Photograph of a bowl of while sugar with a broken sugarcane stalk resting on it.


Page snapshot: Introduction to sugar from grasses, including types of sugar, sugar from sugarcane, sweet sorghum and sorghum syrup, corn syrup, and high fructose corn syrup.

Topics covered on this page: Introduction; What is sugar?; Sugar-producing crops; Sugar from sugarcane; Refined (white) sugar; Extraction of juice; Clarification and filtering; Evaporation (concentration); Crystallization, centrifugation, and drying; Refining; Cane syrup; Non-centrifugal sugar; Sweet sorghum and sorghum syrup; Corn syrup; High fructose corn syrup (HFCS); Resources.

Credits: Funded by the National Science Foundation. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Page by Elizabeth J. Hermsen (2023).

Updates: Page last updated February 16, 2023.

Image above: A broken sugarcane stalk resting on a bowl of refined sugar. Photo by Carl Davies (CSIRO Science Image, Creative Commons Attribution 3.0 Unported license, image cropped and resized).


What is sugar?

Sugar is a type of carbohydrate. Carbohydrates are molecules produced by plants that contain carbon, hydrogen, and oxygen. Typically, these elements occur in a consistent ratio. Thus, the general formula for a carbohydrate is:


Carbohydrates are also called saccharides. They come in three forms. Simple carbohydrates or sugars are monosaccharides or disaccharides. That means that they are made up of one (mono-) or two (di-) saccharide units. The other types of carbohydrates are starches (complex carbohydrates) and fiber (cellulose, a substance that makes up the plant cell wall).

In colloquial or everyday usage, sugar typically refers to sucrose. Sucrose is the substance that makes up table sugar or white sugar. It is a disaccharide. Sucrose is made up of two monosaccharides bonded together, one unit of fructose and one unit of glucose.

Diagram of a sucrose molecule, showing a hexagonal glucose molecule attached to a pentagonal fructose molecule.
Photograph of a pile of white sugar. The photo shows white crystalline sugar on a white background.

Sugar-producing crops

Sugar typically comes from one of two crop plants: sugarcane (Saccharum officinarum and its hybrids), a tall grass that concentrates sugar in its stem, and sugar beet (Beta vulgaris), a plant in the amaranth family (Amaranthaceae) that concentrates sucrose in its root. Another grass, sorghum (Sorghum bicolor), comes in a sweet variety that is less frequently cultivated to produce sorghum syrup. Because all of these plants are high in sugar, they are also targets for production of biofuels, in which sugar is fermented to produce ethanol. So far, however, only sugarcane has been heavily exploited for this purpose, mostly in Brazil.

Today, many processed foods and artificially sweetened drinks (like sodas) are sweetened using corn syrup or high fructose corn syrup (HFCS) instead of or in addition to cane or beet sugar. Corn syrup is made by breaking down the starch in maize (Zea mays) kernels and consists of glucose and water. HFCS contains glucose, fructose, and water.

Photograph of bundles of sugar cane near a market stall. The photo shows multiple bundles of sugarcane standing upright, with a few bundles laying the on the ground to the left. The sugarcane stalks are purple with regularly spaced with bands. Elongated leaves are born near the tops of the sugarcane stems.

Bundles of sugarcane that have been harvested standing near a food stall. Photo by Thamizhpparithi Maari (Wikimedia CommonsCreative Commons Attribution-ShareAlike 3.0 Unported license, image cropped and resized).

2-panel image of sugar beets. Panel 1: Photograph of a field of sugar beets, showing their large green leaves. Panel 2: Photograph of piles of brown sugar beet roots. 

Sugar beets growing in a field (left) and sugar beet roots following harvest (right). Left photo by 4028mdk09 and right photo by Stanzilla (Wikimedia Commons, Creative Commons Attribution-ShareAlike 3.0 Unported license, images cropped and left image resized).

Photograph showing a man inspecting plants in a field of sweet sorghum in Mozambique.

Original caption: "Moses Siambi (ICRISAT) looks at sweet sorghum varieties being tested for biofuel production by Eco-Energia at Ocua, Mozambique." Photo by Swathi Sridharan, 2010 (flickr, Creative Commons Attribution-ShareAlike 2.0 Generic license, image resized).

Close-up photograph of maize plants standing in a field. One of the plants nearest the camera has a ear of maize with the husk partially open, exposing the dented kernels.

Yellow dent corn in a field, Iowa, U.S.A. Photo by Don McCulley (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image cropped and resized).

Sugar from sugarcane

Sugarcane is a tall tropical grass in the genus Saccharum that is cultivated primarily as a source of sucrose. The juice in the sugarcane stem may be processed to produce refined sugar and/or other edible products. The juice or its derivatives like molasses can also be fermented to produce ethanol, which is used to make alcoholic beverages like rum and also ethanol biofuel.

Cultivation of sugarcane takes place primarily in the tropics, as sugarcane cannot survive winter freezes and needs a relatively long growing season to mature. Unlike grasses grown for grain, sugarcane is propagated asexually from whole stems or from pieces of stem called billets or setts. In regions where the climate allows, sugarcane can be grown as a perennial crop, meaning that it can be harvested and allowed to re-sprout to produce additional crops.

Photograph of people planting pieces of sugarcane stalk in furrows by hand. The photo shows a plowed field with parallel furrows in it. Pieces of sugarcane stem have been laid in a line in each furrow. In the Background, people can be seen working in the field.

People planting billets in furrows, Sevangala, Sri Lanka, 2012. Photo by Ebaran (Wikimedia Commons, Creative Commons Attribution-ShareAlike 3.0 Unported license, image resized).

Refined (white) sugar

After harvesting, sugarcane must be processed into raw sugar, a precursor to refined sugar, quickly to prevent the sugary juices in the stalks from spoiling. Thus, at harvest time, sugar milling may go on 24 hours a day, 7 days a week.

Extraction of juice

After sugarcane is harvested and transported to the mill, it is typically shredded, then crushed and washed to extract the sucrose-containing juice. The fibrous plant material left over after sugarcane juice is extracted is called bagasse. Bagasse is often burned at the sugar mill to provide power or heat.

Photograph of a truck with a load of sugarcane stem pieces pulling two additional trailers full of sugarcane stem pieces.

Truck and trailers full of harvested sugarcane, São Paulo, Brazil. Photo by Edrossini (Wikimedia Commons, public domain).

Photograph of a rotary tipler at a sugar mill in Queensland, Australia. The photo shows a yellow cylindrical frame resting on its side. Inside is a trailer full of sugarcane that is being tipped to the left.

Rotary tipler, a machine that tips trailer-loads of sugarcane to unload them at the sugar mill. Queensland, Australia, 1980. Photo by srv007 (flickr, Creative Commons Attribution-NonCommercial 2.0 Generic license, image cropped and resized).

Photograph of a modern machine used to crush sugarcane and extract the juice. The photograph shows an orange machine with large black grinding cylinders that have grooves on their surfaces. The machine is more than twice and tall as two men standing near it.

A modern machine for crushing sugarcane to extract juice. Notice the grooved rollers used to crush the cane. Photo by Sourabhpredekar (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image cropped).

Photograph of a large pile of bagasse in Phetchabun, Thailand. The photo shows a large pile of fibrous beige material with a yellow backhoe sitting in front of it. A conveyer belt runs above the pile in the background and down to the pile in the foreground. The conveyer is delivering bagasse to the pile.
Clarification and filtering

After the juice is extracted, it is clarified (meaning, impurities are removed) and filtered. During clarification, chemicals are added to the diluted sugarcane juice; these chemicals react with impurities in the juice to form solids. The treated juice sits in a settling tank, where the solids are allowed to settle out, accumulating at the bottom of the tank as a substance called mud.

The slurry of mud and some of the sugarcane juice from the bottom of the tank is collected and moved to a rotary filter, which filters out the mud. The solid mud can be recycled as a fertilizer or used for other industrial or agricultural purposes. The juice from the slurry is captured and mixed back in with unclarified sugarcane juice to go through the clarification process again. The rest of the juice, called clarified juice, moves on to the next step in processing. 

Black and white photograph of a rotary filter used to filter mud from sugarcane juice. The photo shows a cylindrical machine resting on its long edge.

Rotary filters used to filter mud from sugarcane juice after clarification, Kekaha Sugar Company, Hawai'i. Photo by David Franzen (Library of Congress, Reproduction Number HAER HI-83-39, no known restrictions).

Evaporation (concentration)

The clarified juice is next heated so that the some of the water in it evaporates, concentrating the liquid and thus raising its sucrose content. The concentrated liquid is now called syrup. Modern sugar mills use vacuum evaporators to concentrate the juice. Heating the sugary juice under vacuum means that the liquid will boil at a lower temperature than it would in an open container.

Crystallization, centrifugation, and drying

The concentrated syrup is transferred to a vacuum pan. Sugar crystals are added to the heated syrup to spur the sucrose to crystallize, producing a thick liquid called massecuite. The massecuite is moved to centrifugals that spin, separating the solid sugar crystals from the liquid in the massecuite. The liquid, called molasses, is another product of sugar; it is used as food, to make rum, or produce livestock feed. The crystals are dried to make raw sugar. 

Raw sugar produced at the sugar mill may be non-food-grade, meaning that it is not considered suitable for human consumption. The raw sugar is shipped to a refinery before it is processed further.

Photograph of sugar vacuum pans and centrifugals in a sugar factory on Réunion island. The photo shows the interior of a plant with cylindrical silver vacuum pans and a row of centrifugals that are on a floor below them. The centrifugals are somewhat difficult to see.

Vacuum pans and centrifugals in a sugar factory on the island of Réunion. Photo by David Monniaux (Wikimedia Commons, Creative Commons Attribution-ShareAlike 3.0 Unported license).

Photograph of a continuous vacuum pan in Maui, Hawaii. The pan is a white cylindrical structural resting on its long side with ports. A duct emerges from a smaller white cylinder on top of the vacuum pan. The apparatus looks like a submarine.
2-panel image showing molasses, which is a thick, dark brown syrup. Panel 1: Photograph of molasses being poured from a bottle into a glass measuring cut. Panel 2: Photograph of a spoonful of molasses, with molasses drizzling into a glass bowl below.
Photograph of a pile of raw sugar. A yellow front end loader scoops up some of the sugar in the pile. A girl in the foreground is watching the front-end loader operate from behind a metal barrier. 

Raw sugar at the Redpath Sugar Refinery, Toronto, Canada, 2010. Photo by Loozrboy (flickr, Creative Commons Attribution-ShareAlike 2.0 Generic license, image cropped and resized).


Once at the refinery, the raw sugar is melted (mixed with liquid) and passed through a series of steps to refine it: clarification, filtration, and decolorization. Afterwards, the melted sugar is heated again under vacuum to remove the liquid. The sugar is crystallized and then centrifuged again to remove the remaining molasses. If white sugar is being produced, the sugar can then be dried, packaged, and distributed. Modern, commercially produced brown sugar is typically made from refined white sugar with molasses added back. Powdered sugar or confectioner's sugar is made of finely ground sugar mixed with a little cornstarch.

Photograph of the Domino Sugar Refinery in Baltimore, Maryland, U.S.A. The photo shows a brick building with may windows. A large sign that says "Domino Sugars" is on the roof of the building, and white smoke or steam is emerging from the side. Two smokestacks can be seen in the background. The building is sitting at the edge of a body of water.

The Domino Sugar refinery in Baltimore, Maryland, U.S.A. Photo by Acroterion (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image resized).

Photograph of brown sugar. The photo shows a detail of light brown sugar crystals.
Photograph of powdered sugar or confectioner's sugar. The photo shows two clear glass measuring cups full of a powdery white sugar. A clear bag of powered sugar sits behind them.

Cane syrup

Cane syrup is produced by extracting the juice from sugarcane, straining it, then heating it so that it that it thickens into syrup. Cane syrup should not be confused with simple syrup (made by heating a mixture of sugar and water) or invert syrup (made by adding an acid to a sugar and water solution to break down the sucrose into fructose and glucose molecules). Cane syrup is a traditional product of the southeastern U.S.

2-panel image showing photographs of sugarcane grinding in Florida, 1980s to 1990s. Panel 1: A man feeding sugarcane stalks into a manual grinder. Sugarcane juice can be seen pouring into a barrel in front of the grinder. Panel 2: g in Florida. Panel 1: A man feeding sugarcane stalks into a manual grinder. In this image, a large wooden pole is attached to the top of the grinder, with a cow or ox attached to the other end of the pole. The cow is walking in a circle to operate the grinder.

Grinding sugarcane to make syrup, Florida, U.S.A. Left photo by John Marshall (1981), right photo by Nancy Nusz (1990) (Images FS821129 and FA4211, Florida Memory/State Library and Archives of Florida, public domain).

2-panel image showing photographs of sugarcane syrup making in Florida. Panel 1: A man using a large ladle to skim scum off the top of cooking sugarcane juice in a kettle. Panel 2: A man filling a glass bottle with cane syrup from a metal container. The syrup is medium brown in color.

Boiling sugarcane juice to make syrup (left) and bottling syrup (right), Florida, U.S.A., 1980s. Photos by Andrea Graham (left) and Merri Belland (right) (Images FA4167 and FA4095, Florida Memory/State Library and Archives of Florida, public domain).

Non-centrifugal sugar

Non-centrifugal sugar is a traditional solid sugarcane product with a brown color. It goes by various regional names, including kokuta in Japan, gur in India, jaggery in Africa and parts of Asia, and panela, piloncillo, or rapadura (among other names) in Latin America. Non-centrifugal sugar is made by heating and evaporating the juice squeezed from the sugarcane stalk, leaving a thick syrup. This syrup is cooled in a mold, yielding a solid sugar product.

The main difference between non-centrifugal and refined sugar is that in refined sugar, molasses is separated from the sugar syrup and the sugar is processed to produce uniform white crystals that are visible to the naked eye. While non-centrifugal sugar contains a large amount of sucrose, it is made up of very small, irregular crystals. Non-centrifugal sugar also contains other natural compounds.

Photograph of jaggery cubes. The photo shows three caramel-colored square cubes with hollow centers sitting on a white dish with a scalloped edge.
Photograph of a man making jaggery in Karnataka, India. The photo shows a man stirring cane syrup cooking in a pan in the ground with a long pole. Another pan with cooking syrup is on his left. In the background, a grinding mill and large piles of bagasse can be seen.

A man producing jaggery from sugarcane, Karnataka, India. In the photo, a sugarcane grinder can be seed in the background, next to a pile of bagasse (crushed sugarcane stalks). In the foreground, a man is stirring a kettle of cane syrup. Photo by Jedesto (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image cropped and resized).

Photograph of a man and a boy producing jaggery in Punjab, Pakistan. The photo shows a man squatting on the ground in front of a large jaggery mold. In the background, a pan of cooking cane juice with a ladle resting in it can be seen. In the foreground, lumps of jaggery sit on a blue tarp. 

Producing jaggery from sugarcane, Punjab, Pakistan. In the photo, a kettle of sugarcane syrup can be seen in the background and jaggery can be seen on the tarp in the foreground. Photo by Khalid Mahmood (Wikimedia Commons, Creative Commons Attribution-ShareAlike 3.0 Unported license, image resized).

Sweet sorghum & sorghum syrup

Sweet sorghum is a type of domesticated sorghum (Sorghum bicolor subspecies bicolor) that accumulates sucrose in its stem. Sorghum is thought to have been domesticated in tropical Africa. Nevertheless, it can be grown as an annual crop in temperate regions. In other words, while sorghum has to be replanted every year, it can grow to maturity in one growing season in temperate regions. In regions that do not experience freezing, it can be grown as a perennial crop. Thus, sorghum stands in contrast to sugarcane, which can only be grown in tropical to subtropical regions with extended growing seasons and mild winters. Sorghum is grown from seed.

Photograph of four people standing in front of a field of sweet sorghum. Three of the people watch as the forth person cuts a piece of sorghum stem.

Original caption: "Paul Cochran, a farmer from Portland, cuts slices of sweet sorghum stalk to taste for sweetness. Drs. Nilda Burgos and Leopoldo Estorninos and Jerry Gregory, a certified crop consultant from Lake Village, look on during a field day at the University of Arknasas Division of Agriculture's Rohwer Research Station." Photo source: AAES Director on flickr (Creative Commons Attribution-ShareAlike 2.0 Generic license, image resized).

Because of its high sucrose content, ability to be grown in temperate zones, and drought tolerance, sweet sorghum is seen as a potentially attractive plant for producing biofuels. Nevertheless, it is currently not widely grown for this purpose, as maize and sugarcane are the primary biofuel crops.

Sweet sorghum is grown in tropical to subtropical regions for use as human food, livestock fodder, and a source of sugary juice for making sorghum syrup, non-centrifugal sugar, and sorghum beer. Sweet sorghum is traditionally used to make sorghum syrup (sometimes incorrectly called sorghum molasses) in a process similar to that used to make sugarcane syrup in the United States. 

Black and white photograph showing a pile of sorghum stalks near a house.
Black and white photograph of a man grinding sweet sorghum stalks to make sorghum syrup. The photo shows a man feeding sorghum stalks into a grinder. A pole is attached to the top of the grinder, and a horse attached to the opposite end of the pole is walking in a circle to operate the grinder.
Black and white photograph of three women using ladles to skim the scum off cooking sorghum juice. The juice is cooking in shallow rectangular pan separated into five or six compartments by partitions.

Corn syrup

Corn syrup and high fructose corn syrup (HFCS) are made mostly from kernels of yellow dent corn, which is a type of corn that has dented kernels. Maize was domesticated in southern Mexico, but it is widely grown as a crop in the temperate zone, since it can complete its life cycle in the shorter temperate growing season.

Photograph of ears of yellow dent corn. The photograph shows six ears of yellow dent corn lined up in a row, with their tips towards the base of the image. The kernels of the ears are yellow, the a dent in the tip of each kernel.

Unlike sugar and sorghum, maize does not accumulate high concentrations of sucrose in its stem. Rather, like other grains, maize accumulates starch in its kernels. Starch molecules are complex, so they must be broken down in order to yield sugar molecules. Sugar made from maize kernel starch is used to produce corn syrup for human consumption. Sugar from maize kernel starch may also be fermented to produce ethanol, which is used to make ethanol biofuel or alcoholic beverages, like bourbon.

Production of corn syrup starts with whole maize kernels. The first step is to isolate the starch from the kernels in a process called wet milling. Wet milling involves soaking the kernels in a large vat of slightly acidic hot water. The soaked kernels are then ground into a slurry, which is spun to separate the germ (oil-containing embryos) from the other components of the kernels. The remainder of the mixture is ground again, then filtered to remove the fiber. Finally, the mixture is spun and thoroughly washed to remove the protein, leaving nearly pure cornstarch.

Starch in maize kernels consists of long chains of glucose molecules that must be broken apart. In order to do this, two enzymes are added to the cornstarch, one after the other. The first breaks the starch into simpler carbohydrates, and the second breaks the simpler carbohydrates into glucose molecules, yielding corn syrup.

Photograph of a black tanker railcar sitting on a railroad track. The side of the car has lettering, including the label "corn syrup."

Tank care carrying corn syrup, Illinois, U.S.A. Photo by Larry Darling (flickr, Creative Commons Attribution-NonCommercial 2.0 Generic license, image cropped and resized).

High fructose corn syrup (HFCS)

Today, many processed foods and sweetened beverages use high fructose corn syrup rather than cane or beet sugar. HFCS is made by treating corn syrup with a third enzyme that converts glucose molecules into fructose molecules, which are sweeter in flavor. There are several types of HFCS, which are differentiated by the percent fructose sugar they contain. The two most common used in food and drinks are HFCS 42 (42% fructose) and HFCS 55 (55% fructose).

HFCS has advantages over sucrose for food and drink manufacturers. HFCS is cheaper than sucrose. It is liquid, so it is a convenient sweetener for use in beverage production. It is also more stable than sucrose in certain processed foods and has preservative qualities, helping to keep food from spoiling.

Photograph of an ingredients label for strawberry jam that was made in the U.S.A. Ingredients are strawberries, high fructose corn syrup, corn syrup, sugar, fruit pectin, and citric acid.

Nutrient label for strawberry jam with three types of sweeteners: HFCS, corn syrup, and sugar. Photo by Food Thinkers (flickr, Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Generic license, image cropped).

Some have criticized the widespread use of HFCS in food and drink products. Some consumers dislike the flavor of HFCS. Health advocates argue that widespread use of HFCS is linked to poor health. While HFCS is sometimes singled out for contributing to conditions like fatty liver disease, diabetes, and cardiovascular disease, there is currently no evidence that HFCS is worse for health than sucrose. Rather, high sugar consumption in processed foods and sweetened drinks regardless of the form or source of sugar has probably contributed to the rise in certain health problems in the U.S. population and worldwide.

Diagram showing U.S. consumption of sugar and corn sweeteners between 1966 and 2013. The diagram shows that consumption of refined sugar was about 100 pounds per capita in 1966, dropping suddenly to about 60 pounds per capita in the 1980s. Consumption of maize-based sweeteners was low until the mid-1980s, when it suddenly rose to 60 pounds per capita around 1985 and continued to rise until the late 1990s. Overall sweetener consumption peaked in the late 1990s, and dropped to about 130 pounds per capita by 2013.
Chart showing U.S. sweetener consumption per capita, 1966 to 2013. Chart by Royote based on data from USDA (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image modified).



High fructose corn syrup questions and answers (FDA):

Sugar and sweeteners (USDA Economic Research Service):

Sugar glossary (USDA Farm Service Agency):

Sweet sorghum research (I. Dweikat, University of Nebraska-Lincoln Department of Agronomy and Horticulture):


A sweet tradition - Jasper County cane syrup: Mississippi Roads (Mississippi Public Broadcasting):

CSEC Chemistry: Extracting sucrose form sugarcane (Caribbean Toots):

How sugar is made (How It's Made, Discovery UK):

Making cane syrup the old way (The Homestead Box):

Making raw sugar (Wilmar Sugar Australia):

Making refined sugar (Wilmar Sugar Australia):

Articles & reports

Caldwell, J. 2022. Fructose is fructose is fructose (American Council on Science and Health):

Corn Refiners Association. The corn refining process. PDF:

Farm Energy. 2019. Sweet sorghum for biofuel production. April 3, 2019.

Mackintosh, D. 2000. Sugar milling. Pp. 369-377 in M. Hogarth and P. Allsopp, eds. Manual of Canegrowing. Bureau of Sugar Experiment Stations, Fergies Printers, Brisbane.

McHugh, T. 2020. How sugar is processed. Food Technology Magazine, July 1, 2020.

Rajvanshi, A. K. 2018. From food to fodder, here's how this magic plant can take care of our needs. The Better India, December 20, 2018.

Singh, J., S. Solomon, and D. Kumar. 2013. Manufacturing jaggery, a product of sugarcane, as health food. Agrotechnology, S11, 3 pgs.

Tran, G. 2015. Sugarcane press mud. Feedipedia, last updated May 27, 2015.


Levetin, P., and D. S. McMahon. 2016. Plants and Society, 7th ed. McGraw Hill Education, New York.

Simpson, B. B., and M. C. Ogorzaly. 2001. Economic botany, plants in our world, 3rd ed. McGraw Hill Higher Education, New York, New York.

Scientific articles

Parker, K., M. Salas, and V. C. Nwosu. 2010. High fructose corn syrup: Production, uses and public health concerns. Biotechnology and Molecular Biology Review 5: 71-78.