VINEGAR MANUFACTURE. The re lation which vinegar bears to the acetic; and pyroligneous acids is noticed under ACETIC Acm. In countries which produce wine vine gar is obtained from the acetous fermentation of wine ; but in this country it is usually pro cured from malt, and the process employed resembles the first stages of the brewer's operations. [Brims-ENG.] The malt is ground and mashed with hot water. The wort, after"• being cooled, is transferred to the fermenting tun, where by the addition of yeast it under goes the acetous fermentation ; and when this is over the liquor is transferred to small ves sels, which are kept warm by means of a stove t in these it remains for a shorter or longer period, according to the temperature of the stove and the strength of the liquor. The process of acetification is assisted by intro. during into the casks with the wort what is called rape, which is a quantity of the residuary fruit which has served for making domestic wines, or has been preserved by the vinegar maker from one process to another in his own factory. The use of the rape is to act as an acetous ferment, and thus induce sourness in the wash, it being well impregnated with vinegar and continually kept sour. Acetifica tion is sometimes carried on by transferring the wort, after it has undergone the vinous fermentation, into casks, the bungholes of which are left open and loosely covered will tiles ; the casks are then exposed for a long time to the air ; but the use of stoves ha: greatly superseded this mode, has abridge( the time of tho operation, and rendered i less liable to failure. The vinegar, after i
has reached its greatest degree of sourness is rendered clear and fit for use either la: subsidence or by the employment of isinglass Vinegar may be prepared in small quantitie' from the fermentation of a solution of mixed with yeast ; or it may be obtained b: the fermentation of various fruits ; thus fit, juice of good apples contains a sufficiency o sugar to afford tolerably good vinegar withou any addition.
In Franco vinegar is made from poor wino and there are two kinds—the white, prepare' from white wine ; and the red, by the acetifi cation of the red wine : these are finer fla voured and somewhat stronger than the mal vinegar of this country.
Vinegar acts as an effectual preservative free the putrefactive fermentation of dead organi tissues, and is hence employed as the mean of forming pickles, or meat in a dried state, simply immersing the substance in it for few minutes. Wood vinegar, or pyroligneou acid, is most efficacious for this purpose owing to the creasote present in it. Crud pyroligneous acid is one of the most endue applications to timber, both to prevent the dr .rot and the ravages of insects. Concentrate, acetic acid acts on the living tissues as caustic poison ; applied to the skin it cause heat, redness, and rapid inflammation.