PURE YEAST CULTURE. 259 



that wine yeast is not a single species, but that it consists 

 of several varieties and species. 



After my system of pure culture had become recognised 

 in the brewing world, attention was directed to the fermenta- 

 tion of wine. Up to that time the costly must, as stated 

 above, had everywhere been left to a chance fermentation. 



The first to submit this question to a scientific treatment 

 was a Frenchman, Louis Marx (' Moniteur scientifique,' Paris, 

 1888). By means of my methods for the preparation of 

 pure cultures and the analysis of yeast, he proved that 

 several species occur in every wine yeast, that these often 

 present a similar appearance under the microscope, but 

 differ in other respects, and likewise exhibit a different 

 activity in the must. As in the Saccharomycetes investi- 

 gated by myself, it was found that also in the case of these 

 wine yeasts the development of the spores afforded useful 

 characteristics. Considerable practical importance attaches 

 to the experiments made by Marx with several of the species 

 which he isolated. Different portions of the same must were 

 inoculated with different species, and it was found that these 

 yielded wines differing in bouquet and taste. He, therefore, 

 expressed the opinion that, by employing a pure culture of 

 a certain selected species of yeast, it would be possible to 

 obtain a better wine than otherwise, even though the must 

 is inferior. This is essentially the same result as that ob- 

 tained in the brewing industry in 1882-84 by my experi- 

 ments. Marx described a method for the cultivation of large 

 quantities of pure yeast, by means of which a satisfactory 

 fermentation of the must could be secured in a convenient 

 manner. 



At about the same time another Frenchman, Rommier, 

 gave an account of some experiments on wine fermentation 

 in the ' Comptes rendus ' of the Paris Academy. He did 

 not, however, work with pure cultures, but he either took 

 his yeast in the impure state in which it occurred in the 



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