sugar Production

Though sugar cane has been cultivated and refined for thousands of years, sugar was not an accessible commodity until the 18th century when production expanded with Caribbean colonization. At the time it was crudely refined and primarily available in the European countries which had sugar producing colonies. Sugar became widely available once the refining process was improved by technology and processes became industrialized. Innovations in processing sugar have created a refining process that is very efficient at extracting crystallized sugar from cane juice. 

Over the same time, sugar cane has been hybridized extensively to create a crop that will have high yields of sugar and also be resistant to disease and pests. Sugar cane is susceptible to a variety of diseases and pests. Hybridization creates varietals that have stronger resistance to specific diseases and each growing region has selected hybrids that perform best considering the soil, climate, pests, and diseases in an area. While sugar cane is a perennial, most growers treat it as an annual, replanting every year. Fully harvesting is a more efficient process and new growth will return higher crop yields than regrowth. If a farm chooses to treat sugar cane as a perennial they harvest and leave the rootstock to regrow for the next season. Up to ten harvests can be had with this method, but each regrowth returns increasingly lower yields than new growth. Since annual harvesting and regrowth require the same nutrition and amount of care, replanting every season is a practical choice to maximize return.

At harvest, time is a critical factor in achieving a quality product. Milling has to occur within 24 hours or the cane and its juice will spoil. With a high concentration of simple sugars, microbial fermentation happens very quickly and will degrade the quality of the juice rendering it sour and unusable. Harvests are usually performed quickly with equipment that harvests, strips away the chaff that accumulates on the stalks, and cuts the stalks into small sections that are then deposited into a wagon to be taken to a sugar mill which will be located nearby. 

The stalk cuttings are sent straight into the mill from the field where they are crushed, rinsed, and pressed to extract sugar from the fibers. This juice is then clarified to remove any impurities such as dirt, chaff, or fibers that were not filtered out during crushing. After clarification the juice is sent to evaporators where water is removed by boiling the juice at low temperatures. During boiling sucrose concentrates and crystallizes and remains suspended in molasses. The resulting mix of crystallized sugar and molasses is sent to a centrifuge and spun to separate molasses from the crystallized sugar. 

At this stage raw sugar has been made. To produce refined sugar that people are familiar with, the raw sugar is sent to a refinery. Refineries are different from sugar mills in that they are not processing any raw ingredients and the sugar made in a refinery is food grade. The raw sugar is first dissolved into a syrup and clarified to remove any impurities in the raw sugar. After clarification the syrup passes through a filtration process to remove color. The syrup is then recrystallized and sent through a centrifuge to separate the crystals from the remaining syrup. After drying, the refined is packaged for sale or will be used to make other products like brown sugar or sugar in the raw. The molasses remaining from the milling process will be used for baking, livestock feed, or for rum production.