In the marmalade
If you get the reference in the hed and dek, did you have a Tamagotchi? Or a Baby G? Were you a Leon fan or did you love Aaron’s moves more? (Sorry, this was for a very specific audience, but it’s the first thing I think of when I think of the word “sugar” – Cantopop is full of earworms like these. I’ll stop now. There is no other marmalade-related content in this newsletter.)
Ok, sugar. It’s the devil, right? Just like fat was in the early aughts. But I’m not here to talk about nutrition and nutrition reporting (although it’s super interesting and later I might dive in further than my labelling post), I just want to geek out a bit over sugar, in particular Chinese rock sugar.
This interest sparks from a couple of things. The first was that I started making kombucha regularly a while back, and SCOBYs (symbiotic culture of bacteria and yeast) reportedly work best with certain types of sugars (the theory is, the simpler the better). The second is that I’ve always wondered why we use rock sugar in Chinese braises, such as my favourite 12345 spare ribs, or for beef brisket in clear broth (I just tried this recipe from Teresa Mak, respected Hong Kong cook aka Dashijie, which created a most delightful pho-like broth with surprisingly little work).
First of all, Chinese rock sugar is actually not much different from white granulated sugar, it’s mostly sucrose, a disaccharide (two sugar molecules), made up of one glucose molecule bonded with one fructose molecule (these are both monosaccharides, or simple sugars, the most basic molecule of carbohydrates). I say mostly, because the rest is water – yes, water! Probably at around 1%. The sugar can be derived from sugar cane or sugar beet – both are readily used these days. (Confusingly, both sucrose and cane sugar are called 蔗糖, “cane” sugar, in Chinese).
I guess I should quickly go over how white sugar is made in the first place (if you know, skip this paragraph). The gist of it is: you take sugar cane or sugar beets, press the juices out, then heat, filter, refine and crystallise, separate the molasses, clarify and crystallise again, take out the moisture – et voilà, white sugar. Some of these are processes that require other chemicals, others are physical (eg. filtration, centrifuging).
A lot of people, Chinese included, think rock sugar is a less refined form of sugar and therefore healthier, but that’s not necessarily the case, at least though the lens of Western science, and the industrial processes used to create the rock sugar we buy today. In the olden days, rock sugar may have been the first crystallised rocks with the molasses washed off (so more like giant rocks of raw sugar), but I can’t be sure, because there’s surprisingly little written about it. In today’s processes, rock sugar is made simply by dissolving white granulated sugar in water, boiling off most of the water, and taking a small crystal of sugar as a “seed'“ for “growing” larger crystals in the super concentrated syrup (basically, when aided by a little water, sugar crystals like to bond to each other to create larger versions of themselves). Each “rock” is, in fact, a giant crystal.
There are two types of rock sugar found in Hong Kong (and I’d say most of East Asia) – monocrystalline and polycrystalline. There are lots of prefixes flying around, but this mono- and poly- are more to do with the production process, not the glucose/sucrose structure. Monocrystalline is made by dipping a sugar crystal continuously in and out of the concentrated syrup – each dip creates a new layer of crystallisation, and because this process is totally mechanical, the “rocks” tend to be quite uniform in shape. Polycrystalline rocks are made by bathing crystal seeds in the syrup and letting the water slowly evaporate, so the crystals form in a more “natural” manner and you end up with all sorts of shapes and sizes. But in terms of what they’re made of – it’s still white sugar. (If there’s a slight yellow hue, some of the molasses is probably still attached to the sugar, so there probably are trace minerals in it, but I wouldn’t rely on rock sugar to give you your mineral intake!). Generally in cooking, we use polycrystalline, but I think it’s more to do with the fact that poly usually has a teeny weeny bit of molasses whereas mono is usually triple clarified and extra white as it’s recommended for drinks (eg. umeshu or iced tea), not because of the way the sugar crystals are formed.
In Traditional Chinese Medicine, polycrystalline rock sugar is seen to be good for the lung and spleen meridiens, so for coughs, is often used alongside ingredients like pears. Monocrystalline rock sugar isn’t seen to have any such benefits. Although I wonder if anyone has told TCM practitioners about the industrial processes used these days?
Back to cooking – why is it used so much in Chinese cooking when there is now granulated sugar? (Arguably much easier to use – no pre-bashing needed.) One of the common arguments (apart from perceived health benefits) is that is has a more subtle flavour, and there may be a point to that. I think there are a couple of reasons for this – one, that the water content means there is really slightly less sugar, and two, the flavour change is more subtle while cooking, because the larger chunks (even crushed, they're coarse) take longer to dissolve.
Most Western caramel recipes ask you to add a little water to your white sugar – apart from reducing the risk of burning, it allows the sugar more time to caramelise. Caramelisation isn’t just about colour; it’s about flavour development too, so the water allows the aromatic compounds to start developing; and according to the section on sugar caramelisation in On Food and Cooking by Harold McGee, cooking sugar for longer also makes it less sweet.
To take it back to the Chinese dishes I mentioned above, in 12345 spare ribs (which is more or less a hongshao method – soy, sugar, Shaoxing wine, rock sugar to finish), the larger rocks mean that the sugar is less likely to burn, and the slower cooking makes it less sweet but develops nice caramelised flavours. In the case of beef brisket in clear broth, where there’s a lot of liquid, the heat is super gentle and wouldn’t burn granulated sugar anyway; the larger chunks are probably there for that flavour development from slow cooking, including the fact sweetness would be reduced, since it’s cooked for at least 5+ hours (by the way, I used my vacuum pot and made it overnight – it requires zero energy and is perfect for holding a constant temperature; I don’t know why people don’t talk about it more).
Most English-language Chinese cookbooks say to substitute rock sugar with granulated if you can't find it, which I guess works, but you will lose a bit of that subtlety. I would guess, after reading all this, to maybe try adding a splash of water into your sugar before adding it to your dish, to at least slow it down a little? I’ve never tried this before, to be honest, so let me know if you do.
I’ve also started using rock sugar for my kombucha. I recently made a batch using First Flush darjeeling (a press gift from TWG I got a while back), and the results were amazing – it tastes a little like some of the funkier natural white wines out there, (Garo’vin Lunatic comes to mind) and I’m so happy with it. Before that batch I’d been using regular black teabags plus rock sugar, and it does taste a bit better (more mellow, less acid even after letting it ferment for longer) than the table sugar versions. But for kombucha, the sugar is dissolved, so physical crystal size shouldn’t be an issue. Perhaps it’s because rock sugar is simply less sugar (I’ve been using the same weight of sugar whether I’m using rock and table), so the SCOBY goes a little slower and you get less astringent acid (too much sugar and you get a kombucha that’s both too sugary and too sour). The Noma Guide to Fermentation says 12% sucrose is ideal, but I’ve gone with recipes that are about 4-5% and worked great, so not sure what’s going on there, but sugar in fermentation is a whole other topic that I won’t get into today.
If you found this interesting, why not forward it to a friend?
The pretzel croissant at Bakehouse: chewy and dense like a pretzel, flaky and buttery like a croissant. Do it.
Chicken rice at Bâtard: waxy and al dente, full-flavoured; I know tons of French-ish places do whole roast chickens + sides in Hong Kong these days, but this side wins. Chicken was fine a little ho-hum, but I’m told it’s about to change… And oh yes, important point: it’s attached to The Fine Wine Experience, so all the wine is at retail price.
This episode of Washington State University’s Wheat Beat Podcast featuring Dr. Rattan Lal of Ohio State University (and recipient of The World Food Prize this year), in which Lal talks about healthy soil being the biggest carbon offset opportunity that we’ve totally missed. Just 1 ton of carbon sequestered in soil can offset up to 15% of global emissions – this means a 2% increase in carbon in all the soil around the world is all it takes to offset all our current emissions (and increase food security and quality etc.). Amazing stuff!