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The Clarification on Liquids by Fining

kind of cloth which carries down with it all the impurities suspended in the wine. Sulphuric acid is frequently added to weak liquors for a similar purpose, either alone, or after the addition of white of egg, or isinglass, both of which it rapidly throws down in an insoluble form. A pernicious practice exists among some unprincipled parties of using certain salts of lead and potash to clear their liquors; especially those that are expected to sparkle in the glass, as cordial gin and hock wine. For this purpose, a little sugar of lead, dissolved in water, is first mixed up with the fluid, and afterwards a little more than one half its weight of sulphate of potash, also dissolved in water, is added, and the liquor is again "roused up." By standing, the sulphate of lead, formed by this mixture, subsides and leaves the liquor clear. No person should attempt to fine by this process, as the ingredients used are pernicious poisons. Bullock's and sheep's blood is used in the same way as isinglass or white of eggs, for fining red wines, beer and porter. Blood, however, is very apt to communicate a slightly unpleasant odor or flavor to wine. Lime, alum, alcohol, the acids, and heat, act by curdling or coagulating the feculencies or impurities, and thus, by increasing their density, induce their subsidence. Plaster of Paris acts partly like the above, and partly like albumen or gelatine, by enveloping and forcing down the suspended matter. Gum arabic has this advantage over most ingredients used for fining, it is not liable to putrefaction. Ropy, stringy wine can only be clarified by the addition of tannin, as specially directed in another place. (See "To Remedy Ropiness in Wine.") Infusion, Maceration, and Digestion.

In order to extract the soluble principles in substances which cannot be advantageously distilled, liquor dealers are often obliged to resort to infusion. This consists in submitting them for a greater or less period of time to the action of any liquid, with or without the aid of heat. This is known by the name of infusion, digestion, or maceration, terms all signifying the same process with different modifications in the way of conducting it. When the principles to be extracted are soluble in water, and at the same time but slightly volatile, boiling water is poured on the substance of which the infusion is required, the vessel is carefully covered, and the whole allowed to remain untouched for some minutes or even some hours, according to the greater or less penetrability of the substance, and the required strength of the infusion; the result is an INFUSION, properly so called. If an infusion is required of dried leaves or flowers, they are first moistened with a little boiling water, and a little time allowed for them to swell and soften before adding the rest of the water. Infusions made by adding all the water at once, as is still frequently practiced, are deficient both in flavor and perfume.

MACERATION. - When an infusion is made without the aid of heat, it is termed maceration. This takes a much longer time than an infusion, properly so called; it rarely requires less than a day, sometimes several weeks.

Those substances to which heat would be injurious, or which are easily soluble, are treated in this way. In many distillations this method is made use of to soften the substances before putting into the still; and, to facilitate the extraction of their odorous principle, liquor manufacturers macerate in pure alcohol the plants whose odorous principles they wish to extract, in order to preserve them till they are required for distillation. Compound wines and toilet and table vinegar are prepared by maceration, these liquors being readily decomposed by heat; any other method would be ineffectual.

DIGESTION is a prolonged infusion which is usually conducted at a medium temperature between that required for an infusion, properly so called, and that of a maceration. Its object is usually to impregnate the alcohol with the principles of a substance which would be but slowly extracted without the aid of a certain amount of heat, such as that of the sun, or of hot ashes. Mixing together two or more liquors and allowing them to stand for some days, is also called digestion. Infusions, whether made with or without heat, should be made in vessels which cannot be attacked by any of the substances with which they are in contact, and closed sufficiently tight to prevent the loss of the most volatile principles.

The tin cucurbit, with cover, is, in the two respects, best adapted for infusions in water. Maceration and digestion are usually performed in vessels of stoneware or glass, which are placed on the sand-bath * when a regular and uniform heat is required.

Whatever may be the form or nature of the vessels employed, care must be taken not to fill them full, also to cover those which are to be placed on the sand-bath * The Sund Bath is usually an iron pot, or a shallow vessel of sheet iron, capable of holding sand to the depth of four or six inches . It serves to regulate the action of the heat on vessels which do not bear a rapid change of temperature, such as glass or stoneware. It is It is heated to the required degree by being placed over the fire of a fur- The sand used in the bath should be good sea or river sand, thoroughly washed, to remove all dirt, and dried. nace. with a damp piece of parchment tightly tied round the top, with many pin holes pricked in it. If this double precaution is neglected, the increased volume produced by the heat and also the expansion of the air may burst it. Moreover, the process is never so well conducted in a vessel that is too full.

It is also necessary to break and bruise down, in some convenient way, the substances from which the infusion is required, in order that a large surface may be simultaneously exposed to the action of the liquid, to agitate from time to time the vessel in which it is contained, to present fresh surfaces, to proportion the length of the operation to the degree of consistence of the substances employed; lastly, to treat each by that particular mode of infusion best adapted to its nature.

In order that the different substances which are to enter into the composition of a liquor, produced by infusion, may all be acted on to the same extent, the infusion must be commenced with the hardest substances, to which those which are softer must be added, when the first are considered sufficiently softened. Without this precaution the latter would furnish a great deal too much to the infusion, while the former would not contribute sufficient. In certain cases the substances to be infused must be used whole; this is when the most important principle is contained in the exterior.

The time employed for an infusion should be proportioned to the character and solubility of the principles to be extracted; the odorous principle, for instance, being usually the most soluble of all, particularly in alcohol, it is better, when that is principally desired, to shorten the time, in order to get a milder product; for both cold and hot infusions give thick and sharp liquors, when carried on too long.

It is therefore usually found that with few exceptions the quicker an infusion is made the better, and this is especially the case with all rectafias or cordials, except those made from sweet fruits.

When it is considered that the infusion has been carried on long enough, the liquor must at once be drawn from the marc or residue, either by passing it through a sieve or a wet cloth, if it is necessary to press it. Those substances which absorb much liquid, or those of which the most important principle is not contained in the exterior, are squeezed either by hand or in a press. In other cases this is avoided.

In order to have fine and clear extracts, they are then filtered.

To produce tinctures of high perfumes and not overcharged with color, spirit of 80° per cent must in general be employed, then macerate for a week at a tempera ture of 65° Fahrenheit. But if a saving of time is an ob ject, stronger spirit may be used, and a heat maintained of 100° Fahrenheit, taking care to stir from time to present fresh surfaces to the action of the spirit, then, after letting stand for some hours, it is drawn off with pressure, if necessary, and carefully filtered. Tinctures improve with age by a kind of more intimate combination which takes place between the different principles of which they are composed, but they must be preserved in flasks, well corked, and stored in a place neither too hot nor too cold; the light ultimately occasions a species of decomposition. It may be observed that tinctures show a degree of strength, as marked by the hydrometer, inferior to that of the spirit originally employed, in the same proportion as the strength of the tincture, but this change is only due to the substances they hold in solution, and which add to their specific gravity, without there having been any real loss of strength, unless very succulent substances have been macerated in it.

Well prepared tinctures have this advantage over distilled spirits, that they preserve without change the perfume and the flavor of the substances they hold in solution; they retain the aroma of some which yield none by distillation, have no fiery or empyreumatic taste, and lastly, their preparation is less troublesome, and more economical both as regards the process employed and the manufacture.

These processes would therefore be equally convenient and agreeable in the manufacture of fine liquors; all that would be necessary would be to have in stock tinctures of the aromatic substances in most demand, and combine them as wanted, in the proportions necessary to make an agreeable mixture. Liquors, cordials, etc., thus prepared would gain much in perfume, taste and softness; moreover, age would not be so essential to them, and the use of tinctures would be more economical than that of spirits.

Notwithstanding these advantages, their usually deep color prevents them from being used for liquors which are required to be perfectly white, or which are to be colored at will. But, supposing that they are not on this account adapted for the making of fine liquors, they can, at least, be useful in the manufacture of spirits; all that has to be done is to make an extract of the required substance, and then distill it by means of a water-bath till nearly all the spirit has come off; what remains in the still is worthless.

The principal advantages of this method over the distillation of substances in their native state, would consist in obtaining better products by only distilling the most delicate portions of these substances, which would require a less extensive apparatus for distilling. In order to thoroughly understand the properties of tinctures, it must be remembered that alcohol, whatever may be its strength, unless it be absolute, is also combined with a certain portion of water. Vegetables, on the other hand, are composed of essential oil, resin, salts, extractive coloring matter, etc., in different proportions, all substances of which the one only dissolves in water and the others in alcohol. Thus, when any substance is macerated in any spirituous liquid, the alcohol only dissolves the essential oils and the resins; the water dissolves the other principles to the fullest extent possible. It is therefore evident, that if, other things being equal, a large quantity of the same substance is macerated in 90° alcohol, and in ordinary proof spirit, the first tincture will be much finer both in smell and taste while, on the other hand, the other will be more highly charged with color. This simple example will serve to show that the strength of the spirit to be employed is not immaterial, and should be dependent on the nature of the tincture required. Tinctures prepared by simple maceration in the cold are better than those prepared by heat, but very hard substances require that assistance if the spirit employed is rather weak or a speedy result required. Tinctures prepared for the use of liquor manufacturers ought, for convenience of use, to be saturated as much as possible, and prepared with spirits of wine, in order to be more odorous and less colored. As it is better to employ too much than too little of the aromatic substances, and the first maceration does not exhaust them, a weaker spirit may be poured over the marc to produce an inferior tincture, which, however, will still contain much of the aromatic principles.

It would be useful to specify positively the quantity of aromatic substances that can be exhausted by a given amount of spirit of wine, but as that depends essentially on the quality of the substances employed, the degree of division, the strength of the spirit, and the temperature maintained, only very vague hypotheses could be given. PART II.

THE HYDROMETER AND ITS USES, WTH EXPLANATORY TABLES DIAGRAMS, AND COMPARATIVE SCALE, TOGETHER WITH SOME OBSERVATIONS ON THE