We have hitherto considered the liquor as containing only principles upon which the air has no action, and from which it can only extract some watery vapors; and, in fact, all those principles contained in the liquor are fixed. The action of the fire may concentrate, but not volatilize them.
The liquor is now changed by the fermentation; it contains no longer the same principles, but has acquired those which it had not, which are volatile, and evaporate easily. They must therefore be managed carefully, in order not to lose the fruits of an already tedious labor.
The spirit already created in the fermented liquor, must be collected by the distillation; but in transporting it to the still, the action of the external air must be carefully avoided, as it would cause the evaporation of some of the spirit. A pump to empty the hogsheads, and covered pipes to conduct the liquor into the still, is what has been found to answer that purpose. A good distilling apparatus is undoubtedly the most important part of a distillery. It must unite solidity, perfection in its joints, economy of fuel, rapidity of distillation, to the faculty of concentrating the spirit. Such are the ends I have proposed to myself in the following apparatus.
The usual shape of stills is defective; they are too deep, and do not present enough of surface for their contents. They require a violent fire to bring them to ebullition; the liquor at bottom burns before it is warm at the top.
My still is made upon different principles, and composed of two pieces, viz. the kettle, and its lid. The kettle, forming a long square, is like the kettle of infusion, already described, and only differs from it in being one foot deeper. The lid is in shape like an ancient bed tester; that is to say, its four corners rise into a sharp angle, and come to support a circle 16 inches diameter, bearing a vertical collar of about two inches. This collar comes to the middle of the kettle, and is elevated about 4 feet from the bottom. The lid is fastened to the kettle. The collar receives a pewter cap, to which is joined a pipe of the same metal, the diameter of which decreases progressively to a little less than 3 inches: this pipe, the direction of which is almost horizontal, is 5 feet long.
My still, thus constructed, is established upon a furnace like that of the infusion room. I observe that the side walls are only raised to the half of the height of the kettle. A vertical pipe is placed on the side opposite to the pewter one, and serves to fill up the still: it is almost at the height of the fastening of the lid, but a little above. On the same side, on a level with the bottom, is a pipe of discharge, pa.s.sing across the furnace: this pipe must project enough to help to receive or to direct the fluid residue of the distillation; its diameter must be such as to operate a prompt discharge of the still.
OF THE URNS.
These are copper vessels, thus called from their resembling those funeral vases of the ancients. Mine have a bottom of about 18 inches diameter; they are two feet high, have a bulge of 6 inches near the top, and then draw in to form an overture of about 8 inches.
On one side, towards the top, there is a copper pipe 2 inches diameter, projecting externally 2 or 3 inches, and bent in an elbow: it enters the internal part of the urn, and descends towards the bottom, without touching it; there it is only a slight curve, and remains open.
The external part of that pipe is fitted to receive the pewter pipe of the still; they are made so as to enter into one another, and must fit exactly. The round opening at the top of the urn receives a cap with a pewter pipe, made like that of the still. It is likewise five feet long, and its size in proportion to the opening: this goes and joins itself to the second urn, as the still does to the first. The pipe of this second goes to a third, and the pipe of this last to the worm. The three urns bear each a small pipe of discharge towards the bottom.
This apparatus must be made with the greatest care. Neither the joints, the different pipes of communication, nor the nailings, must leave the smallest pa.s.sage to the vapors. The workman must pay the greatest attention to his work, and the distiller must lute exactly all the parts of the apparatus that are susceptible of it: he must be the more careful as to luting it, as this operation is only performed once a week, when the apparatus is cleaned. At the moment of the distillation, the master or his foreman must carefully observe whether there is any waste of vapors, and remedy it instantly. The still and urns ought to be well tinned.
CHAPTER XII.
EFFECTS OF THIS APPARATUS.
Although the still might contain 400 gallons, there must be only 200 gallons put into it: the rest remaining empty, the vapors develops themselves, and rise. In that state, the vinous liquor is about one foot deep, on a surface of 20 feet square: hence two advantages--the first, that being so shallow, it requires but little fuel to boil; the second, that the extent of surface gives rise to a rapid evaporation, which accelerates the work. This acceleration is such, that six distillations might be obtained in one day. The spirit contained in the vinous liquor rises in vapors to the lid of the still, there find the cap and its pipe, through which they escape into the first urn, by the side pipe above described, which conducts them to the bottom, where they are condensed immediately.
But the vapors, continuing to come into the urn, heat it progressively: the spirituous liquor that it contains rises anew into vapors, escapes through the cap and pipe, and arrives into the second urn, where it is condensed as in the first. Here again, the same cause produces the same effect: the affluence of the heat drawn with the vapors, carries them successively into the third urn, and from thence into the worm, which condenses them by the effects of the cold water in which it is immersed.
The urns, receiving no other heat than that which the vapors coming out of the still can transmit to them, raise the spirit; the water, at least the greatest part of it, remains at the bottom: hence, what runs from the worm is alcohol; that is, spirit at 35. It is easily understood how the vapors coming out of the still are rectified in the urns, and that three successive rectifications bring the spirit to a high degree of concentration: it gets lower only when the vinous liquor draws towards the end of the distillation. As soon as it yields no more spirit, the fire is stopped, and the still is emptied in order to fill it up again, to begin a new distillation.
Each time that the vinous liquor is renewed in the still, the water contained in the urns must be emptied, through the pipes of discharge at the bottom.
Metals are conductors of the _caloric_. The heat acc.u.mulated in the still, rises to the cap, from whence it runs into the urns: with this difference--that the pewter, of which the cap and pipes are made, transmits less caloric than copper, because it is less dense: and that bodies are only heated in reason of their density.
However, a great deal of heat is still communicated to the worm, and heats the water in which it is immersed. I diminish this inconvenience by putting a wooden pipe between the worm and the pipe of the third urn.
Wood being a bad conductor of caloric, produces a _solution of continuity_, or interruption between the metals. The wood of this pipe must be soft and porous, and not apt to work by the action of the fire: however, to avoid its splitting, I wrap it up in two or three doubles of good paper, well pasted, and dried slowly. This pipe is one foot long, and hollowed in its length, so as to receive the pewter pipe of the third urn at one end, and to enter the worm at the other; thereby the worm is not as hot, since it only receives the heat of the vapors which it condenses.
Notwithstanding all these precautions, it heats the water in which it is immersed after a length of time; and whatever care may be taken to renew it, all the vapors are not condensed, and this occasions a loss of spirit. I obviate this accident, by adding a second worm to the first: they communicate by means of a wooden pipe like the above. The effect of this second worm, rather smaller than the first, is such, that the water in which it is plunged remains cold, while that of the first must be renewed very often. By these means, no portion of vapors escape condensation. The liquor running from the worm is received into a small barrel, care being taken that it may not lose by the contact of the air producing evaporation.
CHAPTER XIII.
OF FERMENTS.
They are of two kinds; the very putrescent bodies, and those supplied by the _oxigen_. Animal substances are of the first kind: _acids_, neutral salts, rancid oils, and metallic _oxids_, are of the second.
Were I obliged to make use of a ferment of the first cla.s.s, I would choose the glutinous part of wheat flour. This vegeto-animal substance is formed in the following manner:--A certain quant.i.ty of flour is made into a solid dough, with a little water. It is then taken into the hands, and water slowly poured over it, while it is kneaded again. The water runs white, because it carries off the starchy part of the flour; it runs clear after it is washed sufficiently. There remains in the hands of the operator a dough, compact, solid, elastic, and reduced to nearly the half of the flour employed. This dough, a little diluted with water, and kept in the temperature indicated for the room of fermentation, pa.s.ses to the putrid state, and contracts the smell of spoiled meat. Four pounds of this dough per hogshead, seem to me to be sufficient to establish a good fermentation. A small quant.i.ty of good vinegar would answer the same purpose, and is a ferment of the second cla.s.s.
But are those means indispensable with my process? I do not think so.
1st. The richness of my vinous liquor, and the degree of heat to which I keep it, tend strongly to make it ferment. In fact, the infusion of the grain, by taking from it its saccharine part, takes likewise part of its mucilaginous substance, which is the principle of the spirituous fermentation, which it establishes whenever it meets with the other substance.
2dly. The hogsheads themselves are soon impregnated with a fermenting principle, and communicate it to the liquor that is put into them.
3dly. The rum distiller employs advantageously the residue of his preceding distillation, to give a fermentation to his new mola.s.ses: this residue has within itself enough of acidity for that purpose. Might not the residue of the distillation of my vinous liquor have the same acidity? It contains only the mucilaginous substance already acidulated.
Some gallons of that residue to every hogshead, would, I think, be a very good ferment.
Lastly. Here is another means which will certainly succeed: it is to leave at the bottom of each hogshead three or four inches of the vinous liquor, when transported into the still for distilling. This rising, which will rapidly turn sour, will form a ferment sufficient to establish a good fermentation.
The intelligent manager of a distillery must conduct the means I indicate, towards the end which he proposes to himself, and must carefully avoid to employ as ferments, those disgusting substances which cannot fail to bring a discredit on the liquor in which they are known to be employed.
CHAPTER XIV.
OF THE AREOMETER, OR PROOF BOTTLE.
This instrument is indispensable to the distiller: it ascertains the value of his spirits, since it shows the result of their different degrees of concentration. I will give the theory of this useful instrument, as it may be acceptable to those who do not know it.
Bodies sink in fluids, in a _compound ratio_ to the volume and the density of those fluids, which they displace. It is from that law of nature, that a ship sinks 20 feet in fresh water, while it sinks only about 18 feet in sea water, which has more density on account of the salt dissolved therein.
The reverse of this effect takes place in fluids lighter than water, as bodies floating in them sink the more, as the liquor has less density.
Upon those principles are made two kinds of areometers--one for fluids denser than water; the other for those that are lighter: the first are called _salt proof_; the second _spirit proof_. Distilled water is the basis of those two scales: it is at the top for the _salt proof_, and at the bottom for the _spirit proof_; because the first is ascending, and the other descending; but by a useless singularity, the distilled water has been graduated at 10 for the spirit proof bottle, and at 0 for the _salt proof_. We shall only dwell upon the first, because it is the only one interesting to the distiller.
Water being graduated at 10 in the areometer, it results from thence that the spirit going to 20, is in reality only 10 lighter than water; and the alcohol gaaduated [TR: graduated] at 35, is only 25 above distilled water.
The areometer can only be just, when the atmosphere is temperate; that is, at 55 Fahrenheit, or 10 Reaumur. The variations in cold or heat influence liquors; they acquire density in the cold, and lose it in the heat: hence follows that the areometer does not sink enough in the winter, and sinks too much in the summer.
Naturalists have observed that variation, and regulated it. They have ascertained that 1 of heat above temperate, according to the scale of Reaumur, sinks the areometer 1/8 of a degree more; and that 1 less of heat, had the contrary effect: thus the heat being at 18 of Reaumur, the spirit marking 21 by the areometer, is really only at 20. The cold being at 8 below temperate, the spirit marking only 19 by the areometer, is in reality at 20. 2-1/4 of Fahrenheit corresponding to 1 of Reaumur, occasion in like manner a variation of 1/8 of a degree: thus, the heat being at 78-1/2, the spirit thus marking 21, is only at 20; and the cold being at 87, the spirit marking only 19 by the areometer, is in reality at 20.
It is easily conceived, that extreme cold or extreme heat occasion important variations. For that reason, there are in Europe inspectors, whose duty it is to weigh spirits, particularly _brandy_: for that purpose they make use of the areometer and the thermometer. An areometer, to be good, must be proved with distilled water, at the temperature of 55. Areometers, being made of gla.s.s, are brittle, and must be used with great care. This inconvenience might be remedied, by making them of silver; I have seen several of this metal. A good silversmith could easily make them; I invite those artists to attend to that branch of business; it might become valuable, as the distillers will be more enlightened.
CHAPTER XV.
ADVANTAGES OF MY METHOD.