Sugar starts as sunlight. Plants like sugarcane and sugar beets use photosynthesis to convert carbon dioxide and water into sucrose, which they store in their stalks or roots. Getting that sucrose out and into the white crystals you recognize involves crushing or slicing the plant, extracting the juice, purifying it, and evaporating the water until sugar crystals form. The global sugar industry produces roughly 189 million metric tons per year using this basic sequence, though the specifics differ depending on whether the source is cane or beets.
How Plants Create Sucrose
Sugarcane and sugar beets both manufacture sucrose through photosynthesis, but they do it a bit differently. Sugarcane is a tropical grass that uses an especially efficient form of photosynthesis (called the C4 pathway), which lets it thrive in intense sunlight and high temperatures. Inside the plant’s cells, carbon dioxide is fixed into small sugar molecules, which are then linked together to form sucrose. That sucrose travels from the leaves down into the stalk, where it’s stored in the cells’ fluid-filled compartments called vacuoles. A mature sugarcane stalk is roughly 12 to 14 percent sucrose by weight.
Sugar beets take a different storage approach. These root vegetables, grown in cooler climates like northern Europe and parts of North America, pack sucrose into their large taproots. A sugar beet root is 75 to 85 percent water and up to 21 to 22 percent sucrose, making beets slightly more sugar-dense per pound than cane. In both cases, the chemistry of the sugar itself is identical: pure sucrose, regardless of the plant source.
Sugarcane Processing: Stalk to Raw Sugar
Once sugarcane is harvested, it moves through a series of mechanical and chemical steps at the sugar mill. The hard stalks first pass through revolving knives and shredders that break open the fibrous structure. Then the crushed cane feeds through multiple sets of heavy rollers, typically arranged in groups of three, that squeeze out the juice. Water is sprayed onto the crushed cane between roller sets, a step called imbibition, to wash out as much remaining sugar as possible. The dry, fibrous material left after the final roller is called bagasse.
The extracted juice is strained to remove large particles, then clarified using heat and lime. Lime raises the pH and causes impurities to clump together into a heavy sediment called “mud,” which settles out by gravity or gets spun off in a centrifuge. What remains is a clear, amber-colored juice.
This clarified juice enters large evaporators that boil off water in stages, concentrating it into a thick syrup of about 65 percent solids. The syrup gets another round of clarification, then moves into vacuum pans, which are sealed vessels that boil the syrup under reduced pressure. Lower pressure means lower boiling temperatures, which prevents the sugar from caramelizing or breaking down. As water continues to evaporate, the syrup becomes supersaturated, meaning it holds more dissolved sugar than it normally could. At that point, workers introduce tiny seed crystals or “shock” the solution, triggering sugar crystals to form and grow.
The resulting thick mixture of crystals and liquid, called massecuite, is discharged into a crystallizer to let as much sugar as possible come out of solution. Then it’s fed into high-speed centrifuges: spinning baskets that fling the liquid outward through a perforated wall while the crystals stay behind. Steam is introduced during the spin to improve drainage, which can boost molasses removal by about 50 percent compared to spinning alone. The crystals get a water wash inside the centrifuge, and the liquid spun off is molasses. This entire crystallization and centrifuge cycle is repeated two or three times on the leftover molasses to recover additional sugar. The result is raw sugar: tan-colored crystals coated in a thin film of molasses.
Sugar Beet Processing: Root to White Sugar
Sugar beets follow a different extraction method because the sucrose is locked inside root cells rather than juice-filled stalks. After harvesting, beets pass through an extensive cleaning system that removes dirt, rocks, metal debris, and leaf tops. Water flumes carry the beets through rock catchers, sand separators, magnetic metal separators, and spray nozzles before the roots are lifted out and sent to processing.
Clean beets are sliced into long, thin strips called cossettes, which look a bit like thick shoestring fries. These cossettes travel through a continuous diffuser where hot water, maintained between 122°F and 176°F, flows in the opposite direction. As the cossettes move one way, hot water moves the other, steadily dissolving sucrose out of the beet tissue. The sugar-enriched water that comes out, called raw juice, contains 10 to 15 percent sugar.
From here, the process converges with cane processing. The raw juice is purified (beet factories commonly use a method called carbonation, where lime and carbon dioxide remove impurities), then evaporated and crystallized in vacuum pans the same way cane syrup is. One key difference: beet sugar factories typically produce white sugar directly, skipping the separate refining step that cane sugar requires.
Refining Raw Sugar Into White Sugar
Raw cane sugar still has that molasses coating, so it needs refining to become the white granulated sugar sold in stores. At the refinery, the raw crystals first go through affination, a washing step that strips off the outer molasses layer. The sugar is then dissolved in water, and the resulting syrup goes through clarification again using lime and phosphoric acid or carbon dioxide.
The crucial step is decolorization, which removes the brownish color compounds still dissolved in the syrup. Refineries use one of several methods: bone char (charcoal made from cattle bones), granular activated carbon, or ion-exchange resins. Some facilities combine these approaches. Bone char has been used for centuries and remains in use at some refineries, though ion-exchange and activated carbon systems have become common alternatives. After decolorization, the clear syrup is evaporated and crystallized one final time, producing the pure white crystals that are dried, sieved by size, and packaged.
Chemically, there is no difference between sugar from cane and sugar from beets. Both are pure sucrose. The only distinctions arise during processing, and those disappear entirely once the sugar is fully refined.
What Happens to the Byproducts
Sugar production generates several valuable byproducts. Bagasse, the fibrous cane material left after juice extraction, is burned as fuel to power the sugar mill itself, making many cane operations partially or fully energy self-sufficient. It’s also used to make paper, fiberboard, and biodegradable packaging.
Molasses, the dark syrup separated during centrifugation, goes into animal feed, rum and alcohol production, and fermentation for industrial chemicals. The beet equivalent produces its own molasses with a slightly different flavor profile, used primarily in animal feed and yeast production.
Sugar beet pulp, the leftover beet tissue after sucrose has been extracted by diffusion, is produced in enormous quantities. Hundreds of millions of kilograms are generated annually. Most of it is dried and sold as animal feed, though researchers have found it can also serve as a growth medium for producing protein-rich yeast biomass, since the pulp still contains significant amounts of fermentable carbohydrates.
Where the World’s Sugar Comes From
About 80 percent of the world’s sugar comes from sugarcane, grown in tropical and subtropical regions. The remaining 20 percent comes from sugar beets, cultivated primarily in temperate climates. For the 2025/26 season, global production is forecast at about 189 million metric tons. Brazil dominates, producing roughly 44 million metric tons, nearly a quarter of the world total. India follows at about 35 million tons. The European Union, relying almost entirely on sugar beets, produces around 15.5 million tons. China, Thailand, and the United States round out the top producers, with the U.S. contributing about 8.5 million tons from a roughly even split of cane (grown in Louisiana, Florida, Texas, and Hawaii) and beets (grown in the northern plains and upper Midwest).
Environmental Costs of Production
Sugarcane harvesting has traditionally involved burning the fields before cutting, which clears the sharp leaves and makes manual harvesting faster. This practice releases carbon dioxide, carbon monoxide, methane, particulate matter, and volatile organic compounds into the air. Communities near burning fields report respiratory problems, particularly asthma, along with visible pollution they describe as smoke, dust, and “black snow.”
The alternative, green mechanical harvesting, skips the burn and cuts the cane with machines. It leaves 10 to 20 tons per hectare of leaf and stalk residue on the ground, which acts as a natural mulch. Over time, this trash blanket preserves soil moisture, suppresses weeds, adds organic matter as it decomposes, and supports a healthier population of soil microorganisms and insects. Farmers who burn their fields consistently report declining soil fertility, compaction, and higher input costs over the long term. Green harvesting also increases cane yields over multiple growing seasons, even though burning shows no yield penalty in the short run. The transition has been slow in some regions because mechanical harvesters are expensive, but environmental regulations and air quality concerns are steadily pushing the industry toward green methods.