MICROBIOLOGY OF ALCOHOL AND ALCOHOLIC PRODUCTS. 445 



Cane molasses which contain from 50 to 60 per cent of fermentable sugar are diluted 

 with water or vinasses to 15 to 18 Bal. and partially neutralized with lime when the 

 acidity is excessive. 



One of the principal sources of industrial alcohol is the sugar beet. This alcohol is 

 also used for the adulteration or imitation of potable spirits. 



It may be made by the direct fermentation of the beet juice, extracted by grinding 

 and pressing, by methodical maceration or by diffusion. Sulphuric acid is added 

 during extraction. This facilitates the extraction by setting free organic acids, and 

 represses the growth of injurious microorganisms. The amount used should be such 

 that a minute quantity of sulphuric acid remains free. 



Most beet alcohol is made from the coarser molasses of the sugar factories. The 

 molasses are diluted to 20 to 30 Bal. with water, further diluted and heated with 

 steam and acidified with sulphuric acid. The sulphuric acid neutralizes the lime which 

 has been used in the manufacture of the sugar, sets free the volatile acids and breaks up 

 the nitrites producing nitrogen peroxide. The liquid is then boiled for about one 

 quarter of an hour to drive off the volatile acids and the oxides of nitrogen which would 

 prevent yeast fermentation. The liquid after cooling is then fermented with yeast. 



Starchy Raw Materials. In the preparation of a fermentable solu- 

 tion from starchy materials three methods for the conversion of the starch 

 into sugar may be used, depending respectively on the action of malt, 

 dilute mineral acids, and certain molds. 



The malt used in saccharification may be made in a manner similar to that 

 described for brewing, from barley, oats, rye or maize. As the object in this case is to 

 cause complete conversion of the starch with as little malt as possible, the malt should 

 have the maximum diastatic power. For this reason, germination should be carried 

 further than for brewing and the malt used green. Drying the malt destroys half its 

 diastase. 



The conversion may also be accomplished by boiling one part of grain in four parts 

 of water with hydrochloric or sulphuric acid. With the former acid, 10 per cent of the 

 weight of the grain is used and 5 per cent with the latter. The conversion requires 

 from eight to twelve hours' boiling. The starch is first converted into dextrins and then 

 to glucose. If the boiling is too prolonged some of the glucose may be lost by conver- 

 sion into caramel. The amount of acid and the time of boiling may be much reduced 

 by operating under 2 to 3 kg. pressure. In this case 200 liters of water are heated with 

 100 kg. of grain and 4 kg. of acid. Conversion occurs in from 40 to 60 minutes. 



The power of certain molds, especially mucors, to convert starch into 

 sugar has been utilized. Mucor rottxii found in Chinese yeast, Mucor 

 oryzcB in Ragi, and related forms have been used for this purpose. This 

 is known as the Amylo Process. The grain is first soaked for a few hours, 

 then heated with twice its weight of water under a pressure of three and 

 a half to four atmospheres until soft and the starch rendered soluble. 



