How is sugar produced?

The natural sugar stored in the sugar cane stalk or beet root is separated from the rest of the plant material to give pure sugar.

For sugar cane, the process includes:

Extraction of the cane juice from the sugar cane, usually by crushing the sugar cane (at this stage the sweet juice contains many impurities - the soil from the fields, some small fibres and green extracts from the plant).
After settling out much of the dirt and other impurities, the juice is thickened into a syrup by boiling off much of the water (evaporation).
The syrup is placed into a very large pan for boiling and more water is boiled off until conditions are right for sugar crystals to grow.
Once the crystals have grown the resulting mixture of crystals and syrup is spun in centrifuges to separate the two (like spinning clothes in a spin drier). The crystals are then given a final dry with hot air before being stored.

This “raw sugar” is like a soft brown sugar and is stored in a large sticky heap. It can be used like that but usually it gets dirty in storage and has a distinctive taste, which most people don't want. That is why it is further refined to produce white sugar for human consumption. Additionally, because it is not possible to get all the sugar out of the juice, there is a sweet by-product made - molasses.

Sugar beet processing is normally accomplished in one continuous process without the raw sugar stage. The sugar beets are washed, sliced and soaked in hot water to remove the sugar-containing juice. The juice is purified, filtered, concentrated and dried in a series of steps similar to cane sugar processing.