﻿6 BULLETIN 1129, U. S. DEPARTMENT OF AGRICULTURE. 



Table 9. — f^orr.parison of temperature, time of steeping, and time of germination of 



grain sorghums. 









Average 









daily 







Time of 



tempera- 



Malt 



steeping. 



germina- 

 tion. 



ture 



during 

 germina- 









tion. 





Hours. 



Days. 



°C. 





30 

 30 



22 



14 



8 

 10 



17 



Milo 



20 





20 







The difference in the time of steeping shown in Table 9 is due to 

 the capacity of the various grains to absorb water, this capacity 

 being governed principally by the hardness and compactness of the 

 grain. The interior starchy portion of the kafir and milo kernels is 

 harder and more glassy than that of the feterita, and consequently 

 requires a longer time for the complete absorption of water. The 

 time of germination varies in each case, but is governed to a large 

 extent by the temperature. The grain required a shorter time for 

 germination in cases where the temperature was higher. 



DIASTATIC POWER OF MALTED GRAIN SORGHUMS. 



After the malting was completed the finished malt was analyzed 

 by the following methods : 



Preparation of sample. — After the malt had been thoroughly mixed 

 and a uniform sample taken, it was ground to pass a 20-mesh sieve. 



Moisture. — Two grams of the ground malt was accurately weighed 

 in a covered weighing dish and dried at 60° C. in a vacuum to con- 

 stant weight. 



Diastatic power (3) . — Twenty-five grams of ground malt was 

 extracted with 500 cubic centimeters of distilled water (free from 

 ammonia, nitrates, etc.) for 3 hours at 21° C. and filtered. The first 

 100 cubic centimeters of the filtrate was rejected. Then 100 cubic 

 centimeters of a 2 per cent starch solution (soluble starch prepared 

 according to Lintner) was treated with 1 cubic centimeter of the 

 malt extract of diastase solution for 1 hour at 21° C, 50 cubic centi- 

 meters of Fehling solution was added, and the whole was heated 

 rapidly to 98° C. It was next placed in a boiling water bath for seven 

 minutes, and, without being diluted, the cuprous oxid was filtered 

 immediately, dried, and weighed. The weight of cuprous oxid was 



Cu 

 calculated to copper by the following factor: /-, i^ = 0.8882. The 



weight of copper found minus the weight of copper reduced by 100 

 cubic centimeters of the 2 per cent starch solution (determined by a 

 blank on this amount carried through the regular procedure) was 

 divided by 0.441 (gram of copper in 50 cubic centimeters of Fehling 

 solution), and this result, multiplied by 100, gave the Lintner value. 



