Soups
Fresh Smilax, Mung Bean, and Coix Seed Soup
Traditionally helps clear damp heat and relieve skin itching, associated with supporting skin comfort
Why people make this soup
Persistent skin itching is one of those problems that quietly wears people down, particularly in hot, humid climates — or during a flare-up of eczema or hives. Traditional Cantonese food therapy addresses this kind of “damp heat” skin irritation with ingredients that help the body clear excess heat and expel dampness. Fresh smilax rhizome (土茯苓) is the star of this recipe: a large, starchy root prized for its ability to cool and detoxify. Combined with mung beans and coix seeds — both well-known for their damp-clearing and skin-supporting properties — this is a simple, practical soup that families return to whenever itchy skin becomes a nuisance.
Who it suits / who should be cautious
- Well suited to those with heat-related or damp-heat-type skin itching, eczema, acne, or skin sensitivity linked to humidity
- Can be taken 2–3 times per week during a flare-up; ease off when symptoms improve
- People with a cold or deficient constitution, cold hands and feet, or loose stools should avoid this soup or use it only in small amounts, as mung beans and smilax are cooling in nature
- A warming modification: replace the mung beans with red adzuki beans (chi xiao dou) and add an extra piece of citrus peel — this makes the soup less cooling and more suitable for those with a weaker constitution
- Young children can drink small amounts; the soup is generally considered suitable for the whole family, though in smaller portions for children
- Those taking blood-thinning medication can drink this soup
Why these ingredients (the food-therapy logic)
- Fresh smilax rhizome (tu fu ling): Sweet and neutral in nature; one of the classic Chinese herbs for clearing heat, removing toxins, and expelling dampness from the body — particularly associated with skin and urinary tract health in traditional texts. Fresh root is considered more effective than dried; once peeled, the flesh oxidises quickly to a rusty colour, which is normal
- Mung beans (lu dou): Cool and sweet; traditionally used to clear summer heat, detoxify, and support skin health. A staple in Cantonese cooling soups
- Coix seeds (yi mi): Using both raw (cooling, damp-clearing) and roasted (gentler, slightly warming) together balances the cooling effect. Traditionally associated with clearing dampness, supporting digestion, and promoting skin clarity
- Dried citrus peel (chen pi): Warm and aromatic; helps move qi, aids digestion, and moderates the cooling nature of the other ingredients
Ingredients (3–4 bowls)
| Ingredient | Amount | Notes |
|---|---|---|
| Fresh smilax rhizome (tu fu ling) | 150 g (4 liang) | Peel and cut into chunks; flesh oxidises to rust colour quickly — this is normal |
| Mung beans | 75 g (2 liang) | Rinse well |
| Raw coix seeds (sheng yi mi) | ~19 g | Rinse and soak briefly |
| Roasted / cooked coix seeds (shu yi mi) | ~19 g | Total coix = 1 liang |
| Dried citrus peel (chen pi) | 1 piece | Soak to soften, scrape off pith |
| Water | 8 bowls (approx. 2 litres) | Simmers down to about 4 bowls |
Method
- Peel the fresh smilax rhizome and cut into chunks. Work quickly — the flesh will turn rust-coloured upon exposure to air, but this does not affect the flavour or efficacy.
- Rinse the mung beans, both types of coix seeds, and the citrus peel. Soak briefly in cold water, then drain.
- Place all ingredients into a soup pot with 8 bowls of cold water.
- Bring to a boil over high heat, then reduce to a gentle simmer. Cook covered for about 2 hours until the liquid reduces to about 4 bowls.
- Serve warm. You can eat the mung beans and coix seeds; the smilax root itself is too hard to eat and is left in the pot.
Bro Niu’s tips
Fresh smilax is available at Chinese or Asian grocers, traditional medicine shops, or online. Look for pieces with white or pale flesh — that indicates freshness and quality. Dried smilax (available from Chinese herb shops) can be used if fresh is unavailable; use about 18 g (5 qian) of the dried version instead. If the soup tastes too bland, a couple of honey dates (mi zao) or Chinese figs (wu hua guo) added during cooking will improve the flavour and make the soup slightly less cooling.
Community questions answered (selected)
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Q (reader): My wife has very severe eczema. Is this soup appropriate for her? I noticed you mentioned it is somewhat cooling — is that because of the mung beans? Bro Niu: Yes, this soup is on the cooling side, largely because of the mung beans. For eczema, you can make it more suitable by replacing the mung beans with red adzuki beans and adding an extra piece of citrus peel — that reduces the cooling effect. For external relief, try boiling ground cortex dictamni (bai xian pi), belvedere fruit (di fu zi), and arborvitae leaves (ce bai ye), about 18 g each, in water for 20 minutes, then use the cooled liquid as a skin wash 2–3 times daily. It can help reduce itching and calm the rash.
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Q (容容): If I can only find dried smilax from a pharmacy, is it less effective? Bro Niu: Dried smilax works just as well. You only need about 5 qian (18 g) of the dried version.
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Q (reader, Wing): My son is 7. His fingers are red, itchy, and cracked. Can he drink this soup? I worry it might be too cooling — he also tends to have hard, pellet-like stools. Bro Niu: This smilax soup can be used; adding a few figs will also help loosen his stools. For external relief, try applying fresh aloe vera gel (cut a small section, remove the skin, and apply the clear flesh) to the affected area twice a day, leaving it on for 30 minutes before rinsing. Do not wash hands for 30 minutes after applying.
Published March 5, 2010 · Adapted and translated for Nourilo from a traditional home-kitchen recipe. Approx. 5 min read.
