FABRICATION OF WIXE-VIXEGAR. 177 



actually fit for the preparation of wine-vinegar, wine attacked by 

 " acetous degeneration ," i. e., wine already so much changed by 

 the vinegar ferment as to render it unfit for a beverage, and, 

 further, wine which though not sick is unsound, showing a taste 

 of mold, of the barrel, etc. 



Wine no longer young and not overly rich in alcohol is espe- 

 cially adapted for the nourishment of the vinegar ferment. Such 

 wine need only be exposed to a somewhat higher temperature in 

 order to induce acetous fermentation, which, if not disturbed in its 

 progress, will finally convert all the alcohol in the wine to acetic 

 acid. 



It may here be remarked that every normal wine always con- 

 tains, besides the bodies belonging to the series of fatty acids, 

 acetic acid, though only about a few ten-thousandths of its weight. 

 By storing the wine, the acetic acid does not increase, but becomes 

 rather less, it being consumed in the formation of compound 

 ethers. Hence, a rapid increase of the acetic acid is an indica- 

 tion of the wine being attacked by acetous degeneration, and if 

 examined with the microscope the ferment characteristic of 

 acetous fermentation will be found upon its surface. Many 

 remedies have been proposed for the cure of acetous degenera- 

 tion, but none of them is of any value except heating the wine to 

 about 140 F., whereby the vinegar ferment is killed and the 

 further progress of acetous fermentation checked. There is, 

 however, absolutely no remedy for the removal or neutralization 

 of the acetic acid already present in the wine. Heating the wine 

 can only be recommended when the evil has been in existence 

 but a short time and the increase of acetic acid can be de- 

 tected only by a very sensitive tongue. Mixing wine attacked by 

 acetous degeneration with sound wine in order to cover up the 

 acid taste is especially unadvisable ; nothing can be attained by 

 it except a short delay in the reappearance of the evil and the 

 transmission of the infection to the sound wine. There are but 

 two ways in which wine attacked by acetous degeneration can be 

 in anywise profitably utilized : by employing it for the preparation 

 of cognac or converting it into wine- vinegar. For the first a dis- 

 tilling apparatus is required, and, consequently, cannot be effected 

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