A SINGAPORE PRESS HOLDINGS WEBSITE
How to avoid watery tau suan.
Ask the Foodie
Q: I love tau suan and I have tried preparing it. I’ve had different advice from different people, such as using sweet potato flour, cornstarch and even water chestnut starch. However, I just can’t seem to get the right consistency. It’s either too watery even while hot or it solidifies into a pot of “kueh” when cooled. Is there a secret recipe that hawkers are keeping to themselves? -Michelle Tan Mei Lin
A: Intrigued by the variations in different tau suan recipes, I set out to investigate. I collected 11 thickeners: rice flour, glutinous rice flour, sago flour, potato starch, sweet potato starch, arrowroot starch, mung bean starch (hoon kueh flour), cornstarch, tapioca starch, water chestnut starch and wheat starch (tang mien).
I dissolved 5g of each starch in 150g water, then brought each solution just to a boil over medium heat, stirring constantly, before taking it off the heat.
Here are the results: Gritty water chestnut starch needed to be crushed to a powder before being dissolved, but in the end, had the best mouthfeel, velvety and smooth without being too sticky.
Second best was sweet potato, followed by sago and then potato. Tapioca, the only one of all the starches to not form a skin on cooling, had the stickiest, gummiest mouthfeel.
Arrowroot had the most neutral flavour and sweet potato starch had a non-neutral but pleasant, very faintly sweet taste that I imagine would be compatible with most Asian desserts. Potato starch had the most colourless and also most translucent appearance. Sago flour, curiously, had a noticeable pinkish tint.
As for thickening ability, rice and glutinous rice were the most powerful thickeners, followed in order by potato starch, sago flour, water chestnut starch, sweet potato starch, wheat starch, tapioca starch, arrowroot, cornstarch and finally, mung bean starch.
So here is a tau suan recipe: Begin by soaking split, skinned mung beans in water for 30 minutes. Drain them well, then spread them in a wire sieve and steam over high heat for 20 to 25 minutes, until tender. Taste the beans frequently after the first 15 minutes to check if they are done.
Rinse the cooked beans lightly under running water and set aside. Simmer knotted pandan leaves with rock sugar – some cooks also add dried tangerine peel – to make a light syrup, sweetened to suit yourself.
For every litre of syrup, dissolve 20g of water chestnut starch and 15g of potato starch in a little water, then stir into the syrup and simmer for a few minutes until it thickens. Stir in the mung beans, and when the tau suan just comes up to a boil, turn off the heat. Serve immediately.
Once most starches reach their thickening peak, further stirring and heating will thin them out, so if you want to make tau suan in advance, cook the mung beans and make the syrup first, then thicken and assemble the dessert just before serving.
