As it takes eighteen months for a crop to mature in Hawaii, it will readily be seen that the plantation area must be at least double that used for any one crop. While one crop is being harvested, another crop is in the ground growing. As soon as the cane is cut, the lands are immediately prepared for replanting or ratooning, as the case may be. During certain periods each year, usually in June and July, a visitor on an Hawaiian plantation can see one crop growing, one being harvested and one being planted.
From the foregoing it will be seen that the harvesting begins in December and ends in July or August. The planting begins from March to June and usually ends in September, according to plantation conditions and whether or not the land is irrigated.
THE MANUFACTURE OF RAW SUGAR
The details of the manufacture of raw sugar from cane and of sugar from beet roots differ, but there are several processes common to both. The operations necessary for making raw cane sugar are as follows:
- 1. The extraction of the juice.
- 2. The purification of the juice.
- 3. The evaporation of the juice to syrup point.
- 4. The concentration and crystallization of the syrup.
- 5. The preparation of the crystals or grains for the market by separating them from the molasses.
Every mill has an extensive laboratory where skilled chemists are constantly engaged in sampling and analyzing cane, raw juices, syrups, sugars and molasses. In fact the chemical work is a most important feature in the raw-sugar house, beet-sugar factory or refinery. The superintendent should be an expert chemist, as the proper recovery of the sugar from the cane and beet juices is wholly dependent upon the technical control of manufacturing processes.
EXTRACTION
After passing the scales, the cars containing the cane are switched alongside the carrier which feeds the cane into the mills. Before the cane is unloaded, however, samples are taken from each car and sent to the laboratory, where they are carefully analyzed. The amount of sugar present is ascertained, as well as the quantity and quality of the juice in the cane. It is, however, impossible to get a fair average sample of the cane in this way, and therefore the efficiency of the mill work is determined on the basis of an analysis of the juice and the fiber after it has passed through the crushers.
