a 
RR 
rere 
SUGAR-CANE SIRUP MANUFACTURE 59 
cessed, rather than canned directly, it should flow from the coolers 
into a ae tank. Sirup need not be cooled to atmospheric tem- 
perature before bemg discharged from the coolers mto the storage 
tanks; reduction in temperature to 120° F. 1s sufficient. 
The capacity of the coolers depends upon the capacity of the 
evaporators and the canning facilities. If the sirup is reheated for 
canning, the processing pans should be large enough to furnish hot 
uP at the rate required for canning. ‘The sirup, after being heated 
to the required temperature, should flow from the processing pan to 
the fillmg tank or directly to the fillmg machine. In small sirup 
houses, this equipment usually consists of a small tank and hand- 
operated valve for filling the cans; in larger canning plants, special 
machinery is employed (p. 61). 
CANNING TEMPERATURES 
The temperature to which cane sirup must be heated to prevent 
fermentation varies with the time during which an elevated tem- 
perature is maintamed. When a required minimum temperature is 
exceeded, a lower temperature is as effective as a higher temperature, 
provided the lower one is applied for a sufficiently longer time. 
For this reason the temperature required for the preservation of 
sirup varies with the volume in the cans. As a larger volume takes 
a longer time to cool, the temperature required for preservation. of 
sirup in large cans is lower than that essential in smaller cans. The 
canning temperatures shown in Table 17 are generally effective for 
cane sirup packed in cans of various sizes. 
‘“‘Hffective temperature’ means the temperature of the sirup in 
the can at the time it is closed; the processing temperature is usually 
about 10° higher. Although there is no objection to canning sirup 
at a temperature a few degrees higher than the temperatures given 
in Table 17, the cans should not be closed when the temperature of 
the sirup is lower than that recommended. Higher temperatures are 
not only unnecessary; they cause the sirup to darken and may pro- 
duce “‘buckling”’ of the cans, owing to the production of too high a 
vacuum on cooling. 
TaBLE 17.—Canning temperatures for cane sirup 
Effective 
Size of can tempera- 
ture 
2 Jo. 
INO ALO es pe toa re 160 
INO WO! Ssstte sae Woe ae 165 
NOE ZUG SSS ers Ss ae 177 
UNG ee Sek ee 177 
COOLING SIRUP AFTER CANNING 
If cans of hot cane sirup are stacked or placed in such a position that 
they cool very slowly, the sirup may andere “stack burning.” This 
has practically the same effect upon color and flavor as overheating. 
The sirup becomes red and acquires a sharp, burnt taste. Not 
infrequently “stack burning” causes the cans of sirup to swell or 
bulge at the ends, as if their contents had fermented. This trouble 
is easily avoided in a small sirup house, where the output is relatively 
small and the problem of storing the hot cans is not difficult, by simply 
