1076 VINEGAR 



casks must be cleared out. This renovation usually takes place every 10 years; but 

 the casks, when made of -well-seasoned oak and bound with iron hoops, will last 25 

 years. The wine, as well the vinegar produced, should be clarified by being slowly 

 filtered through beech-chips, closely packed in a, large open tun. When wines are now, 

 and somewhat saccharine or too alcoholic, they acetify reluctantly, and need the addi- 

 tion of a little yeast, or even water, to the mixture ; and when they are too weak, they 

 should be enriched by the addition of some sugar or stronger wine, so as to bring them 

 to a uniform state for producing vinegar of normal strength. To favour the renewal 

 of fresh air into the upper pa'rt of the hogsheads, it would be advisable to pierce a 

 two-inch hole near to the upper level of the liquid when the cask is fullest, by which 

 means the heavy carbonic acid would fall out, and bo replaced by the atmospheric air 

 at the superior apertures. 



Wine vinegar is of two kinds, white and red, according as it is prepared from white 

 or red wine. White wine vinegar is usually preferred, and that made at Orleans is 

 regarded as the best. 



Dr. Ure found its average specific gravity to be 1-019, and to contain from 6$ to 7 

 per cent, of real acid ; according to the Edinburgh Pharmacopseia, its specific gravity 

 varies from 1-014 to 1-022. 



2. MALT VINEGAR. (British Vinegar; in Germany called Malz-Getreide- or Bler- 

 essig.) In England vinegar is chiefly made from an infusion of malt, by first ex- 

 citing in it the alcoholic fermentation, and subsequently inducing the oxidation of the 

 alcohol into acetic acid. 



For details of the processes of malting and brewing the alcoholic liquor, we must 

 refer to the special articles on these subjects, confining our attention here more es- 

 pecially to the latter stages of the operation. 



From 6 bushels of malt, properly crushed, 100 gallons of wort may be extracted 

 by due mashing, the first water of infusion being of the temperature of 160 Fahr., 

 and the next two progressively hotter, for exhausting the soluble saccharine matter. 

 When the wort is cooled to 75, from 3 to 4 gallons of good yeast are stirred into it in 

 the fermenting tun, and when it has been in brisk fermentation for about 40 hours, 

 it is ready for transference into the vessels in which the acetification is to be accom- 

 plished. 



The transformation of the fermented wort into vinegar was formerly effected in two 

 ways, which were entirely opposite in their manner of operation. In one case the 

 casks containing the fermented malt infusion (or gyle) were placed in close rooms, 

 maintained at a uniform temperature, as already described in the preparation of wine 

 vinegar ; in the other, they were arranged in rows in an open field, where they re- 

 mained many months. As regards the convenience and interests of the manufacturer, 

 it appears that each method had its respective advantages, but both are now almost 

 entirely abandoned for the more modern processes to be described : a short notice of 

 the fielding process is, however, retained. 



When fielding is resorted to, it must be commenced in the spring months, and then 

 left to complete itself during the warm season. The fielding method requires a 

 much larger extent of space and utensils than the stoving process. The casks are 

 placed in several parallel tiers, with their bung-side upwards and left open. Beneath 

 some of the paths which separate the rows of casks are pipes communicating witli 

 the ' back ' at the top of the brewhouse ; and in the centre of each is a valve, 

 opening into a concealed pipe. When the casks are about to be filled, a flexible 

 hose is screwed on to this opening, the other end being inserted into the bung-hole 

 of the cask, and the liquor in the ' gyle back' at the brewhouse, by its hydrostatic 

 pressure flows through the underlying pipe and hose into the cask. The hose is 

 so long as to admit of reaching all the casks in the same row, and is guided by a 

 workman. 



After some months the vinegar is made, and is drawn off by the following 

 operation : A long trough or sluice is laid by the side of one of the rows of casks, 

 into which the vinegar is transferred by means of a syphon, whose shorter limb is 

 inserted into the bung-hole of the cask. The trough inclines a little from one end to 

 the other, and its lower end rests on a kind of travelling tank or cistern, wherein the 

 vinegar from several casks is collected. A hose descends from the tank to the open 

 valve of the underground pipe, which terminates in one of the buildings or stores, and, 

 by the agency of a steam-boiler and machinery, the pipe is exhausted of its air, 

 and this causes the vinegar to flow through the hose into the valve of tlic pipe, and 

 thence into the factory buildings. By this arrangement the whole of tho vinegar is 

 speedily drawn off. From the storehouse, where the vinegar is received, it is pumped 

 into the refining or rape vessels. 



These rape vessels are generally filled with the stalks and skins of grapes or raisins 

 (tho refuse of the British wine manufacture is generally used), and the liquor being 



