114 VINEGAR, CIDER, AND FRUIT- WINES. 



as vinegar eels, which frequently become very annoying in vine- 

 gar factories, reach the alcoholic liquid through the use of river 

 water, and, therefore, the use of well-water wherever possible is 

 recommended. 



The constitution of the spirits of wine used in the preparation 

 of the alcoholic liquids is of great importance, the bouquet of 

 the vinegar to be prepared depending on it. Commercial spirits 

 of wine always contains certain foreign bodies known as " fusel 

 oils ;" they have a very intense odor and can only be removed by 

 careful rectification. For the vinegar manufacturer it is of great- 

 importance to know the behavior of spirits of wine containing 

 fusel oil when converted into acetic acid, and a number of experi- 

 ments with different varieties (from potatoes, grain, wine) have 

 shown the respective vinegar also possessed of a specific odor, 

 differing, however, from that of the original fusel oil and develop- 

 ing by storing into a bouquet of a peculiar but agreeable scent. 

 This phenomenon is explained by the fact that the energetic 

 oxidizing process which takes place in the generators extends not 

 only to the alcohol but also to the other bodies present, and the 

 greater portion of the fusel oils is thereby converted into odori- 

 ferous combinations or compound ethers. 



By treating potato fusel oil (amyl alcohol) with sulphuric acid 

 and an acetate, amyl acetate is formed which in a diluted state 

 smells like jargonelle pears and is used by confectioners under the 

 name of " pear essence" for flavoring so-called fruit bonbons. 

 The same process would seem to take place by passing spirits of 

 wine containing potato fusel oil through the generators ; the vine- 

 gar prepared from such spirits of wine shows an agreeable scent 

 immediately when running off from the generators, while vinegar 

 prepared from entirely pure spirits of wine has at first a stupe- 

 fying smell and acquires a harmonious odor only by long storing. 



It would, therefore, be advisable for the manufacturer who 

 works with potato alcohol not to use the highly rectified product, 

 but a mixture of it and of crude spirits containing fusel oil, 

 the vinegar prepared from such a mixture acquiring a more agree- 

 able odor than that obtained from the rectified product. How 

 much of the crude spirits has to be used can only be determined 



