292 The Philippine Journal of Science 



yeast can be obtained from the Bureau of Science, and at the 

 same time instruction can be procured for keeping this com- 

 paratively free from infection. Clean yeast can be obtained by 

 inoculating a small quantity of sterilized 10 per cent molasses 

 wort by means of a sterile platinum wire or by the addition of 

 a few drops of stock yeast. When this is fermenting strongly, 

 it should be added to a larger volume of sterile molasses solution 

 (12 brix), preserving the proportion of 1 to 100 (or 150), and 

 the operation can be repeated with this volume until the content 

 of yeast is sufficient to inoculate the vat, which is ready to be 

 fermented. If care is exercised in choosing ferment in which 

 the yeast is not badly contaminated, the new vats can be in- 

 oculated by the addition of stock solution from vats in active 

 fermentation. By beginning with a 10 per cent solution of 

 molasses and making each successive solution slightly more con- 

 centrated until a brix of 16.5 is attained, the ability of the yeast 

 to ferment in more highly concentrated solutions is strengthened. 

 In other words, the principles embodied in the Molhant process 

 are being put in operation. The point of maximum alcohol 

 content should be determined by frequent determinations of the 

 alcohol present in the fermenting solution. When this point is 

 reached, the ferment should be distilled without unnecessary 

 delay. The ebullioscope is used by some concerns for this deter- 

 mination, but its use is unsatisfactory and cannot be relied upon. 

 The manufacturers specifically say it is for use in determining 

 the alcohol content of dilute alcohol solutions, dry wines, etc. 

 Where sugar or other solid is present in solution, the results 

 obtained by it are unreliable; consequently the alcohol content 

 of fermenting molasses cannot be measured by this instrument. 

 The temperature of the ferment should be kept between 28° 

 and 30° C. by suitable cooling coils. 



SUMMARY 



Some statistics of the alcohol industry in the Philippine Islands 

 and abroad are given. 



The data of a number of experiments with fermenting molas- 

 ses are recorded. These show the influence of various salts on 

 the rate of fermentation, the yield of alcohol, and the virility 

 of the yeast. They include several trial experiments on a large 

 scale with and without temperature control. 



Certain recommendations are made for the improvement of 

 the present methods of fermenting molasses. 



