CLEWISTON — United States Sugar Corporation is one of America’s premier privately held agribusiness companies.

With state-of the art technology for both sugar refining and citrus processing, U.S. Sugar practices the most efficient and progressive farming techniques available in the world, while meeting the highest standards for worker safety, food quality and environmental protection.  The company is headquartered in Clewiston, and farms 196,000 acres in Hendry, Glades and Palm Beach counties.

“With over 2,100 employees, U.S. Sugar is the country’s largest producer of sugar cane and cane sugar, and is one of Florida’s major producers of oranges and orange juice products. It also owns a short line railroad,” Judy Sanchez, director of corporate communication said.

C.S. Mott founded U.S. Sugar in 1931. He was then one of the principal shareholders of General Motors. Today, substantially all of the company is owned by its employees and charitable foundations created by heirs of the original owners. Employees are the largest shareholder group through an Employee Stock Ownership Plan, and the company ranks among the top 50 refineries capable of producing more than 600,000 tons of refined sugar products annually.

The company operates two mills with the capacity to grind up to 45,000 tons of sugar cane each day during the six-month harvest season. One mill, the Clewiston Sugar House is the largest sugar cane processing facility in the United States.

In October 1998, U.S. Sugar officially opened its Clewiston refinery, the first new cane sugar refinery to be built in the United States in more than 25 years. Adjacent to U.S. Sugar’s Clewiston mill, this facility is the first fully integrated cane sugar refinery in the country, with a capacity of 2,100 tons per day. Refining operations include the production, packaging, and warehousing of a wide spectrum of sugar products – from small retail bags to railcars of refined sugar and tankers of liquid sugar.

The refinery is powered by natural, renewable power – electricity and steam generated at the raw mill from begasse (dried cane fiber remaining from the milling process.)

How sugar is made
Sanchez said sugar cane is a giant grass with a 12-15 month growing season, yielding three to four successive crops before it has to be replanted. Mechanical harvesters cut the stalks into foot-long lengths and harvest it.

In the fields, the cane is transferred to nearby rail cars, which transport the cane to the mills. Each railcar full of sugar cane weighs approximately 40 tons. The cars are hydraulically tilted and opened on one side, dumping the cane onto the conveying system. About 1,100 cars are unloaded every 24 hours at the two mills.

The cane is sent to a series of mills where it is crushed and the juice extracted. The sugar cane juice, which has a pH of approximately 5.5, is treated with lime and heated to the boiling point. The main purpose of liming is to neutralize the acidity and to prevent inversion of sucrose.

The combined effect of heat and lime is the formation of a heavy precipitate of complex composition. The separation of this precipitate from the clear juice is accomplished by continuous decantation in large tanks called clarifiers.

The clarified juice contains about 85 percent water. Most of this water is removed in steam-heated multiple effect evaporators operating under a vacuum. The product from the evaporation station is a high-density fluid called syrup.

The crystallization of sucrose (sugar) out of syrup or molasses is carried out in large vessels operated under a vacuum, called vacuum pans. The first step in sugar boiling is seeding. The mixture of sugar crystals and syrup or molasses is called massecuite. Sugar boiling is a complex art that requires an individual with unique skills and experience.

The crystallization process is continued in the crystallizers where the massecuite is cured by slow cooling and stirring for a period of 36 hours. This process increases the recovery of sucrose from the molasses.

Sanchez explained, the next step in sugar manufacturing is the initial separation of sugar crystals from molasses. This is accomplished by centrifugal force in batch or continuous machines called centrifugals. Basically, a centrifugal consists of a drum covered with a fine screen rotating at high speed (1,200 rpms) on its vertical axis. The molasses is forced through the screen producing a pre-refined sugar stock.

In the refinery, liquefied sugar is forced through granular carbon filters that remove the amber. The sugar liquid then moves through triple effect evaporators that remove water, creating a mixture that is 76 percent solid.

Next, the sugar is piped to pressure filters where any remaining impurities are removed. Then the sugar moves into vacuum pans for crystallization. When the crystals reach the desired size, they are dropped into centrifugals.

The centrifugals separate the crystals from any remaining liquid. The slightly damp crystals are moved to the dryer. The dryer is a moving bed of sugar and air in which the sugar is circulated over baffles and dried. A series of portholes allow the waves of sugar to be viewed as they move through the dryer.

Bucket elevators transfer the sugar to conditioning silos, where it is further dried in conditioned, dehumidified air for 24 hours, Sanchez said. Then it’s transferred to a screening tower, a series of graduated screens that separate the sugar into various sizes of granules, tailored to each customer’s specifications.

Next it’s stored in bins, according to crystal size and transferred by screw conveyors to bulk shipping or the packaging area. Bulk sugar is loaded into 200,000-pound, sanitized, food-grade railroad cars for transport to food processing companies who make candy bars, cakes, cereals, etc.

In the packaging area, machines package the sugar in two-, four-, five-, or 10-pound bags for consumers and in 25-, 50- and 100-pound bags for industrial users. Automated robots take the bags as they come off the conveyor belt and load them onto pallets, which are wrapped for shipping. They are then shipped to grocery stores for purchase.

Tours are from 10 a.m. to 2:30 p.m. Monday through Friday, October through March, with group rates available. The Sugarland Express is reserved through the Clewiston Chamber of Commerce (863) 983-7979. The tour visits the sugar mill and refinery, and includes lunch at the Clewiston Inn.  In addition, the bus goes to Southern Gardens Citrus, where people can see the outside of the structure and view the fruit going into the plant.  Since visitors are not permitted inside the plant, a video of the juice processing is shown. Total cost is $27.50 per person.