American Crystal Sugar Company is a Minnesota agricultural cooperative corporation owned by about 3,000 sugarbeet growers in the Minnesota and North Dakota portions of the Red River Valley. American Crystal is engaged primarily in the agricultural production, manufacturing and marketing of sugar from sugarbeets. The Company also sells agri-products and sugarbeet seeds.
American Crystal processes sugarbeets grown by its members in five factories. The growing area is divided into five factory districts, each containing one sugarbeet processing plant. The period during which the Company’s plants are in operation to process sugarbeets into sugar and agri-products is referred to as the “campaign.” During the campaign, each of the Company’s factories is operated twenty-four hours per day, seven days per week. The campaign typically begins in September and continues until the available supply of sugarbeets has been depleted, which generally occurs in May of the following year. An average campaign lasts approximately 250 days, assuming normal crop yields.
Harvest and Storage
American Crystal members typically begin harvesting sugarbeets on a limited basis called “prepile harvest” at the beginning of September. The prepile harvest allows the factories to begin processing while allowing the majority of the sugarbeet crop to continue maturing. Historically, American Crystal begins its’ full “stockpile harvest” around October 1. Once stockpile harvest begins, operations run 24 hours per day until the full harvestable sugarbeet acreage is lifted from field. Throughout harvest members transport their sugarbeets by truck to receiving stations designated by the Company. The sugarbeets are then stored in one of the five factory yards or one of the 33 outlying piling stations until processed. Rapid processing is important to maximize sugar extraction and minimize spoilage. Most of the sugarbeets are stored outside in piles. Frozen sugarbeets may be stored for extended periods. In most years, the cold weather in North Dakota and Minnesota offers an advantage to American Crystal as it permits the outdoor storage of sugarbeets in below-freezing weather conditions.
In order to store beets more effectively American Crystal utilizes a process called “split pile storage” in which sugarbeets from the center of the piles are removed for processing first. Split pile storage permits more of the stored sugarbeets to freeze naturally. American Crystal also was the pioneer of a ventilation technique to further reduce spoilage. In this process, fans circulate air through ventilation channels constructed within sugarbeet piles in order to pre-cool and then deep freeze the sugarbeets. Large enclosed cold storage sheds are also used to extend the sugarbeet storage period at each of the Company’s factory locations. Enclosed cold storage sheds also utilize fan ventilation to deep freeze stored sugarbeets.
American Crystal’s beet sugar processing takes place in specially designed processing facilities. At each factory, sugarbeets are washed and sliced into thin strips called cossettes. The cossettes go through a large tank called a diffuser where raw sugar juice is extracted.
The cossettes are gently lifted from the bottom to the top of the diffuser as hot water washes over them absorbing the sugar. After the sugar-laden raw juice is drawn off, the beet pulp is left behind. This pulp is processed separately and formed into pellets for livestock feed and other products (See the Agri-Products section of the Web site).
The raw juice is mingled with milk of lime and carbon dioxide gas in carbonation tanks. The carbon dioxide bubbles through the mixture forming calcium carbonate. The non-sugar particles attach themselves to the calcium carbonate and settle to the bottom of the tanks.
The juice is then filtered, leaving a golden light brown clarified thin juice. This juice is boiled under vacuum where much of the water is evaporated, forming a thicker juice similar to pancake syrup.
After a second filtration to ensure that all non-sugar materials are removed, the juice goes to the boiling pans. Once again the juice is boiled under vacuum and crystals begin to form. The resulting sugar crystal and syrup mix is called massecuite.
The massecuite is then sent to centrifuges for separation. By spinning rapidly in a perforated cylindrical basket, the molasses syrup is thrown off through the screen holes. The molasses syrup that remains after the sugar crystals are initially separated is further processed to remove more sugar crystals. American Crystal has two of these molasses desugarization facilities where this valuable residual sugar is claimed.
Clean hot water is used to wash the sugar, producing pure white sugar crystals. The damp crystals are dried with filtered air in a rotating drum granulator and the dried sugar passes over screens which separate the various sizes of sugar crystals. The sugar goes through a curing process and is then packaged into various retail and commercial packages, or into rail cars, and shipped to stores and food manufacturers.