Chinese Mung Bean Soup {Tau Suan}
A Singapore favourite, shelled mung bean soup or ‘tau suan’ as it is known in Hokkien dialect terms, is a much loved dessert which many of us can easily enjoy at local hawker food centres.
This dessert is always served hot and garnished with cut slices of crispy Chinese cruellers or ‘you tiao’.  In fact, this food pairing is almost inseparable, so much so that it would be considered a huge disservice if dessert stalls were to offer this soup without ‘you tiao’.
This highly nutritious soup can just as easily be prepared at home, and very inexpensively at that, for your family and friends to enjoy. Mung beans, whole or shelled, are a rich source of dietary fibre, very low in saturated fat and cholesterol-free. They are often used in diet and weight management as the high fibre content slows digestion, which helps stabilize blood sugar, and reduces hunger pangs.
In Chinese food therapy, mung beans are highly valued as a tonic food. It is cool in nature, and as such, are used to treat heat-induced symptoms and illnesses. Â Mung beans help clear heat, which often manifests physically as thirst, red face, constipation, lack of energy, dry skin, headaches and dizziness.
It helps eliminate toxins from the body, balances the organs and tonifies qi. It is also used to treat acne and other skin related symptoms such as the common skin rash, cold sores, mouth ulcers, pimples and boils (source: www.pingminghealth.com)
SHELLED MUNG BEAN SOUP (TAU SUAN) RECIPE
Serves 4 to 6 persons.
Ingredients:
250 gm shelled Mung Beans
4 Pandan (Screwpine) Leaves tied into knots
100 gm Rock Sugar, or to taste
6 cups Water
4 to 5 tbsp Water Chestnut Flour (or Caltrop Starch)
  mixed with equal parts of water, for thickening
Method:
1. Â Wash shelled mung beans in several rinses of water until water runs clear and is almost colourless. Soak in water (ensure that there is at least an inch of water above the beans) for an hour. Drain, and discard the water.
2. Â Spread mung beans in a thin layer on a steam tray or heat proof dish. Steam for 15 to 20 minutes, or till just cooked through. Do not steam too long, otherwise the beans will be overcooked and easily turn mushy or disintegrate when it is later added to the liquid.
3. Â Fill a pot with water, add pandan leaves and 2/3 of the rock sugar. Bring to a boil, remove pandan leaves once liquid is boiling. Once rock sugar is completely dissolved, taste for sweetness and add remaining sugar, or more, if desired. When satisfied, add the water chestnut flour solution, stirring again just before pouring in, little by little. The liquid should come to a gluey like, thick starchy consistency. Prepare additional thickening solution if required.
4.  Once thickened, pour in the cooked mung beans and stir to distribute evenly throughout the soup. Do not stir too frequently, just enough to mix well, otherwise the starch may start to break down and turn watery. Turn off heat, dish out into individual serving bowls, garnish generously with cut slices of ‘you tiao’ and serve hot or warm.
Some things to note:
#1. The cooked mung beans are added at the end, after the soup has been sweetened to taste and thickened to the right consistency. This prevents the soft, cooked beans from turning mushy too quickly, and potentially ruining the texture and appearance of the soup.
#2. It should also be thickened considerably, as is characteristic of this dessert, similar to a gluey like texture. Normally, I would say to thicken to your desired consistency, but that is not the case here if you wish to stay true to the authenticity of this dessert.
#3. The use of water chestnut flour or caltrop starch solution as a thickener is preferred, as it imparts a lovely, clear sheen to the soup, and adds just a subtle hint of the mildly sweet water chestnut flavour. The thick, starchy consistency also holds the beans in a suspension, which makes for better appearance and presentation.
Hi Celia, thanks for your advice. Can I use corn flour instead?
Hi Audrey, ideally tau suan will stay thick (starchy) for longer with water chestnut flour or sweet potato flour, and also gives it that glossy appearance. You can still thicken tau suan with corn flour but it may turn watery after a couple of hours (unless you expect that it’ll be finished up quickly..heee):p. Using potato starch is also another alternative. Hope this helps! Regards, Celia
Hi Celia, can’t find water chestnut flour from supermarket.
Hi Audrey, you can get it at some wet markets, or substitite with sweet potato flour. I think I’ve seen Phoon Huat outlets stock both kinds of flour/starch in Singapore. Cheers, Celia