1080 VINEGAR 



neighbourhood is limited, the hydrogen seizes upon its equivalent to the exclusion of 

 the carbon, which, therefore, remains, and constitutes soot. Exactly in the same way 

 the hydrogen of the alcohol in the wash oxidises to the exclusion of the carbon, and 

 vinegar is formed from the remaining or carbonaceous element, which becomes itself 

 slightly oxidised. 



From this explanation it follows that, as the oxidation of the hydrogen generates 

 heat, there ought to be a very appreciable rise in the temperature during the pas- 

 sage of the wort through the acetifier. And, in practice, this is found to be the 

 case ; so that precautions are needed to prevent the heat from rising so high as to 

 vaporise the remaining alcohol of the wash. The temperature sought to be ob- 

 tained is about 90 to 92 Fahr., at which oxidation goes on freely, and the loss of 

 alcohol is moderate. In using the word ' moderate,' we speak practically rather than 

 chemically : for, in reality, the loss is very serious with strong worts. From practical 

 results, conducted with more than ordinary care, it has been ascertained that about 

 one-third of all the extractive matter of the malt and grain is lost or dissipated during 

 the processes of fermentation and acetification. Thus, a wort having a specific gravity 

 of 1'072, or, in technical language, weighing about 26 Ibs. per barrel, affords vinegar 

 containing 5'4 per cent, of pure acetic acid, and a residuary extract of 10 Ibs. from 

 36 gallons. The former of these would indicate 35 Ibs. of sugar or 13'7 Ibs. per 

 barrel of gravity ; whilst the latter shows 3 - 8 Ibs. per barrel ; the two united being 

 only 17'5 Ibs. instead of 26, the original weight. The loss, therefore, has been 8'5 Ibs., 

 or from a specific gravity of 1'072 to less than I'OoO. This prodigious destruction of 

 extract seems to imply that great improvements may yet take place in the manufacture 

 of vinegar. 



The manufacture of vinegar, by Ham's process, is an extremely interesting opera- 

 tion, and, 'when conducted with proper care, furnishes results of the most satisfactory 

 and uniform character. These, however, are not to be obtained without a vast 

 amount of experience and the most vigilant attention on the part of the manufacturer. 

 Thus a difference in the water, in the malt, in the mode of washing, in the cooling of 

 the wort, or in the fermentation of the wort, will each give rise to modifications in 

 the acetifying process which no subsequent skill or labour can rectify. There 

 seems no doubt that the most important points in Ham's method are the cooling 

 and fermentation of the wort ; though, where perfection is sought for, no one of 

 the other conditions can be omitted or neglected with impunity. We shall, therefore, 

 proceed to treat of these conditions seriatim, rather than in the order of their import- 

 ance. At first sight it might be supposed that the purer the water the better ; that is 

 to say, the less the amount of earthy or saline constituents, the more valuable the 

 water would be for making vinegar. Experience, however, teaches us the contrary ; 

 and science confirms the truth of this teaching, by pointing out the real nature of the 

 operation. When pure water is made to act at a high temperature upon the ordinary 

 ingredients of a vinegar-maker's mash-tun, it is not alone the sugar, gum, and starch 

 of the grain which enters into solution, for, under such circumstances, the gluten is 

 also dissolved ; but this gluten is composed of vegetable albumen and vegetable 

 gelatine, the former of which, as is well known, is capable of being decomposed and 

 precipitated by many earthy and metallic salts, of which the sulphate of lime is one. 

 If, therefore, this salt exists in the water employed for the fabrication of vinegar, or of 

 ale or beer, the wort will contain little or no vegetable albumen ; consequently, the 

 vinegar or beer made with such water never becomes cloudy or ropy, as happens 

 when pure water is iised, for these defects arise from an excess of albuminous 

 matter. The water used for making the celebrated Burton ale contains a great deal 

 of sulphate of lime ; and the spring-water of Worcester, which is employed by the 

 extensive firm of Hill, Evans, and Co., in that city, vinegar-makers, contains also a 

 very large amount of sulphate of lime, and no doubt contributes much towards 

 maintaining the well-established reputation of that firm. Whenever, therefore, much 

 sulphate of lime exists in water, without the presence of any noxious ingredient, such 

 water may always be relied upon as favourable for the production of good beer and 

 vinegar. 



As regards the malt, or rather the mixture of malt and grain, employed for the pro- 

 duction of wort, the common Scotch distillers' formula is the best, containing, as it 

 always does, a considerable percentage of oats, for the long husk of the oat greatly 

 facilitates the operation of draining, and thus secures the thorough separation of the 

 wort from the spent grains. 



In practice it is found necessary to ferment only two gravities, a high and a low, 

 all the other qualities of vinegar being made by mixing or diluting these after 

 acetification. The most common, and unquestionably the best, gravity for fermonta- 

 tion is that which in technical language weighs about 20 Ibs., or has a specific gravity 

 of rOoC; tho other, or that intended for strong or proof vinegar, being of specific 



