CLARIFICATION

The act of clearing or making bright; commonly applied to the proce of ‘clearing’ or ‘fining’ the liquids by chemical means, instead of by filtration. The substances used for this purpose are popularly known as ‘clarifiers’ or ‘finings.’ The substances employed in the clarification of liquids operate by either mechanically embracing the feculous matter, and subsiding with it to the bottom of the ve el, or by inducing such a change in its nature or bulk that it subsides by its own density, in each case leaving the liquor transparent. Albumen, gelatin, the acids, certain salts, blood, lime, plaster of Paris, alum, heat, alcohol, ., serve in many cases for this purpose. The first is used, under the form of white of egg, for the clarification of syrups, as it combines with the liquid when cold, but on the application of heat rapidly coagulates and rises to the surface, carrying the impurities with it, forming a scum which is easily removed with a skimmer. It is also much used for fining wines and liqueurs, particularly the red wines and more limpid cordials. Gelatin, under the form of isingla , di olved in water or weak vinegar, is used to fine white wines, beer, cider, and similar liquors that contain a sufficient quantity of either spirit or astringency (tannin), to induce its precipitation. Sulphuric acid is frequently added to weak liquors for a similar purpose, either alone or after the addition of white of egg or gelatin, both of which it rapidly throws down in an insoluble form. A pernicious practice exists among some unprincipled manufacturers of using certain salts of lead and potash to clear their liquors; especially those that are expected to sparkle in the gla , as ‘cordial gin,’ . For this purpose a little sugar of lead, di olved in water, is first mixed up with the fluid, and afterwards a little more than half its weight of sulphate of pota a, also di olved 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. Bullock’s blood is used in the same way as isingla or white of eggs, for fining red wines, beer, and porter. Lime, alum, alcohol, acids, and heat, act by curdling or coagulating the feculencies, and thus, by increasing their density, induce their subsidence. Plaster of Paris acts, partly like the above, and partly like albumen, or gelatin, by developing and forcing down the suspended matter. Sand is often sifted over liquors (especially cordials and syrups), for the simple purpose of acting by its gravity, but appears to be quite usele , as it sinks too rapidly. The juices of plants are clarified by heat, which coagulates the albumen they contain. Marl or clay is frequently used to clear cider and perry. A strip of isingla is generally employed to clarify coffee. See Wine, Brewing, Cordials, Coffee, Finings, Infusion , .