330 COBN CROPS 



water. The amount of sirup produced from a ton of 

 canes is therefore very variable. 



In general, a ton of canes will give 700 to 1200 pounds 

 of juice, which in turn will yield 10 to 30 gallons of sirup, 

 according to quality. 



272. The manufacture of sorghum sirup consists of three 

 steps: (1) extraction of juice; (2) clarification of the raw 

 juice ; (3) evaporation of juice. 



The extraction is done with heavy roller presses of either 

 the two-roller or three-roller type. The juice is then 

 run into settling tanks, where impurities in suspension 

 are allowed to settle out. 



The clarification is accomplished in some cases by 

 merely allowing the raw juice to settle for some time. 

 Settling is hastened by heating. Sometimes fine yellow 

 clay is added, which aids in settling. When the juice is 

 somewhat acid, lime also is added to the heated juice. 

 After clarification the clear juice is drawn off to be con- 

 centrated. 



Concentration takes place in large, shallow pans, where 

 the juice is kept boiling by a well-regulated fire. Ordi- 

 narily the pan is divided into compartments, the boiling 

 juice flowing slowly in a thin layer from one end to the 

 other. By the time the outflow is reached, the juice 

 should be concentrated into sirup. In very small plants 

 the juice is merely boiled down in kettles. 



