MISCELLANEOUS ALCOHOLIC BEVERAGES AND PRODUCTS 633 



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 de- 

 stroys 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 con- 

 version requires from eight to twelve hours' boiling. The starch is first converted 

 into dextrins and then into glucose. If the boiling is too prolonged some of the glucose 

 may be lost by conversion into caramel. The amount of acid and the time of boil- 

 ing 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 acidity is reduced with calcium oxide or calcium 

 carbonate before fermentation. 



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

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

 oryza 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. The liquefaction of the starch is facilitated by slightly acidu- 

 lating the water with hydrochloric acid. The mixture is then cooled 

 to 38 and inoculated with a pure culture of the Mucor. A current of 

 filtered air is then passed through the mass for twenty-four hours, by 

 which time the mycelium has permeated the mass. The temperature 

 is then reduced to 33, pure yeast added and aeration continued for 

 twenty-four hours longer to promote the multiplication of the yeast. 

 Conversion of the starch and fermentation of the sugar then continue 



