290 



The Philippine Journal of Science 



1917 



Table XXI. — Data on ferment, results of which are recorded in Table XXII. 



Liters. 



Water 12,600 



Molasses 2,500 



Total initial volume 15,100 



Total final volume 14,950 



Note. — Sulphuric acid, 2 grams per liter; ammonium sulphate, 

 brix, 16.2. 



i.4 grram per liter; initial 



Table XXII. 



-Results obtained by fermentation of molasses without inocu- 

 lation and without cooling coil. 



Fermen- 

 tation. 









Density. 



Alcohol. 



Temper- j Cell 

 ature. ' count. 



Alcohol, 



by 

 volume. 



Maxi- 

 mum 

 yield. 



Yield, 

 per cent 

 of theo- 

 retical. 



Hours. 

 16 

 40 

 64 

 88 

 112 



°c. i 



31 j 1.3 

 38 j 78.7 













' 







6.16 1 6.8 

 6.24 6.4 







84 

 32 



47.9 

 41.0 



6.24 



70.1 











The yield recorded in Table XXII is only 77.9 per cent of what 

 the yield was in Table XVIII. This excess of Table XVIII over 

 Table XXII can be ascribed to the one sterilization at the begin- 

 ning, to the use of pure yeast cultures, and to the reduced tem- 

 perature during fermentation. The high temperature in the 

 latter case is conducive to bacterial growth, greater evaporation 

 of the alcohol, increase of acidity, and incomplete fermentation, 

 because of the decreased production of enzymes from the yeast. 

 The attenuation, which is an approximate measure of the degree 

 of alcoholic fermentation, was not as complete in Table XXII, 

 where it proceeded from 16.2 to 6.4, as it was in Table XVIII, 

 where it went from 16.5 to 3.8. 



As has been already mentioned, many of the distilleries of 

 the Philippine Islands ferment nipa juice either alone or mixed 

 with diluted molasses. In order that the efficiency of this method 

 might be determined, the experiment tabulated in Table XXIII 

 was carried out. 



Table XXIII. — Constitution of ferment, results of which are recorded in 

 Table XXIV. 



Liters. 



Water 10,000 



Tuba 8,700 



Molasses 2,700 



Total initial volume 21,400 



Total final volume 21,000 



Note.— Initial acidity, 8.5 cubic centimeters 0.1 N alkali in 10 cubic centimeters of ferment ; 

 Initial brix, 12.6. 



