YEASTS OF SAAZ AND FROHBERG 233 



WILL'S YEASTS 



Variety 2, H. Will. 1 Large round or oval cells. On gelatin the 

 colonies are spherical or lenticular. Ascospores develop easily and 

 abundantly. The temperature limits for the formation of ascospores 

 on plates are 31 and 11 C., the optimum being near 25 or 26 C. 

 The temperature limits for scum formation on beer wort are from 28 

 -31 C. to 8-11 C. This variety is a bottom yeast which is an ac- 

 tive fermenter. 



Variety 6, H. Will. The cells of this variety are oval and some- 

 times curled. The colonies are spherical or lenticular on gelatin. 

 Ascospores are formed easily and abundantly. The temperature 

 limits for ascospore formation on plaster blocks are 31 and 11 C. The 

 optimum is 28 C. The temperature limits for scum formation are 

 25-31 and 7-10. This species is a moderate fermenter and a bottom 

 yeast. 



Variety 7, H. Will. The cells 'are round with giant cells mixed in. 

 At 'the end of fermentation, chains may be seen composed of small 

 cells in the budding stage. The colonies on gelatin are at first ir- 

 regular with a winding embattled edge. Ascospores are formed with 

 difficulty. The temperature limits for the formation of ascospores 

 on plaster blocks are 30 and 13. The optimum is around 25 or 26 C. 

 The limits of temperature for the formation of scum on beer wort 

 are 20-28 and 4-7 C. This variety is a bottom yeast with feeble 

 fermenting ability. 



Variety 93, H. Will. The cells are round or oval and the gelatin 

 colonies spherical or lenticular. The temperature limits for the for- 

 mation of ascospores on plaster blocks are 30 and 10 C. The opti- 

 mum is 28 C. The temperature limits for scum formation on beer 

 wort are 30-31 and 4-7 C. The scum contains numerous durable 

 cells. This variety is a very active bottom yeast. 



YEASTS OF SAAZ AND FROHBERG 



Although insufficiently known from the standpoint of morphology, 

 we should not pass these yeasts in silence for they play an impor- 

 tant role in the industrial alcoholic fermentations. One was found in 

 a Bohemian brewery (Saaz), the other in a brewery at Frohberg 

 having been isolated by Lindner. 2 Since that time they have been 



1 Will, H. Vergleichende Untersuchungen an vier untergarigen Arten von 

 Bierhefe. Zeitschr. f. d. ges. Brauw. 18, 1896. 



2 Lindner, P. Mikroskopische Betriebskontrolle in den Garungswerben. 

 Paul Parey, Berlin, 6th Edition, 1909. 



