Sugar cane for syrup is grown over a somewhat wider area in the United States than sugar cane for sugar. The area extends from eastern Texas east to South Carolina. Since most production is in areas with a shorter growing season than the sugar producing areas, early maturing varieties are essential. Most of the cane grown for syrup is in small acreages and the syrup is manufactured on a small scale, although there are a few sizable factories.
For best yield and quality of syrup, harvest should be delayed until the cane is mature, but before it is killed by freezing. Leaves are stripped from the standing cane either by beating off with a cane stripper, cutting, off or pulling off by hand. Stems are topped and cut near ground level. Delay of up to 30 days between cutting and making the syrup does not impair either yield or quality of the syrup, provided the cane does not freeze.
In general, mills with three horizontal rollers are used to extract the juice. Larger mills may use rollers under hydraulic pressure. One hundred pounds of cane should yield 50 to 60 pounds of juice. Open-type, continuous flow evaporators are generally used to concentrate the juice. The cold juice enters the lower end of the evaporator which is heated by fire beneath or, in larger installations, by steam coils. When the juice is heated, proteins and some other non-sugar constituents coagulate, float on the surface, and are skimmed off at the upper end.
In manufactured apparatus a final finishing or evaporating vat may be used. Proper density of the finished product is determined by using a hydrometer (35-360 Baume), or determining the boiling point with a thermometer (226-228 F.). The finished syrup is then filtered and placed in containers while hot. Production of cane syrup has fluctuated widely reaching more than 28 million gallons in 1945 when sugar was scarce because of World War II. Production in 1966 and 1967 averaged 2.2 million gallons annually. All is used as food. With good varieties and good agronomic practices an acre of cane should produce from 500 to 600 gallons of finished syrup. Average yields, however, are only about half this amount.