154 VINEGAR, CIDER, AND FRUIT-WINES. 



this prejudice is, the manufacturer is nevertheless obliged to re- 

 cognize it and color his vinegar by artificial means. This is best 

 effected by caramel or burnt sugar prepared from glucose, which 

 is entirely harmless. It is best prepared by melting the glucose 

 in a shallow iron vessel over a fire, stirring constantly with a 

 long-handled spoon. The melted mass soon browns and rises in 

 the vessel. The conversion of the sugar into caramel being much 

 hastened in the presence of an alkaline body, 1J to 2 per cent, of 

 the weight of the glucose used of pulverized ammonium carbonate 

 is added at this stage. The mass is now heated with constant 

 stirring until it becomes black, runs from the spoon in viscous, 

 dark brown threads, and a sample dropped upon a cold surface 

 congeals to a black mass impervious to light except on the edges. 

 The vessel is then lifted from the fire and the contents poured out 

 upon metal or stone plates. The taste of the congealed mass 

 should not be bitter or at least only slightly so. On exposure to 

 the air the caramel deliquesces to a thick black fluid, and, hence, it 

 should immediately after its preparation be converted with water 

 into a solution of the consistency of syrup, such concentrated solu- 

 tion keeping better than a dilute one which easily molds. Im- 

 mediately before use the solution is diluted with water, and enough 

 of it added to the vinegar to give it the desired coloration. 



CHAPTER XVI. 



PREPARATION OF VINEGAR FROM VARIOUS MATERIALS. 



SINCE acetic acid is formed by the oxidation of alcohol, vine- 

 gar can, of course, be prepared from every fluid containing alco- 

 hol, such as beer, wine, cider, as well as from the juice of saccha- 

 riferous fruits which has passed into alcoholic fermentation. By 

 allowing grain to germinate, a body, to which the term diastase is 

 applied, is formed which possesses the property of converting starch 

 into fermentable sugar and dextrin when brought into contact 

 with it under certain conditions. Vinegar can, therefore, be pre- 

 pared from starch though in a round-about way by treating 



