Sugar Making 101

The most recent post on sorghum syrup made me realize something important: in spite of all the jabbering I’ve been doing about molasses and table sugar, I haven’t written a thing about how either one are made. It’s a slightly complex process, yet here it is in a nutshell:

Sugar has of course traditionally been made from sugar cane. Sugar cane contains a sucrose-heavy juice that’s extracted by crushing the stalks in a press. The juice that emerges from the stalk contains a wide variety of non-sucrose substances like water, complex sugars, proteins, and assorted bits of organic matter. These are the impurites that the sugar making process was created to remove.

Sugar making begins by heating the juice with a small amount of lime. This has the effect of coagulating most of the impurities so they can be skimmed off. Next, the water is boiled off to produce a highly concentrated dark brown syrup. It’s here that the really interesting part happens: crystallization.

Left to their own devices, the densely packed sucrose molecules in dark brown syrup would eventually start to bond to one another to form crystals. But this takes time, and so “seed” crystals are added to hasten the process. As the seed crystals set about propagating themselves, the syrup is spun in a centrifuge which separates it into sucrose crystals (raw sugar) and so-called “first” molasses, the sweetest of the three main molasses types.

At this point the molasses can either be packaged and sold, or it can be put through the crystallization process a second time. The second pass through the centrifuge yields more raw sugar and “second” molasses, a rather less-sweet iteration of the first. If crystallization is done a third time, the result is still more raw sugar and “blackstrap” molasses, a highly concentrated goo made of leftover non-crystallized sucrose, complex long chain sugars, and all the other assorted and sundried substances that the coagulation process didn’t filter out.

From there the raw sugar goes to the refining stage, where it’s washed, dissolved once again in hot water and clarified. The final pass through the cetrifuge yield’s refined white sugar, plus so-called “refiner’s syrup” which, when heated with a touch of acid makes so-called “golden syrup” like Lyle’s