How Sugar Works

Table sugar is extracted from the roots of sugar beets and the stalks of sugarcane. It's a big business: The world produces more than 78 million tons (71 metric tons) of sugarcane annually [source: The Sugar Bureau]. It can take up to 18 months for new cane stalks to be ready for harvest, and harvesting is often done now by machines on large plantations. Processing and packaging often occurs very close to the harvest location to prevent the harvested cane or beets from rotting.

The extraction process for sugar beets generally runs from September to February [source: The Sugar Bureau]. A beet is 17 percent sugar, so the task is to draw out this sugar from the beet, which is a root. The beets are sliced and placed in hot water, which produces a sugary juice. This juice then goes through several filtration, purification and concentration stages to isolate the sugars. The juice is also boiled so that it thickens and more crystals develop. The syrupy juice is then sent through a centrifuge to separate the crystals. The white crystals must then be granulated and packaged.

With sugarcane, the stalks are basically pulverized, and water and lime are added to produce a juice. The juice is boiled until the sugar crystallizes. The crystals are run through a centrifuge, which separates the syrup. In the final stages, the sugar goes through the refining process, which involves washing, filtration and other purification methods to produce pure, white sugar crystals. Depending on the factory, the previous stage might be skipped, and the raw sugar may be sent to other factories around the world for further processing and refining.

Sugar production can result in many byproducts, chief among them molasses. Leftover sugarcane might be used to fuel the refinery's boiler or to make paper. Molasses may also be combined with the dregs of sugar beets to make food for farm animals.

While the organic byproducts may be used, sugar production still poses some environmental problems. Transportation is a major factor, as all of that sugar has to be shipped on trucks and massive tanker ships, producing greenhouse gases. In addition, clear-cutting of land damages animal habitats, removes CO₂-devouring trees and contributes to deforestation of valuable ecosystems like the Amazon rainforest.