Rather than carting all that sugar cane around the world, the milling process starts right where it’s grown. Sugar mills do the job of stripping away all the woody bits of the cane, and turning it into sticky syrup.
It used to be that farmers would set fire to their cane fields just before harvesting. This would get rid of all the leaves and make it easier to harvest. These days the sugar cane is simply harvested when it’s still green. That way, it’s easier to cut, and the farmers can use the leaves and other cuttings to fertilise the soil – much less wasteful!
The cane is then taken to a shredder where it is chopped and shredded up into little teeny bits. Then a big pair of rollers feed the cane bits through a series of special roller mills. These are designed to squeeze the sugary juice from the woody bits of stalk. The woody stalks look like rubbish, but they aren’t thrown away. The mill uses them to fuel their boilers!
The next step is to add milk of lime to the sugary juice and boil it. This helps get rid of any impurities like tiny fibres from the woody stalk or grit from the soil. After that, those impurities settle on the bottom, so the clear sugar juice can be poured off the top.
The sugar juice is then pumped into air-tight pans where it’s boiled under vacuum to evaporate the water off, so that raw sugar crystals form. The juice is then separated in a centrifuge, which is like a giant washing machine set to spin cycle.
The juice separated off is called molasses and the raw sugar crystals are ready to be shipped to factories like Chelsea.
