304 GRAPE CULTURE AND 



suits of some of these throw so much light upon the causes 

 of "difficult fermentations" that it seems proper to give 

 publicity to them in advance of any detailed report on the 

 whole series. 



Equal charges of 200 pounds each were fermented in 50- 

 gallon tanks, save that in the hot fermentations 25 pounds 

 more were used, in order that the rise of temperature might 

 be favored by greater mass. In the hot chamber a tempera- 

 ture of between 85 and 90 was maintained ; while in the 

 fermenting-room in which the other charges were being treated, 

 the temperature was kept as nearly as possible at 75. The 

 grape employed was a fine lot of Carignane, courteously do- 

 nated for the purpose by A. J. Salazar, Jr., of Mission San 

 Jose. The must showed 25.75 per cent, by spindle and 53 

 per cent, or a little over h\e pro niille, of acid. 



Of the tanks in the fermenting-room filled with mash at 

 63, three, treated by usual methods, went practically dry 

 and were sent to press on the seventh day ; the first to finish 

 being the one with "floating cover and twice-daily stirring," 

 the method adopted in the laboratory for general purposes. 

 The highest temperature reached by any of these was 95. 



On that day (7th) the two tanks in the hot chamber, which 

 had in setting been warmed up to 86 U and at first fermented 

 most violently, and in forty-three hours attained a maximum 

 temperature of 106, had come down to very slow movement; 

 the actual solid contents were found to be a little over 12 per 

 cent.- It being obvious that they would not "go through" 

 under existing conditions, the two charges were divided into 

 four parts, of which one was left in the hot chamber and 

 treated as before, in order to observe the outcome. The 

 others served for experiments to test the best mode of reviv- 

 ing the fermentation in the lower temperature of the ferment- 

 ing room. 



One portion received 1^/2 per cent, of pomace, freshly 



