Comprehensive look at alcohol distillation

The object of distillation is the preparation of alcohol or pure spirits, which is obtained from brandy, rum, arrack and whiskey, prepared from wine, sugar, rice and malt. It also includes compound spirits, or those which, in addition to alcohol, contain some volatile or pungent oil or essence, as gin, hollands, caraway and peppermint; the essential oils, as oil of cinnamon, oil of cloves, oil of peppermint, and otto of roses, and the simple distilled waters which retain the fragrant flavor of the particular herbs with which they have been distilled.

_To manage Distillation._

Previous to distilling, the process of brewing and fermentation are necessary. The distiller, however, need not take the precautions of the brewer or wine-maker in moderating his fermentations so as to secure the good flavor and keeping qualities of the product. His object is to get as thorough a fermentation, and therefore as much alcohol, as possible. Hence large quantities of yeast are used, which is not skimmed off, but worked into the wort. He also mixes a quantity of raw grain with his malt in the mash, the diastase of the malt sufficing to convert all the starch of the raw grain into sugar. The quantity of raw grain may be twenty times that of the malt. All the saccharine matter cannot be converted into alcohol, the large quantity of alcohol formed towards the last of the process checking the fermentation. About one-fifth of all the saccharine matter remains in the grains. These are fed to cattle.


In a distillery are required a variety of utensils, such as still, worm-tub, pump, a water-cask, a strong press, hair-cloths 3 or 4 iron-bound tubs capable of containing from a hogshead to a pipe of any liquor, 3 or 4 cans capable of holding from 2 to 6 galls. by measure, an iron-bound wooden funnel having a strong iron nosel or pipe, a pewter syphon about 6 feet long and 4 inches in circumference, flannel bags for refining the thick and suculent matter at the bottoms of the casks and other vessels.

_Operation of the Still._

When the still is charged let the fire under it be lighted, and whilst it burns up the joints should be carefully luted.

By laying the hand on the still and capital, as the fire gains strength, the process of the operation will be ascertained; for whenever the head or capital feels hot, it is a proof that the volatile particles have arisen, and are about to enter the worm. When the still head is about to become hot, prepare a damp, made of the ashes under the grate, mixed with as much water as will properly wet them. This mixture is to be thrown upon the fire, to moderate its action, at the instant when distillation has commenced. Continue the heat as long as the distilled liquid is spirituous to the taste. When the distilled liquor carries with it any particular flavor, it should be re-distilled with essential oils, in order to convert it into a compound spirit, as gin, peppermint, and other cordials.

When all the spirituous fluid is drawn off, the still should be emptied by a cock in the side. The head etc., should then be removed, and the several lutes taken clean off. The still may now be charged a second time, and luted. If the spirit or compound to be made is of a different nature or flavor from that procured by the last distillation, the still, capital and worm should be thoroughly cleaned by hot water, sand and a scrubbing brush, to remove the oily particles that adhere to their internal surfaces. The worm is best cleansed by passing hot water through it repeatedly, until the water flows out quite flavorless.

Great care should be taken that no grease, tallow, soap, or any other unctuous matter, fall into the tubs, pieces, rundlets, or cans. Above all things, lighted candles, torches, or papers should not be brought near any vessel containing spirits. The flue or chimney should be kept constantly clean.

_To Use a Portable Furnace._

In the laboratories of experimental chemists, portable furnaces are employed. Charcoal is the only fuel that can be used in them, except the occasional use of the finer kinds of stone coal that yield a bright flame, and burn to a white ash without forming clinkers. When the fire is regulated by the admission of only the necessary quantity of air through the charcoal, and the whole heat of the fuel is directed upon the subject exposed to it, the expense is not so great as might be supposed, for no other fuel gives out so much heat. One lb. of charcoal will boil away 13 lbs. of water, whereas the same weight of Newcastle coal will boil away only 8 or 9 lbs. A pound of coke will only boil away 4 lbs. of water, and a pound of peat seldom more than 5 lbs., or, by a skilful mode of using it, at the utmost 10 lbs.

_To Build Fixed Furnaces._

Fire bricks are generally used, as they may be cut as easily as chalk, and yet bear a violent heat without alteration; they must be set in clay of the same kind. The parts distant from the fire may be of common bricks set in mortar, but this mortar must be carefully removed before the other part is begun, as an accidental admixture of it with the clay would cause the latter to run into glass, and thus spoil the furnace. These furnaces are generally built as thin as possible, that they may take up the less room, and to save fuel in heating them, as they have seldom fire constantly in them; in this case they should be surrounded with iron braces, to prevent the alternate contraction and expansion destroying them as soon as they otherwise would.

_To make a Portable Sand-pot._

For a portable one the ash pit may be an iron cylinder 17 inches in diameter and 8 deep, closed at bottom. In the front is cut a hole 3 inches high and 4 wide, with sliders to shut close. Three pins are riveted on the inside about an inch below the upper edge; these are to support the fireplace. The bottom of this ash pit is lined with clay, beat up with charcoal dust and formed into a kind of saucer. The fireplace is a small cylinder of nearly the same width, so as to fit easily into the top of the ash-pit, and rest on the three pins; its height is 15 inches, and it has a flat border at each end leaving a circular opening of 10 inches in diameter. Around the lower border are riveted 3 screws, to which are fixed by nuts a grate. In the upper border, towards the circumference, and at equal distances from each other, are made 4 circular holes an inch over. The inside of the fireplace is lined with clay and charcoal, whose surface is adjusted to a core, made by drawing on a board an ellipsis, having its foci 15 inches asunder, and its semiordinates at the foci 5 inches, sawing off the board at each focus, and also down the greatest diameter, so that the internal cavity may represent an ellipsoid of those dissensions, cut off at the foci.. A fire hole about 6 inches wide and 4 1/2 high, with the lower limit about 3 inches above the grate, is left in the front to be closed with a lined stopper, both the firehole and stopper having a border to retain the lining. When the lining is dry, 4 openings are cut sloping through it, corresponding to the openings in the upper border, to serve as vents for the burnt air, and to regulate the fire by sliding pieces of tile more or less over them. In the central opening at the top of the fire-place is hung a cast-iron pot, either hemispherical, or, which is most usual, cylindrical, about 6 inches deep at the edge, with a rounded bottom, so that the axis is about an inch deeper. The common pots have only a reflected border, by which they hang, but the best kind have also an upright edge that rives an inch higher, to which a stone-ware head is fitted, and thus the pot serves for many distillations that require a strong fire. It is usual to cut a notch on one side of the top of the fireplace, sloping upwards to the edge of the pot about 3 inches wide and 2 deep, to admit a low retort to be sunk deeper into the pot, by allowing a passage to its neck.

_To make a Sand-heat Furnace._

A furnace of this kind may be stationary, and built of bricks that will stand the fire, and in this ease the ash-pit is built about 12 inches high, and has an ash-door opening into it about 6 inches square; a grate is then laid, and a fire-door 6 inches by 8 opens immediately into the fireplace, even with the grate. The fire-place is made cylindrical, 2 inches wider than the sand pot, and about 8 inches deeper, the grate being a square whose side is about two-thirds the internal diameter of the Band-pot. This pot hangs by its border in an iron ring placed at the top of the furnace; we have not yet adopted Teichmeyer's method of sloping the pot. As stone coal is generally used in fixing furnaces, instead of the 4 register holes used as vents in the portable furnaces, only one opening, about as wide as the grate and 3 inches high, either in the back or on one side, is made to vent the burned air into the chimney. This, however, has the inconvenience of heating the pot unequally, next the vent becoming much the hottest, in spite of the endeavor to equalize the heat by bringing the fire from under the centre of the pot as forward as possible, by raising the wall opposite to the vent perpendicularly, and enlarging it only on the other three sides; sometimes with the same view several small vents are made round the pot, leading into the chimney. A notch for the neck of the retort is generally made on one side. As much heat passes through the vent, it is usual to cause the heated air to pass under a large cast-iron plate, placed on a border of bricks surrounding a platform of the same materials, and leaving a cavity of about 2 1/2 inches deep at the farther end of which another opening leads into the chimney. On this iron plate sand is laid to form a sand heat, and thus several operations are carried on at the same time. If that in the sand-pot is finished, and it is desired to keep on those in the sand-heat without interruption, the vessel may be drawn out of the sand, some warm sand thrown on that remaining in the pot, and a fresh vessel with materials introduced. But if this new operation should require the heat to be more gradually exhibited, a pot of thin plate-iron, filled with cold sand, containing the vessel, may be partly slid into the heated sand-pot, and, being supported by pieces of brick placed under the edge or otherwise, kept there until it be necessary to increase the heat when it may be slid down lower until at length it is permitted to reach the bottom of the sand-pot.

_To make a Pot Still._

Portable pot stills should have an ash-pit and fireplace exactly similar in dimensions to those used with the sand-pot, or the same furnace may be used with a hot still, if economy and not convenience is the principal object. The copper or tin-plate cucurbite will, of course, be 10 inches wide and about 12 deep, and hang 7 inches within the fireplace. The mouth should be wide, that the water-bath to be occasionally hung within it so as to reach within 3 inches of the bottom, may be the larger. Between this wide neck and the circumference there should be a short pipe, through which the liquor left after distillation may be drawn off by a vane without unluting the vessels; fresh liquor added; or, in distilling with the water-bath, the steam may escape. This pipe has a ring round it, that the cork with which it is stopped may be firmly tied down, and like the other joinings be luted, for which purpose slips of paper smeared with flour and water, or common paste, are usually esteemed sufficient; but the best material is bladders rotted in water until they smell extremely offensive and adhere to the fingers when touched, and then worked between the hands into rolls, which are to be applied to the joinings. These small stills have usually a Moor's head that fits both the cucurbite and the waterbath, their necks being of equal diameter, and is furnished with a groove round the lower part on the inside to direct the condensed vapor to the nose of the alembic, and this head is surrounded by a refrigerator containing cold water, which is not so cumbersome as and less expensive than a worm and tub. But the most advantageous way of cooling the vapors is to use a Moor's head without a surrounding refrigerator, or only a plain bent tube, which should be at least 18 inches long, that the small globules of the boiling liquor which are thrown up near a foot high should not pass over and render the distilled liquor unfit for keeping. To this is to be adapted a pewter pipe about 8 feet long, if spirits of wine is to be distilled, or shorter for watery liquors, and in both cases 3/4 of an inch in diameter on the inside, inclosed in a tinned plate tube with a funnel. With an adopter of this kind, and the consumption of 1 1/2 pints of water in a minute, or about 9 galls. in an hour, spirits of wine may be distilled at the rate of a gallon by the hour from one of these portable stills. Another convenience of these straight pipes is, that they may be cleansed in the same manner as a fowling piece.

_To make a Large Still._

If this furnace is fixed, and made of bricks, it may be constructed with a sand heat like that annexed to the sandpot; but this is seldom practised, although it would be advantageous for digestions and evaporations with a gentle heat, because the fire is generally kept up at an even height. It the cucurbite is not wanted for distilling, it may be used as a boiler to keep water ready heated for use, and to be drawn off when wanted by a syphon or crane. But these fixed stills are usually furnished with a pipe and cock on a level with the bottom by which they can be emptied and have almost always a worm and tub to cool the vapors. The head is usually of that kind which is galled a swan's neck.

_Astier's Improved Still._

It has been proved that as soon as a common still is in operation, the steam from the capital in the first turn of the worm is at a temperature of about 212 Fahr. Here water only condenses and the alcohol in vapor passes into the second turn where it condenses by the lowered temperature. If the condensed liquid is drawn off from the upper turn, it is mere phlegm, or water, while that from the second turn is alcohol or spirit. The mode of doing this is very simple, and can be applied to any old still; so that every advantage resulting from the most complicated and expensive stills can be obtained; that is to say, plain brandy, Dutch-proof, and even thirty-five and thirty-sixth; proof. The alterations are effected as follows: Each turn of the worm is to be furnished with a very slender lateral pipe, ending in a faucet and tap. A crescent-shaped valve, placed just before the opening of the pipe into the worm, obliges the condensed liquid to trickle into the pipe, and a slight elbow above and below the pipe prevents any of the steam from running in the same direction. Each of these pipes follows the main worm in all its convolutions, comes out of the condenser at the same opening, and is led thence to its own receiver. The pipe of the first turn has also a second branch with a faucet, which lets out the phlegm (which is worthless) as fast as it is condensed. A prover indicates the moment when the feints should be separated, as simple brandy or proof-spirit is wanted. These feints are either detained in the boiler, or set aside for rectification, in all cases necessary, for the last spirit that comes over, without which it is worthless.

Besides producing more spirit, and saving threefourths out of the feints, the worm prepared as above shortens the term of distillation by one-half, and consequently reduces the expense of fuel. In addition to this, and what is of more consequence, a sour wine may be distilled as well as any other, and without the least taint being perceptible in the brandy. The spirit is, of course less in quantity, but whatever is obtained is good and all the acid separates and flows out by the first pipe, which gives an opportunity of profiting by the acetous portion.

_Column or Continuous Distillation._

A copper boiler is set in masonry, with a fire beneath: the mouth of the boiler is fitted with a tall copper cylinder, standing perpendicularly over the boiler and fitting closely. About half way up the height of this cylinder, and in its axis, a slender tube enters it and discharges a continual but small stream of the wine or wash to be distilled. The wine is prevented from falling down directly into the boiler beneath by means of a number of diaphragms, through which the wine percolates in streams like rain, whereby it presents a large extent of surface to the vapor which passes it in a different direction. In some cases the ascending vapors have to force their way at each diaphragm through a thin stratum of liquid and they thus undergo a certain amount of pressure. The wine, when it enters the cylinder, is almost boiling, and, while it falls in small showers through the pierced shelves, a copious issue of watery vapor ascends from the boiling copper below. The watery vapor, at the temperature of boiling, comes in contact with the wine almost boiling; the latter, therefore, receives heat from the former, and by so doing there is a change of state; the watery vapor, losing heat, falls back as water, and the wine, acquiring heat, boils, and its alcohol, in a state of vapor, rises higher up in the cylinder, where, meeting with wine, it is absorbed, and a wine richer in alcohol is produced. This more alcoholic wine readily parts with its alcohol, in the form of vapor, by the action of heat continually carried up the cylinder. This vapor of alcohol, ascending higher, meets with more wine, is absorbed, and again set free in larger quantity. At length the portions of wine high up in the cylinder become highly charged with alcohol, and the alcoholic vapors, meeting with no more wine, pass on to a worm, where they are condensed into very strong spirit. The worm-tub is filled with wine, which in cooling the worm becomes heated itself, and this heated wine flows through the slender tube into the cylinder, where it is distilled as already explained. As this worm is never perfectly cold, the alcoholic vapor which escapes condensation is passed through a second worm also surrounded by wine, which condenses it completely.

Should the watery vapor which ascends from the boiler into the cylinder, and becoming condensed, falls back into the boiler, carry any alcohol with it, the latter is again volatilized; so that the boiler contains nothing but water, derived from the wine; for, although the boiler had been filled with wine, it soon becomes water by parting with its alcohol. As fast as the boiler fills with water, it is emptied by a cock placed in the bottom. Two boilers are more efficient than one, and when arranged so that a tube proceeding from the head of one plunges to the bottom of the other, they act like two of the eggs in Adams's still.

The discharge of wine from the great reservoir is regulated by a ball-cock, and there is a constant supply of cold wine, first, to the two worms, for the purpose of cooling them (by which method of heating the wine fuel is economized); secondly, to the distillatory column. Having parted with its alcohol, the watery portion falls into the boilers whence it is let off entirely deprived of alcohol. The flow of wine being thus perpetual, no time is lost by an interval of discharging and charging. It must also be noticed, that when the alcoholic vapors enter the first worm they are condensed; but as the weakest or most watery alcohol condenses in the first rounds of the worm, it is so contrived that this watery portion shall run back by small tubes into the cylinder, where it is redistilled. The worm at all its rounds is provided with cocks and tubes, by which the portions condensed in any part may be let back to be redistilled; or they may be all shut, or some may be left open, so as to return the whole or any part into the cylinder. In this way, by means of these cocks, alcohol of any required degree of condensation, within certain limits, can be obtained.

_To Dulcify Spirits._

In dulcifying, or sweetening the spirits, weigh the sugar, and dissolve it in one or more cans of the water with which the compound is to be made up, bruise the sugar, and stir it well till all is dissolved. Then empty it into the cask containing the spirits, mixing all together by drawing off several cans by the cock, and emptying them into the casks by the bung-holes. Now rummage all well together till they are perfectly compounded.

Spirits or compounds that are strong require no assistance in setting and becoming clear; but those that are weak must be refined by the addition of some other substance. To every hogshead of Geneva, or other spirituous compound put 6 oz. of powdered alum, previously dissolved in 3 or 4 galls. of the compound: stir all well together. In the course of 24 hours the whole will be rendered completely clear.

It is a good practice to leave the bung-holes of casks (containing spirits or compounds newly made) open for several days. This improves their flavor, and renders them clear sooner than they would otherwise be.

Table-salt thrown into the still, in the proportion of 6 oz. to 10 galls. of any liquid to be distilled, will greatly improve the flavor, taste, and strength of the spirit. The viscid matter will be fixed by the salt, whilst the volatile matter ascends in a state of great purity.

The flavor of malt spirits is highly improved by putting 3 1/2 oz. of finely-powdered charcoal, and 4 1/2 oz. of ground rice into a quart of spirits, and letting it stand during 15 days, frequently stirring it; then let the liquor be strained, and it will be found of nearly the same flavor as brandy.

_To make Jamaica Rum._

This is obtained from the refuse of the raw sugar manufactories, by taking equal quantities of the skimmings of the sugar pans, of lees or returns as they are commonly called, and of water and to 100 galls. of this wash are added 10 galls of molasses. This affords from 10 to 17 galls. of proof rum, and twice as much low wines; it is sometimes rectified to a strength approaching to spirit of wine, and is then called double distilled rum.

_To Obtain Rum from Molasses._

Mix 2 or 3 galls. of water with 1 gall. of molasses, and to every 200 galls. of this mixture add a gallon of yeast. Once or twice a day the head as it rises is stirred in, and in 3 or 4 days 2 galls. more of water is added to each gallon of molasses originally used, and the same quantity of yeast as at first. Four, 5 or 6 days after this, a portion of yeast is added as before, and about 1 oz. of jalaproot powdered (or in winter 1 1/2 oz.), on which the fermentation proceeds with great violence, and in 3 or 4 days the wash is fit for the still; 100 galls of this wash is computed to yield 22 galls. of spirit from 1 to 10 overproof. If the molasses spirit, brought to the common proof strength, is found not to have sufficient vinosity, it will be proper to add some sweet spirits of nitre; and if the spirit has been properly distilled by a gentle heat, it may, by this addition only, be made to pass with ordinary judges as French brandy. Great quantities of this spirit are used in adulterating foreign brandy, rum, and arrack. Much of it is also used alone in making cherry brandy and other cordials by infusion; in all which many prefer it to foreign brandies. Molasses, like all other spirits, is entirely colorless when first extracted; but distillers give it, as nearly as possible, the color of foreign spirits.

_To Prepare Gin as in Holland._

The grist is composed of 10 qrs. of malt, ground considerably finer than malt distillers; barley grist, and 3 qrs. of rye-meal, or, more frequently, of 10 qrs. of rye and 3 qrs. of malt-meal. The 10 qrs. are first mashed with the least quantity of cold water it is possible to blend it with, and when uniformly incorporated, as much boiling water is added as forms it into a thin batter; it is then put into 1, 2, or more casks, or gyle-tuns, with a much less quantity of yeast than is usually employed by our distillers. Generally, on the third day, the Dutch distillers add the malt or ryemeal, prepared in a similar manner, but not before it comes to the temperature of the fermenting wash; at the same time adding as much yeast as at first.

The principal secret is the management of the mashing part of the business, in first thoroughly mixing the malt with the cold water, and in subsequently adding the due proportion of boiling water, that it may still remain sufficiently diluted after the addition of the fine meal; also in well rousing all together in the back, that the wash may be diluted enough for distilling without endangering its burning to the bottom.

_Rectification into Holland Gin._

To every 20 galls. of spirit of the second extraction about the strength of proof, take of juniper-berries, 3 lbs.; oil of juniper, 2 oz.; and distill with a slow fire until the feints begin to rise, then change the receiving can; this produces the best Rotterdam gin.

An inferior kind is made with a still less proportion of berries, sweet fennel seed, and Strasburg turpentine, with a drop of oil of juniper, and a better sort, but inferior to the Rotterdam, is made at Weesoppe. The distiller's wash at Schiedam and Rotterdam is lighter than at Weesoppe, Strasburg turpentine is of a yellowish-brown color, a very fragrant agreeable smell, yet the least acrid of the turpentine. The juniper berries are so cheap in Holland, that they must have other reasons than mere cheapness for being so much more sparing of their consumption than our distillers.

_To make Malt Spirit._

Mix 60 quarters of barley grist, ground low, and 20 quarters of coarse ground pale malt, with 250 barrels of water, at about 170. Take out 30 barrels of the wort, and add to this 10 stone of fresh porter yeast, and when the remaining wort is cooled down to 55, add 10 quarters more malt, previously mixed with 30 barrels of warm water; stir the whole well together, and put it to ferment, along with the reserved yeasted wort; this wash will be found to weigh, by the saccharometer, from 28 to 32 lbs. per barrel, more than water. In the course of 12 or 14 days, the yeast head will fall quite flat, and the wash will have a vinous smell and taste, and not weigh more than from 2 to 4 lbs. per barrel more than water. Some now put 20 lbs. of common salt, and 30 lbs. of flour, and in 3 or 4 days put it ins`> the still, previously stirring it well together. Every 6 galls. of this wash will produce 1 gall. of spirit, at from 1 to 10 over-proof: or 18 galls. of spirit from each quarter of grain.

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