74 MICRO-ORGANISMS AND FERMENTATION. 



He impregnated a series of Freudenreich flasks, contain- 

 ing sterile, clear wort or beer, with different volumes of 

 water, and noted the day on which a change in the contents 

 of each flask (cloudiness, formation of a skin, fermentation) 

 became visible. The more rapidly decomposition sets in, and 

 the smaller the necessary quantity of water, the more noxious 

 the character of the water. By giving numerical expressions 

 to the time (setting in of decomposition), and to the quantity 

 of water, the figure specifying the destructive capacity will be 

 a product of these two factors. Beer, however, possesses a 

 greater power of resistance than wort, so that in cultivations 

 in the former, the coefficient must be correspondingly reduced. 



Lindner added sterile wort to the water, and distributed 

 the mixture by means of a pipette drop by drop into a series 

 of Petri propagating dishes. The growths which developed 

 were counted, and from this the number of germs per c.c. was 

 calculated. 



The result of many years' experimenting in the author's 

 laboratory have led to conclusions which are at variance with 

 those stated above. The first growths to appear in the wort 

 flasks are almost always putrefactive bacteria, water bacteria, 

 and the like ; just those forms which are of little interest in 

 brewing operations, because they do not develop in the finished 

 product. The special technical character of the analysis is 

 lost if the time taken for the appearance of the bacteria is 

 made the basis on which the character of the water is judged. 

 Moreover, in forming an opinion as to the character of water 

 from the technical standpoint, it is not essential that the 

 quantity of wort-bacteria in a given volume should be esti- 

 mated. On the contrary, when growth in the flasks has been 

 allowed to continue for some time, it has been shown that in 

 more advanced stages species appear which are known as 

 disease germs, as, for instance, the wild yeast. Thus it is 

 the last stage of the development in the flasks which is of real 

 importance. In making the investigation both the wort and 

 the beer flasks should be infected with small quantities of 

 water. In some flasks the water is added in an undiluted 

 condition ; in others it is more or less diluted. Samples are 

 taken from time to time for microscopical, and eventually, 



