July 2, 1920.] Agricultural Gazette of N.S.W. 479 



Sorghum as a Possible Source of 

 Industrial AlcohoL 



A. A. RAMSAY, Principal Assistant Chemist. 



The following varieties of sorghum grown at Hawkesbury Agricultural 

 College, Richmond, were lately examined as to their suitability for the pro- 

 duction of industrial alcohol : — (1) Early Amber Cane, (2) No. 47, (3) No. 54, 

 (4) No. 51, (5) No. 49, (6) Sorghum saccharatum, (7) Planter's Friend, (8) 

 No. 34, (9) Saccaline. Nos. 34 to 54 are selected varieties of Planter's 

 Friend. All the varieties were examined at the same relative state of 

 ripeness. 



A hundredweight of the sorghum was divested of leaves, the top portion 

 carrying the seed was removed, and the remaining canes were crushed in an 

 experimental mill (power driven) which was kindly loaned for this work by 

 the Colonial Sugar Refining Company, Ltd. The mill, a two-roller one, was 

 set very close (rpr of an inch), so close, in fact, that the stalks would just pass 

 through without pulling the mill up. The expressed juice was collected and 

 examined. 



The results obtained are set forth in Table I. It will be noted that the 

 yield of sorghum in the field ranged from 5*5 to 17 "6 tons per acre, and 

 the average yield of all varieties was 14 tons per acre. The " tops " or heads 

 of the sorghum varied from 8"9 to 26 8 per cent, of the total weight of 

 gro\ving sorghum, the mean being 13"9 per cent., and the leaves varied 

 from 107 to 20"7 per cent., the mean being 14*3 per cent. The percentage 

 of clean stalks varied fi'om 60*7 to 80*4, the mean being 71 '9 percent. 



The yield of juice expressed by single crushing also showed wide variations, 

 viz., from 20 per cent, to 36 per cent., the mean yield being 27*7 per cent, of the 

 weight of the clean stalks crushed. The yield of juice will be dealt with later. 



The sucrose content of the juice expressed ranged from 4 "7 to 14 8 per 

 cent., with an average of 9'99 per cent. The fruit sugar content ranged from 

 2"1 to 4" 5 per cent., the average being 3 "08 per cent. 



From the composition of the juice as stated above, the theoretical yield of 

 alcohol has been calculated, using Pasteur's figures, and the yield is further 

 expressed as imperial gallons of 95 per cent, alcohol. Pasteur's figures have 

 not been realised in actual distillery practice. These figures were obtained 

 from pure sugar solutions and nutrient media, therefore the yield of alcohol 

 in practice might be appreciably reduced. 



The figures obtained show that the yield of 95 per cent, alcohol ranges 

 from 6"8 to 113 gallons per acre, with an average of 52-7 gallons, or ex- 

 pressed in terms of 1 ton clean canes, the yield ranged from 2-03 to 7 '9 9 

 gallons with a mean of 4'85 gallons. 



