

lt& 



CONTENTS 



CHAPTER I. 



PURE CULTURES OF SYSTEMATICALLY SELECTED 

 YEASTS IN THE FERMENTATION INDUSTRIES. 



PAGE 



1. WHEREIN THE NEW ADVANCE CONSISTS I 



Pitching yeast before and after introduction of the reform . . . . I 



Three periods of conflict .. .. .. .. .. .. 2 



2. MY METHODS OF PURE CULTIVATION 5 



My first pure cultures were prepared by dilution method in liquid 



medium .. .. .. .. .. .. .. .. 5 



Koch's plate culture in nutrient gelatine . . . . . . . . 7 



My single-cell culture in moist chamber .. .. .. .. 8 



Brefeld's methods ,, .. .. .. .. .. .. 9 



The methods of pure culture are only technical expedients .. .. 10 



3. THE CONTRIBUTIONS OF PREVIOUS INVESTIGATORS .. .. io 



The new science of the organisms of fermentation was founded by 



Cagniard Latour, Schwann, Turpin and Kutzing .. .. .. io 



Pasteur's ' Etudes sur la biere ' II 



The reasons why Pasteur's method for the purification of yeast by 



means of tartaric acid found no application in practice .. .. 12 



Different views concerning yeast .. .. .. .. .. 12 



4. THE PRACTICAL RESULTS WHICH HAVE BEEN ACHIEVED .. 14 



Jacobsen's objections .. .. .. .. .. .. .. 14 



The "diseases" produed by alcoholic ferments in the Tuborg and 



Old Carlsberg Breweries .. .. .. .. .. . 14 



My first experiments with pure cultivated yeast in Old Carlsberg .. 15 

 Are special secondary yeasts necessary to bring about the desired 



fermentation? .. .. .. .. .. .. .. .. 16 



Scientists who from the beginning have worked for my reform . . 17 



The advantages of the reform .. .. .. .. .. .. 18 



Misunderstandings and mistakes .. .. .. .. .. 19 



Reasons for advising against the employment of mixed yeasts . . 22 

 The question of abolishing the open coolers could only be considered 



after the yeast question had been solved . . . . . . . . 23 



