b STUDIES ON FERMENTATION. 



the beer acquires a sour taste and smell that render it detestable. 

 AVe have met with this ferment existing in beer, unaccompanied 

 by other ferments, and have been convinced of its fatal effects. 



No. 6 represents one of the deposits belonging to wort. This 

 must not be confounded with the deposits of diseased ferments. 

 The latter are alwa^'s visibly organized, whilst the former is shape- 

 less, although it would not always be easy to decide between the 

 two characters, if several samples of both descriptions were not 

 present. This shapeless deposit interferes with wort during its 

 cooling. It is generally absent from beer, because it remains in 

 the backs, or on the coolers ; or it may get entangled in the 

 yeast during fermentation and disappear with it. 



Among the shapeless granulations of No. 6 may be discerned 

 little spheres of different sizes and perfect regularity. These are 

 balls of resinous and colouring matter that are frequently found 

 in old beer, at the bottom of bottles or casks ; sometimes they 

 occur in wort preserved after Appert's method. They resemble 

 organized products, but are nothing of the kind. We have 

 remarked before, in " Studies on Wine," that the colouring 

 matter of wine would settle, in course of time, in that form. 



It is evident that the diflFerent ferments delineated in Plate I. 

 are worthy of thorough study, in consequence of the fermenta- 

 tions to which they may give rise. Care must be taken to isolate 

 the action of each of them in fermentations which we may call 

 pure — a condition of some difficulty, but one that maybe carried 

 out by an adoption of the methods explained in this work. 



All these diseased ferments have a common origin. Their 

 germs, infinitesimal and hardly perceptible as they are, even 

 with the aid of the microscope, form a part of the dust conveyed 

 through the air. This dust the air is continually taking from 

 or depositing upon all objects in nature, so that the dust that 

 clings to the ingredients from which our beer is manufactured, 

 may teem with the germs of diseased ferments. 



During the process of fermentation, the occult power of 

 diseased ferments, although it may escape the observation of the 

 brewer, is manifested in a high degree. 



