Raw sugar, transported by boat, is covered with a thin coat of molasses, residual plant matter, and particles from shipping and handling. It must undergo purification at a cane sugar refinery before it is ready for human consumption. The first step is to remove the thin coat of molasses and residual matter from the raw sugar crystals. This is accomplished by blending the raw sugar in a hot syrup and then spinning off the dark brown syrup (molasses) from the sugar in high speed centrifuges. The raw sugar crystals are then dissolved in water and filtered through a mechanical ‘strainer’ to remove the remaining suspended solids and colour. The result is a pure, colourless syrup composed of sugar and water.
The sugar syrup is concentrated through evaporation (boiling under vacuum) and tiny “seed” crystals are added, allowing larger sugar crystals to form. Granulated sugar is obtained by extracting these crystals from the syrup by spinning in centrifuges (like a washing machine).
The crystals are dried in a drum (like a laundry dryer) and stored in silos. Prior to packaging, the sugar is sieved through wire mesh with various sizes of holes to separate crystals that correspond to different varieties of sugar (e.g., fine, superfine, coarse).
Cane Sugar Refining By-Products – Much of the water removed from the syrup still contains sugar, so it is pumped back into the system to be used again. Molasses is recycled through the cane sugar refining process an average of four times to remove the maximum amount of sugar from it. Molasses is also used by distillers, bakers and pharmaceutical companies, and can be used in the manufacturing of yeast products.
