VINEGAR is the name of an acid liquor pre pared from wine, cider, beer, and other liquors, and more recently from the distillation of wood. What ever be the materials from which common vinegar is to be made, it is only necessary to admit air into the vessel in which it is to be kept, and to keep it at a temperature from 75° to 80° in this climate, in order to obtain vinegar. The different kinds of vinegar are four, wine vinegar, mall vinegar, sugar vinegar, and wood vinegar.
Wine vinegar is made in the following manner: the wine, when mixed with a quantity of wine lees, is transferred from the tun into cloth sacks, placed svithin a large iron-bound vat. The liquid is ex pressed from the sacks by pressure, and the fluid thus obtained is put into large casks with a hole in their top, and placed upright. In summer they ate exposed to the sun, and in winter to a stove. In a few days fermentation takes place. If the heat now becomes too high, it must be lowered by coolers, and the addition of a little fresh wine, as the excel lence of the vinegar depends on the fermenting tem perature. The process is generally complete in a fortnight in summer, and a month in winter. The vinegar is then run off into barrels containing seve ral chips of birch wood. In a fortnight more it will be found clear and fit for sale. It must now, how ever, be kept in close casks.
Vinegar is usually made from malt in this coun try. One boll of malt, masked in hot water, will yield 100 gallons of wort in less than two hours. When the temperature has fallen to 75°, four gal lons of the harm of beer are added. At the end of 36 hours, it is transferred to casks, which are laid on their sides, and exposed, with their bung-holes loosely covered, to the sun or to stoves. In three months this vinegar is ready, when it is to be used for making sugar of lead; when it is wanted, how ever, for domestic use, the above liquor is put into upright casks, having a false cover perforated with holes, fixed about a foot from the bottom; on this cover is laid a considerable quantity of rape, or the refuse from the manufacturers of British wine, or for want of this, a quantity of low priced raisins.
The liquid is turned into another barrel every 24 hours, in which time it has begun to grow warm. The vinegar is sometimes fully fermented without the rape, which is added towards the end of the process, to give flavour.
Sugar vinegar may he made from a weak solu tion of 18 ounces of sugar to every gallon of water. Yeast and rape are next to be added, and whenever the process is complete, as the taste and flavour will indicate, it is to be decanted into barrels or bottles. A momentary boiling before bottling, is favourable to its preservation.
Wood vinegar, or the pyroligneous acid, is ob tained by subjecting wood to a strong red heat, in iron retorts. The best woods are oak, ash, birch, and beech. The liquor obtained is a crude vinegar contaminated with tar, the residuary charcoal be ing only one-fifth of the wood distilled. This crude acid is rectified by a second distillation in a copper still, by which 20 gallons (out of 100 of crude acid) of a viscid tarry matter arc separated. It is now a transparent brown liquid, with an empyreumatic smell, and a specific gravity of 1.013. When re distilled, saturated with quick lime, evaporated to dryness, and greatly torrefied, the empyreumatic matter is dissipated, so that by decomposing the calcareous salt with sulphuric acid, a pure and per fectly colourless vinegar, agreeable to the taste, is obtained by distillation. See Dr. Ure's Dictionary of Chemistry, article ACID, Acetic. See also our ar ticle CHEMISTRY, VOl. V. p 696.