98 BULLETIN 1370, U. S. DEPARTMENT OF AGRICULTURE 
tion is most effective at high temperatures. Provided deterioration in — 
color and flavor does not result from the prolonged retention of heat, | 
wooden troughs or insulated tanks may be used to keep the sirup hot 
and thus facilitate sedimentation. If the color darkens appreciably — 
when the sirup is kept hot, however, it is considered better practice to _ 
cool it sufficiently to prevent this deterioration in quality before 
running it to the settling tanks, and then permit it to sediment for a 
longer period. : 
The importance of cleanliness in making sirup can not be too | 
strongly stressed. As one object of clarification. and evaporation is — 
the removal of suspended material and the sterilization of the sirup | 
by heat, it 1s obviously unreasonable to permit dirt of any kind, which 
is likely to cause fermentation, to contaminate the sirup after it has 
been made. In addition to keeping the evaporator and tanks free 
from sediment and scale, it is well to dispose of the skimmings in such 
a way that they do not become sour, thus creating an unsanitary con- 
dition around the mill. The sirup plant should be supplied with | 
plenty of water, so that all the equipment may be washed as often as © 
necessary. All equipment that has stood idle for several days should 
be thoroughly washed with strong limewater, which neutralizes acids 
and to a certain extent prevents fermentation. If lime is used, how- 
ever, all equipment should be carefully washed again before resuming 
greeny as the addition of lime to juice or sirup produces a dark 
color. 
CLARIFICATION BY SULPHUR DIOXIDE AND LIME 
By C. E. Coats and W. G. Tageart, Louisiana State University and Louisiana 
Sugar Experiment Station 
The process of clarifying cane juice by the use of sulphur dioxide 
and lime is practiced in many factories where sirup making is con- 
ducted on alarge scale. This method has long been in use in most of 
the larger Louisiana sirup factories, and is therefore commonly called 
the Louisiana process of clarification. As the sulphur dioxide bleaches 
some of the pigments in the juice, sirup made by this process has a 
lighter color than that ordinarily produced by the boiling and skim- 
ming method. The use of sulphur dioxide and lime also gives the juice © 
a more complete clarification than is obtained by simply boiling and 
skimming. 
A preliminary removal of suspended material from the juice as it 
leaves the mill (p. 15) is the first step in this process. In the larger 
factories the separation of suspended matter, such as particles of 
bagasse and adhering soil, is usually accomplished by straining the | 
Juice, as it leaves the mill, through fine-mesh bronze or copper sieves | 
or through cloth. In order to prevent loss of juice, the material 
removed from the juice by straining should be returned to the 
bagasse at some point on the carrier before it reaches the iast mill. | 
Straiming the juice is of great importance, not only on account of the } 
danger of clogging pipe lines and pumps by the suspended material, | 
but also because the presence of sediment in the juice tends to impart — 
undesirable properties to the sirup. . : | 
Although it is the general custom to run the strained juice to the | 
sulphuring apparatus without further treatment, the small particles | 
that pass through the screen are sometimes removed by filtration or | 
_ sedimentation. At this stage of the process sedimentation of the | 
juice is inexpensive and is always considered good practice. qj 
