THE SACCHARINE SORGHUMS 387 



When grown for silage, the sweet sorghums should 

 be cut when the seeds are going out of the soft dough stage. 

 If the seeds are fully ripe many of them will pass through 

 the animal undigested. Sorghum for hay should be har- 

 vested when fully headed. 



When the crop is utilized for sirup, the leaves are usu- 

 ally stripped while the plants are standing. Whatever 

 the method followed it is important that the canes be 

 stripped before pressing; otherwise the yield of juice is 

 decreased and the percentage of impurities in the juice 

 is increased. The crop is cut by hand or with a corn 

 harvester. If the weather is warm the cut cane should be 

 pressed within one or two days after cutting to prevent 

 the stalks from fermenting. Frosted sorghum should be 

 cut at once and put in large shocks. This should be done 

 without stripping or topping the plants if the shocks are 

 to stand for several days. 



481. Manufacturing the sirup. — This process com- 

 prises three important steps: (1) The extraction of the 

 juice; (2) clarification of the juice, and (3) evaporation 

 of the juice. 



The juice is extracted by running the canes through 

 heavy roller mills run by horse power or by gasoline or 

 steam engines. From 30 to 60 per cent of the juice is ex- 

 tracted, the amount depending on the type of mill used. 

 The three-roller type ordinarily in use extracts about 60 

 per cent of the juice from the stalks. 



The raw juice contains from 20 to 30 per cent of impuri- 

 ties that are removed by clarification. The means of 

 accomplishing this are as follows: (1) Allowing the juice 

 to stand for some time to permit the impurities to settle 

 to the bottom. The juice is carefully drawn off leaving 

 the sedinient behind. (2) Heating the juice to coagulate 



