Learn the science behind:
Humans have been sweetening their foods for thousands of years. Whether it’s through honey, natural sugar syrups such as maple syrup, or by using sugar beet or cane sugar, it’s all done to sweeten our dishes. Which sugar you use, used to depended on where you lived and what sugar type was available there. In regions where sugar cane grew (and grows), cane sugar is commonly used. In other areas one of the many other sweeteners might be more common.
Cane sugar grows great somewhat close to the equator and thus is commonly used in the surrounding countries. There are a lot of ways to process sugar cane into a suitable sweetener. You can either focus on completely isolating the sugar from the cane by using more advanced crystallization processes.
A more traditional process though doesn’t create beautiful ‘clean’ white sugar. Instead, the resulting sweeteners contains sugar, but also a lot of other ingredients naturally present in the sugar cane. This gives flavor bombs fully of sugar and all sorts of other ingredients. In India this product is referred to as jaggery. But, similar products can be found around the world such as panela from Southern America.
When we talk about sugar here, we’re talking about the ‘regular’ granulated or icing sugar in your cupboard. The chemical name of this sugar is sucrose. Sucrose is sweet and has some amazing properties which makes it possible to transform it into caramels, toffees, honeycomb and much more!
Sugar cane is one of two major crops grown for this sugar production. The other is sugar beet. Cane grows in (sub)tropical climates and are literally ‘canes’, full of sugar. If you chew on a cut piece of sugar cane, you will taste the sugar immediately, it’s very sweet. Cane consists of roughly (exact numbers vary between harvests and types) 70% moisture, 15% of inedible fibers with the rest being sugars and a small amount of minerals and other minor ingredients. The sugar content depends on the geographical location, the season as well as growing conditions.
Once sugar cane has been harvested it can’t be kept for long. It might dry out, sugar contents might lowering and because of its high moisture content it can actually be spoiled by micro organisms. Also, since we humans can actually eat all those fibers in the cane, we need to get rid of those. This is why the sugar cane needs to be processed after harvest, similar to how maple syrup needs to be boiled!
Processing sugar cane into jaggery
Sugar cane processing starts with the harvest. Sugar cane is harvested by cutting off the canes. As is the case for a lot of agricultural products, it starts deteriorating soon after. In warm weather, water will start evaporating and sugar (sucrose) might invert into glucose and fructose.
Processing of sugar cane can be done on a very small scale, in people’s homes as well as in huge manufacturing facilities that churn out a lot of cane sugar each year. The larger facilities tend to process the sugar more and generally produce those refined sugars we have in our kitchens. Those products tend to really be only sugar (sucrose molecules).
However, sugar cane can be processed in a lot simpler way requiring mostly just crushing of the canes and cooking the resulting syrups. This is how jaggery and similar products, are produced. Since you just cook the syrup, it contains a lot more different ingredients than refined sugar does. It has a very pronounced flavor as a result.
Step 1 – Crushing the cane
The manufacturing process continues by crushing the canes. By crushing the canes, the sugar + liquid within the canes are pressed out of the cane. Ideally, you’re left with dry cane that consists mostly of inedible fibers and a vessel full of moisture and sugars.
A crusher or mill can consist of two rolls through which you feed the cane. The rolls crush and squeeze the cane as it travels through.
Step 2- Clarifying the syrup
The juice that ends up in the pans, still contains various impurities. These impurities have to be removed during the cooking process. During boiling some of the impurities will float to the top and form a skin on the syrup. This is then skimmed of, partially purifying the sugar syrup.
Ingredients can be added at this point to help the scum raise to the surface. Commonly used ingredients are baking soda for instance, which causes a vigorous boil to help impurities raise to the surface while also increasing the pH of the solution. Baking soda doesn’t only help with impurities though. Sucrose, the sugar in cane, is prone to inversion. During inversion, sucrose, which is a disaccharide, may split into fructose and glucose (two monosaccharides). This process occurs faster in a more acidic environment, so increasing pH will slow this down.
Other alternatives for helping the scum raise to the top are various roots. Which is used depends on the region the syrup is prepared in and the availability of ingredients as well as local knowledge.
You will never end up with just sugar and water in this process. A lot of minerals and other minor ingredients will remain within the syrup.
Step 3 – Boiling the syrup
The sugar syrup at this point is still very watery with pretty low concentrations of sugar. As such, you have to boil the sugar (just like you do for maple syrup). Your aim at this point is to evaporate more moisture to concnetrate the sugar.
In smaller production locations, the end point of cooking is judged by experienced cookers. They can see whether the syrup is sufficiently cooked by observing the bubble behaviour of the boiling syrup. Manufacturers are looking for a high enough temperature so that moisture is low enough to prevent spoilage of the sugar during storage. They are looking for a temperature of 115-177°C (239-242°F). This is considerably higher than the temperature to which maple syrup is cooked. Because of this higher temperature (and thus lower moisture content), it won’t be liquid as maple syrup is. Instead, it will crystallize and solidify upon cooling, although varieties of softer jaggery exist as well.
Moulding the jaggery
Once the cane sugar solution has been cooked to a low enough moisture content, it has to cool down. The hot syrup can be poured into moulds immediately. Alternatively, it may be cooled down first before it is scooped into molds or container for further solidification and storage.
Instead of moulding the sugar, it can also be transformed into a powdery material. By forcing the sugars in the syrup to crystalilize and by moving the syrup while it is crystallizing, individual sugar crystals will form instead of one plarge block. It still is the same material though and isn’t refined sugar.
Difference to regular cane sugar
The powdered cane sugar you can buy in supermarkets is essentially a more refined version of the jaggery described here. It truly is just sucrose molecules and nothing else. This cannot be achieved by simply boiling the mixture. Instead, the manufacturing of these sugars uses a crystallization process. The sucrose crystals within the sugary solutions crystallize. As such, it is very easy to remove them from the rest of the mixture and you can end up with very pure sugar crystals. The non sugar part is centrifuged away and is what makes up molasses.
Sucrose itself doesn’t have a lot of flavour apart from its sweetness. Jaggery on the other hand, ads a lot of flavour. It has quite some bitter notes. If you haven’t had jaggery, but have had molasses, it will remind you of molasses. This is to be expected though since jaggery essentially is sugar+ the molasses since the two have not been separated in jaggery production.
Jaggery vs panela, muscovado, gur, turbinado, rapadura
A more technical definition of jaggery would be non-centrifugal cane sugar or evaporated can sugar. In other words, the sucrose has not been forced to crystallize and separate from the rest of the mixture. Jaggery is an Indian term for describing this product, but there are a lot more very similar products around the world. They might all change slightly in their manufacturing process, but are essentially the same: boiled down cane sugar syrups. Panela, muscovado, gur, turbinado, they all are very similar.
There are even more very similar sugars out there. However, they tend to not be made from cane. Instead, they can be made from palm, coconut or date to name just a few.
H. Panda, The complete book on sugar cane processing and by-products of molasses, 2011, chapter 3, link
Panela Monitor, Non centrifugal cane sugar (NCS) (panela, jaggery, gur, muscovado) process technology and the need of its innovation, April 2014, link
Max Falkowitz, How to use raw sugar: jaggery, gula melaka, panela, and more, Serious Eats, Feb-20, 2018, link