UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 921 
~|j2^* Contribution from the Bureau of Chemistry 
SZ& < &5<~ CARL L. ALSBERG, Chief 
Washington, D. C. 
November 9, 1920 
SUGAR-CANE JUICE CLARIFICATION FOR SIRUP 
MANUFACTURE. 
By J. K. Dale and C. S. Hudson. 
CONTENTS. 
Page. 
Two methods in general use 1 
Disadvantages 2 
New method of clarification 2 
Outline of process 2 
Industrial development 2 
Experimental plant 3 
Operation 3 
Experiments conducted 3 
Discussion of results 6 
Economic considerations 7 
Page. 
Vacuum evaporation in making cane 
sirup 12 
Use of vegetable decolorizing car- 
bons in connection with infusorial 
earth clarification 14 
Infusorial earth clarification for 
sugar manufacture 14 
Summary 15 
TWO METHODS IN GENERAL USE. 
Two methods of clarifying sugar-cane juice in the manufacture 
of cane sirup have been developed and are now in general use in 
this country. One process, following closely the method of clarifica- 
tion used in the manufacture of direct-consumption sugars and fa- 
vored principally in the sugar-cane-producing region of southern 
Louisiana, where sugar also is manufactured, consists essentially in 
treating the juice, freshly expressed, with fumes of burning sulphur 
(S0 2 ) and milk of lime. The juice is heated and the coagulated 
impurities allowed to settle or removed by settling and skimming, 
after which the clear liquor is evaporated to sirup in open evapo- 
rators or vacuum pans or by a combination of open and vacuum 
evaporation. 
The other and. simpler process, used in all cane-sirup-producing 
regions outside of Louisiana and a small section of Texas, consists 
in heating the juice and skimming off the scums and coagulated 
material which rise as the juice becomes hot, forming a thick blanket 
on the surface. As a rule no chemicals are used in this process, 
though some sirup makers add a small amount of milk of lime to 
u make the skimmings rise better." This method requires only the 
smallest, crudest sort of equipment, but when careful attention is 
given produces an excellent sirup. 
13702°— 20 
