VINEGAR is that form of ACETIC ACM (q.v.) which is generally preferred for culin ary purposes, and which is made by the fermentation of vegetable In Great Britain, it is manufactured on a large scale by the fermentation of malt; on the continent of Europe, it is as largely made from low wines which have turned sour Malt, or British vinegar, as it is sometimes called, is made by brewing a weak wort from malt exactly as for beer (q.v.). To 100 gallons of this, at a temperature of i are added 4 gallons of yeast, and well stirred through for 8 or 10 minutes. This mixture is then allowed to ferment actively for two days, and is then transferred to the stoving-room; here it is distributed into a number of tubs, which. when filled, are covered over with a coarse canvas. This room is dark, and is heated by stoves, and the heat is constantly sustained for weeks until the conversion of the wort into vinegar is complete. The pro cess of acetification is accelerated by introducing into the casks with the wort either the residuary fruit used in making domestic wine, or the foot stalks and skins of grapes. This rape, as it is called, acts as a kind of ferment. Other processes are used by differ ent manufacturers for the purpose of producing it quicker; but the minute description,. necessary to render them clear would be out of place here. Much vinegar is also made of beer which has become sour; it is, however, very inferior in quality, and wants the Agreeable flavor of malt vinegar prepared by the above process,which is due to the pres -ence of acetic and other ethers.
A rather insipid kind of vinegar is made by means of the vinegar-plant.(q.v.). The vinegar-plant itself may be produced thus: A solution of a quarter of a pound of sugar and half a pound of treacle in three quarts of water is first simmered, then poured into -a jar, covered up, and kept in a warm place for six weeks. The liquid becomes vine gar, and on the top there has been formed a scum-like fungus, which is the vinegar plant ; and by adding a piece of this to a similar solution, the process of conversion into vinegar now takes place in much less time. During the process, the plant thickens by 'the formation of a new layer on its under surface; and by peeling off this layer, and using it in a fresh operation, the plant may be propagated indefinitely, The greatest manufacture of wine vinegar in Europe is at Orleans, in France. Here the wines are sent from all parts when unfit for drinking, and are converted into vine gar. In the manufacture a large number of casks are used, with openings into each of only two inches diameter. Into each one are poured 100 pintS of vinegar boiling hot;
and to this, after eight days, are added 10 pints of sour wine, and this is repeated every 8 days until the cask is full; another 15 days completes the process, and the vinegar is ready for use. Beech-shavings are much used in vinegar-making, as they are assist in clarifying the liquor by attracting the lees, which settle upon them, and leave the liquor clear, in which state it acetifies more rapidly.
" According to Ure, a good vinegar may be prepared by adding to each gallon of a syrup composed of 11 lb. of sugar and 1 gal. of water, a quarter of a pint of yeast. If kept for three days at a temperature of 75° or 80°, it will be sufficiently acidified to allow of being drawn off into the refining-cask, where one ounce of bruised raisins and one ounce of crude tartar are to be added to each gallon of liquor. When the sweet taste has quite disappeared it should be drawn off into bottles, and corked down tightly. It is stated that such vinegar will contain 5 per cent of pure acetic acid."—Miller's Organic Chemistry, 2d ed. p. 339. Vinegar prepared by these methods contains a large amount of foreign matters, which can be got rid of by simple distillation; time acid liquid which comes over constituting what is known in pharmacy as distilled vinegar. What is sold commercially as distilled vinegar is simply ascetic acid distilled from wood (See PYRO LIGNEOUS ACID), and diluted with five times its volume of water. This constitutes also the vinegar used by pickle manufacturers ; it is quite as wholesome as common vinegar, i but wants its agreeable flavor ; its preservative powers are, however, much greater, and itsprice i pn ce very much less, if fairly charged. Vinegar containing five per cent of the pure acid is the strongest that is ever produced, and is termed proof 'vinegar. There are four kinds manufactured, which are known in trade by the numbers 18, 20, 22, and 24, the last being the best quality. The strength of any specimen is best ascertained by deter mining the quantity of anhydrous carbonate of soda which a given weight of it wilt neutralize, it being recollected that 100 grains of carbonate of soda correspond to 96.2 grains of anhydrous acid. The ammonia test, according to Neligan, serves to distin guish French from English vinegar: with the former, the color is purplish; with the lat ter. there is either no change, or it is brownish. There is generally a slight turbidity, which is due to a trace of lime.