288 AGRICULTURAL BACTERIOLOGY. 



and they do not yet appear to have been adopted in any prac- 

 tical vinegar-making plant. But vinegar-makers have, to a 

 considerable extent, adopted rougher methods of obtaining the 

 vinegar organism in quantity and in a comparatively pure 

 condition. One simple method adopted is as follows : Filter 

 two parts of white spirit vinegar through fine bolting cloth 

 to remove the vinegar eels. Mix the liquid with ^ - part of 

 alcohol of 90 per cent, volume, and I part of white wine 

 which has been previously boiled, filtered and cooled. Place 

 this mixture in shallow dishes and cover with glass plates. 

 The vinegar organism appears in a few hours as a thin scum 

 which will ordinarily be pure, or nearly so. If the scum does 

 not show any white spots (molds) gently lower it upon the 

 surface of the vat containing the alcoholic solution which is to 

 be made into vinegar. The result is a comparatively pure 

 culture of vinegar organisms and a satisfactory fermentation. 

 When used in making vinegar from cider, this process gives 

 a vinegar quite superior to the ordinary type, having a finer 

 flavor and better keeping properties. Such a method of pre- 

 paring comparatively pure cultures is useful and quite fre- 

 quently used. 



Whether strictly pure cultures will ever be used in vinegar- 

 making cannot be predicted. If the product of any single fac- 

 tory were greater and compared with the amount of beer in a 

 brewery, it is certain that pure cultures would have been long 

 since adopted. The small amount of the product has rendered 

 questionable the wisdom of the expense and labor of preparing 

 and preserving pure cultures. 



Of course the farmer who simply lays aside his few barrels 

 of cider, or other alcoholic solution, to allow it to be con- 

 verted into vinegar, will not be troubled or especially inter- 

 ested in the matter of pure cultures. A little loss is nothing 

 to him, and the preparing and preserving of pure cultures an 

 impossibility. He feels tolerably confident that the cider 



