Domestic Encyclopædia (1802)/Clarification

CLARIFICATION, is the act of clearing or fining liquids from heterogeneous or feculent ingredients. For this purpose, the whites of eggs, blood, and isinglass, are usually employed: the two first, for clarifying liquors, while boiling hot; the last, for those which are to be fined when cold; as wine, ale, &c. The whites of eggs are beaten up into a froth, mixed with the liquor, and united with the impure particles floating on it; which soon indurate, and are carried up to the surface, in the form of an insoluble scum. Blood operates in a similar manner, and is principally used in the processes of refining salt and sugar.

Great quantities of isinglass are consumed in fining turbid wines. A solid piece,, about a quarter of an ounce, in weight, is put into a cask of wine, where it gradually dissolves, and forms a skin upon the, surface: this pellicle at length subsides, carrying down with it the feculent matter that floated on the wine. Other vintners previously dissolve the isinglass; and, having boiled it down to a gelatinous consistence, mix it with the liquor, strongly agitate the cask, and then let it stand to settle. It deserves, however, to be remarked, that wines treated in this manner are tainted with a very putrescent animal substance, and cannot be wholesome.