will be too rapid, developing excessive heat, and consequently a loss of alcoholic vapor passing off with the carbonic-acid gas, also inducing acetic fermentation, which, under certain conditions, is a destroyer of alcohol; or, in the other case, if the yeast is too weak, so that it will not convert all the saccharine matter into alcohol, there will be a waste of material, and consequently a pecuniary loss to the manufacturer.
Can pure unadulterated alcoholic liquors be now obtained? This is a question frequently asked with a doubtful accent. I answer yes, as pure as were ever made, which assertion I will substantiate by giving a description of their manufacture. And as whisky is one of the most common liquors, it may be taken as an example. Malt is an almost indispensable article in connection with whisky-distilling, and is usually made of rye or barley. The grain is soaked in water until it begins to swell; it is then placed in a pile on the malting-floor, where it remains until heat is generated and saccharine fermentation takes place, causing the grain to germinate or sprout, and developing the saccharine matter and a peculiar ferment called diastase, which is the main object in the process of malting. When the process of germination has arrived at the point desired, the grain is spread over the floor to dry, for the purpose of suspending further fermentation; when dry, the grain is very sweet and brittle, easily ground, and is known to commerce as rye and barley malt.
The best distillers are very particular about the quality of grain they use, buying only the best in market. The proportions of each kind of grain used vary according to the particular brand of whisky desired. The usual proportions of grain are, two thirds corn and one third rye and malt. The corn is ground into a fine granulated meal, the rye to a medium fineness, and the malt is coarsely ground. The meal is all weighed, scalded, and mashed under the supervision of the United States internal revenue storekeeper. The corn-meal, being more difficult to scald than rye and malt, is first put into a mash-tub containing a proper quantity of hot water, and while the mash is being vigorously stirred with a revolving rake driven by steam or waterpower, the temperature is raised to about 170º Fahr. This operation scalds the corn-meal and develops the starch; after remaining at this temperature for the proper length of time, cold water is added to reduce the temperature to about 150º Fahr., the rye and malt are then added, and the whole mass is continually stirred until the scalding is complete, and the starch is developed and converted into dextrine, and then into saccharine matter by the potency of the diastase contained in the malt. It is then cooled down as quickly as possible, in order to avoid viscous fermentation, by the addition of cold water and ice, to about 80º Fahr., and drawn off into a fermenting vat, and the yeast which has been previously prepared is added.
The fermenting period varies from forty-eight to seventy-two hours, according to the kind of yeast used. By testing the density and temperature of the mash at the time of setting, and on the completion of fermentation, with the aid of a saccharometer and thermometer, a close approximation can be obtained of the quantity of proof spirit contained in the beer—by which name the mash is called after fermentation; the greater the attenuation of the beer, as shown by the saccharometer, the greater the quantity of spirit.
Fermentation being completed, where the ordinary copper stills are used, the beer is run into one still and is boiled; the alcohol in the beer, being more volatile than water, rises, combined with more or less water, and passes through a copper coil or worm submerged in a cistern of water into which a continuous stream of cold water is running; at the top of this cistern is an overflow-pipe conveying the heated water off as it rises. This operation condenses the vapor in the worm, and the spirit flows out colorless; as all spirits, whether made from grain, fruit, or vegetables, flowing from the still-worm, have the appearance of water.
The product of this first distillation is called low-wine, from the fact that it is not of sufficient strength and purity to put upon the market. The boiling is continued until all the alcohol in the beer is evaporated and condensed; then the refuse is drawn off from the still and fed to cattle and hogs. The low-wine is then run into still No. 2, called the doubler, and boiled again. The product from the doubler will be whisky varying from 100º to 150º in strength.
When the three-chambered wooden still or column is used, and the beer is boiled by steam, spirits are produced of marketable strength at each run of the still.
Under the internal revenue laws the distillers of grain and molasses can have no access to the spirits during the process of their manufacture, as the spirits are conveyed from the still in continuously closed pipes to large cisterns in a room with only one entrance, upon which is a Government lock, of the key of which the United States gauger is the custodian, until the spirits have been drawn off into barrels, and he has gauged the quantity and tested their degree of strength by the aid of a hydrometer and thermometer, placed a warehouse stamp on each package, and marked on each the capacity, quantity, and degree of strength of the contents.
The gauger is, fortunately, not required to taste of the spirits to test their quality, as quality is not taken into consideration in levying the tax. After the gauger has completed his duties, the United States storekeeper takes charge of the spirits and sees that all of the packages are safely deposited in the distillery bonded warehouse, where they remain under a Government lock the key of which is in the care of the storekeeper until—the tax is paid.
The limit of time that spirits can remain in bond, by the present revenue law, is three years. Congress was petitioned at the last two sessions, by parties interested in distilling, for an extension of the bonded period, but the petition was, I think, unwisely denied.
It would be a blessing to the whole country if Congress would pass a law embodying the substance of the three following items: 1. Granting unlimited time for spirits to remain in bond, in order to give all the time for improving the spirits desired before payment of the tax. 2. Prohibiting the withdrawal of alcoholic liquors from bond until they have been in the warehouse at least twelve months; for the reason that new spirits, although they may be pure, are not fit for internal use, and should not be placed upon the market for sale until their constituent elements are thoroughly combined by age. 3. Prohibiting (if it can be done constitutionally) the mixing or compounding different kinds of alcoholic liquors, particularly those made from grain with those made from fruit, or the adulteration of the same by the addition of any deleterious or injurious substances. Heavy penalties to follow every violation and conviction.
Various contrivances have been adopted, both in this and foreign countries, for the purpose of producing a kind of artificial age, and various compounds have been used to accomplish the desired result, and to a certain extent have been successful in deceiving the novice or uninitiated; but, on the whole, you might as well try to put a mature brain, developed in all its manly proportions, upon the shoulders of a youth, as to try to make new spirits old, minus the element of time, and the necessary accompanying environments.
A company in Boston, Massachusetts, claim to purchase the oldest liquors they can find in distillery bonded warehouses (three years old), and to purify and increase their mellowness by forcing warm air through them, thereby oxidizing the fusel-oil (or heavier alcohols), and expelling into the open air the light, poisonous ethers, leaving the liquors free from the aldehydes which stupefy and destroy the brain tissues. The air is first passed through a chemical solution (Professor Tyndall's well-known method), which deodorizes as well as destroys all germs of animal or vegetable origin; and after being thus treated, analysis shows it to be pure atmospheric air, 79 parts nitrogen, and 21 parts oxygen. This purified air is then heated to a certain temperature, and, with the aid of a pump, forced through pipes with almost infinitesimal perforations, so as to bring the greatest amount of surface of air in contact with the greatest amount of surface of liquor in the shortest space of time, warming the liquors and producing a violent agitation, which process, undoubtedly, accelerates the union and assimilation of the constituent elements, and, they also claim, eliminates the poisonous gases. The liquors are then filtered by the best known methods to free them from any remaining débris.
But to return to the distillery: you will see that the processes which the grain has gone through of mashing, fermenting, and the extraction of the spirits from the beer by distillation, and the placing of the completed product in the distillery bonded warehouse, are all done under the supervision of a Government officer, and thus far the distiller has had no opportunity, even if he had any desire, to adulterate the liquor. Any distiller who wishes to establish a reputation for manufacturing a fine article, is as much interested in keeping his liquor pure as any person is who wishes to purchase and properly use a pure article.
After the internal revenue tax has been paid, and the tax-paid stamps properly placed upon the packages, the spirits are withdrawn from bond; each package having two stamps upon it—a warehouse and a tax-paid stamp—and when put upon the market in this condition they are known as two-stamp goods; but the best distillers, instead of selling their goods directly from the bonded warehouse—if they have not been filtered and refined during the process of their manufacture—transfer them to the rectifying-house for rectification; the object of which is to remove any pernicious substances or impurities, such as the grosser properties of the essential oils, or fusel, and acetic acid, and to improve the quality and flavor of the spirits. It is the essential oils extracted from the various materials used that impart the peculiar distinguishing characteristics to each kind of liquor. The alcoholic property is virtually the same in all spirituous liquors.
The process of rectification is generally done by redistilling, and filtering through alternate layers of woolen blankets, sand, and granulated bone or maple charcoal—other complicated mechanical arrangements are sometimes used, called rectifiers, but they are not common—after which process, a little burned sugar is added to give them a kind of straw-color, simply, I presume, to distinguish them from water, and which gives the appearance of age without improving or injuring their quality. After rectification, the spirits are gauged by the United States gauger, and a rectifier's stamp is placed upon each package, and the whisky is then ready for the market, pure and unadulterated, and, known as one-stamp goods. Remember that I am now stating how good whisky is made; all whisky is not made with the same degree of care. Some people are under the impression that if they buy two stamp goods they are certainly getting a pure article, but that is not always the case, unless the whisky has been properly rectified during the process of manufacture.
There is a vast difference between rectification proper and mixing or compounding. Rectification, in its proper sense, is purifying and refining. Compounding is diabolizing. Moral: Purchase from first hands, if possible.
By this, I do not mean to insinuate that all dealers in liquor are unscrupulous; for, paradoxical as it may appear to some minds, there are many very generous, noble-hearted, upright men engaged in the liquor-traffic; but the demand for cheap liquor is so great that some men can not resist the temptation to mix or compound, in order to supply this demand, and some of them feel that they are compelled to do it against their will in order to hold their customers; and this practice will continue until the strong arm of a righteous law is placed upon it—a law that every honest distiller and liquor-dealer will cordially approve.
Therefore, if you want a pure article, purchase from a distiller or first-class, reliable dealer; and, by the term first class, I do not mean the man who has the largest and most attractive place of business, and the most capital invested, but the man who is known for his integrity and truthfulness of character. Insist that the spirits must be at least twelve months old, and also be willing to pay a fair price for them. There is no more exception to the rule in the liquor business than in any other, that, if you want something of value, you muse expect to pay value for it.
At some distilleries, the spirits pass through a process of filtering between the worm and cistern-room, which extracts the impure foreign matter that is unavoidably forced up from the still with the vapor of spirits. When this purifying process is skillfully and carefully done, there is no absolute necessity for the further manipulation or rectification of the spirits, and the only element then required to make the spirits fit for medicinal purposes is time, and the longer the time the better. If kept in wooden packages the spirits will improve and acquire a slight color by age. Coloring-matter is not allowed by the Government to be put in the spirits when this filtering process is done at the distillery.
Alcoholic liquors should not be offered for sale until they have been filtered or properly rectified, either during the process of manufacture, or after they have been withdrawn from the distillery bonded warehouse. The best distillers never let their goods go on the market until they have themselves put the whisky through a process of rectification, or refining; and woe be to the man who dares to change its character in the original package bearing their brand, if they find sufficient evidence against him!
Rye-whisky is made from rye and malt, without corn, but experts say that it requires much longer time to mature, and become ripe and smooth, than does Bourbon whisky, which is made from corn, rye, and malt. Gin is made from the same materials and in the same manner as whisky, with one addition: juniper-berries are boiled in the last distillation, imparting their peculiar flavor.
There are two objections to straight (unmixed) American gin: First, it is usually sold when new, because the dealer can buy it cheaper and make a larger margin upon it than he can on the old article. Second, straight American gin is not filtered and relieved of foreign and impure matters, but is sold with them in, obnoxious as they are, depending upon the juniper flavor to conceal their presence.
Rum is made from molasses, diluted with water, and a ferment added; after fermentation it is distilled in the same manner as whisky and gin.
Brandy is made from apples, grapes, peaches, and other fruits, generally from the expressed juice, but occasionally from the pomace or crushed fruit after fermentation. Fruits possess by nature an azotized albuminous substance which produces spontaneous vinous fermentation, so that artificial yeasts or ferments are unnecessary. About fifty per cent more brandy can be made from ripe than from green fruit, and late fruit will produce much more brandy than early fruit. Brandy-distillers ought to devote more attention to filtration than they are in the habit of doing; it is a moral obligation which they owe to society.
Some people are so credulous that they believe all imported liquors are pure and perfectly straight. By paying a very high price, pure imported liquors can be obtained, but the superiority of the best article consists mainly in great age. Some imported liquors are mixed, compounded, and artificially flavored before shipment to this country, and are again mixed with so-called pure spirit after their arrival here. Trois-six French spirit, when originally produced, was the pure spirit of grape-wine; now it is mainly manufactured from potatoes and the cereals, and forms the basis of many of the liquors imported into this country under the brand of French brandies and wines, and sold to a credulous public as the product of the pure juice of the grape.
The duty on imported liquors is two dollars per proof-gallon, and on imported wines fifty cents per wine-gallon, while the United States internal revenue tax is only ninety cents per proof-gallon on domestic spirits, and none on domestic wines. People can judge for themselves whether the imported article is worth the difference in price.
Chemists, in their analysis of anhydrous, absolute, or pure alcohol (200), do not exactly agree in their results. However, there is only a slight variation from the following statement in the proportions of the three constituent elements:
Alcohol showing the foregoing analysis acts as a caustic on the living tissues of the body, and by injection into the veins it causes sudden death by coagulating the blood. By introduction into the stomach it generally causes death.
Commercial alcohol is principally made from Indian corn, and generally indicates twelve degrees less in strength, being 188°, than the preceding analysis. This commercial alcohol is reduced to any degree desired by the addition of water, and known to the trade as French, pure, cologne, or neutral spirits, while in fact it is nothing but dilute alcohol.
This spirit forms the bulk of nearly all the low-priced alcoholic liquors, whether called rum, gin, whisky, domestic or foreign brandies, that are placed upon the market, and this neutral corn-spirit enters largely into many of the better brands. Some wholesale liquor- dealers and compounders state that liquors made from pure cologne or neutral spirits are the purest liquors that can be found. That may be true; also, sulphuric acid and aqua-fortis may and presumably are pure, but they are, nevertheless, dangerous and deadly poisons.
This neutral spirit has been robbed of all its native richness and reduced to a skeleton of extreme poverty by eliminating its natural oils and leaving it with a harsh, cutting, penetrating nature, and when taken internally it produces the worst effects upon the tissues. The natural oils in the materials from which alcoholic liquors are produced are the oils that have the greatest natural affinity for that particular kind of liquor, and if permitted to remain where they belong, when taken into the stomach in a refined condition, properly combined and assimilated, are bland and sedative in their effects, and any spirit that has been deprived of them is not fit to enter the human stomach.