CHAPTER XXYI. 



FERMENTATION WITH SPECIAL REFERENCE TO THE 

 SUGAR HOUSE. 



This chapter treats principally of the fermentation of molasses and of the 

 manufacture of rum ; incidentally opportunity is taken to bring together some 

 part of the scattered articles dealing with the mycology of the sugar house. 



Yeast. By this term is loosely meant any organism which has the 

 property of fermenting sugars and producing mainly alcohol and carbon dioxide ; 

 in this sense organisms such as the Torulae, Monilia, and certain of the 

 Mucoraceae would be included, although these organisms are very distinct 

 from that mainly composing 'brewers' yeast,' which consists essentially of 

 SaccJiaromyces cerevisiae. Systematically production of alcohol is not an 

 essential character of the Saccharomyces although the greater number of species 

 here included do produce alcohol ; in addition some species ferment saccharose, 

 dextrose, maltose ; others dextrose and maltose only ; others lactose only. 



A complete list of all the known ' yeasts ' is given by Kohl 1 ; following 

 him they are divided into these groups : 



I. Yeasts proper or budding yeasts. Saccharomycetes. These are divided 

 into the following genera : 



I. Saccharomyces; 2. Hansenia ; 3. Torulaspora ; 4. Zygosaccharomyces ; 



5. Sacchar omy codes ; 6. Saccharomy copsis ; 7. PicTiia ; 8. Willia. 



II. Fission Yeasts, Schizosaccharomycetes. This includes one genus, 

 Schizosaccharomyces. 



III. Yeast like fungi. These are divided into the following genera : 

 1. Torula; 2. My coder ma ; 3. Monilia ; 4. Chalara ; 5. Oidium ; 



6. Dematium ; 7. Sachsia; 8. Endomyces ; 9. Monospora\ 10. Nematospora. 



In European and North American breweries and distilleries alcoholic 

 production is mainly produced by the species S. cerevisiae; a closely allied 

 yeast 8. vordermanii is responsible for most of the alcohol produced in 

 tropical countries from molasses ; in addition, fission yeasts have been observed 

 in the Antilles 2 , in Jamaica 3 , in Natal 4 , and in Peru 5 ; they are of great 

 importance in the production of rum, but have not received the extended study 

 that has been given to the budding yeasts. 



Yeasts of special Interest in Connection with Rum 

 Distilleries. The first detailed study of any yeast in connection with the 

 cane sugar industry is that due to Went and Geerligs 6 , who isolated from 

 Raggi or Java yeast a species which they named S. vordermanii ; this is a 

 typical budding yeast. 



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