Chilled Mung Bean and Barley Soup | IDDSI Level 3 Summer Cooling Soup

IDDSI Level 3 (Moderately Thick) | 30 minutes (plus cooling time) | Easy

Mung bean and barley sweet soup (綠豆薏米水) is one of Hong Kong’s most beloved summer drinks — a slow-simmered sweet soup of green mung beans and Chinese pearl barley (Job’s tears / 薏米) that traditional Chinese medicine associates with clearing internal heat (清熱), draining dampness (去濕) and relieving summer malaise. The traditional version keeps the beans intact, which makes it unsuitable for dysphagia diets. This adapted version cooks the beans until completely soft, blends the entire contents at high speed and strains through a fine sieve to produce a uniformly smooth IDDSI Level 3 liquid — preserving the full flavour profile while eliminating all solid particles.

Ingredients (4 servings, approximately 200ml each)

Main:

• 80g dried mung beans (綠豆)
• 50g dried Chinese pearl barley (薏米 / Job’s tears)
• 1200ml water
• 40–50g rock sugar or caster sugar (to taste)
• Food thickener (optional): only if the blended, strained liquid does not reach Level 3 naturally

Method

1. Rinse mung beans and barley separately. Soak in cold water for 1 hour to reduce cooking time (this step can be skipped if time is short — just extend simmering time by 10 minutes).
2. Drain, then place mung beans, barley and 1200ml fresh water in a saucepan. Bring to a boil over high heat, reduce to low, cover and simmer for 25–30 minutes until both the mung beans and barley are completely soft — they should crush easily between two fingers with no resistance.
3. Add rock sugar or caster sugar and stir until fully dissolved. Taste and adjust sweetness.
4. Allow to cool slightly. Pour the entire contents of the pot (liquid plus all beans and barley) into a blender. Blend on high speed for 60–90 seconds until completely smooth.
5. Strain through a fine sieve or muslin cloth, pressing firmly with the back of a spoon to extract maximum liquid. Discard all residue (bean skins, barley fibre). The resulting liquid should be completely smooth with no detectable particles.
6. Test the consistency of the strained liquid (see below). If it does not reach Level 3, add a small amount of food thickener and stir to combine, then retest.
7. Serve at room temperature or refrigerate and serve chilled — a chilled version is especially refreshing in summer.

Texture Test

Level 3 (Moderately Thick) fork drip test: Hold a fork horizontally over the liquid and observe — the liquid should coat the fork tines and drip off slowly in a thick, continuous stream rather than running off freely. When poured, the liquid should flow noticeably more slowly than Level 2 and leave a clear coating on the inside of the container. Syringe test: 10ml should flow in approximately 10–20 seconds (IDDSI Level 3 standard range).

Safety Notes

⚠️ Strain thoroughly — even after high-speed blending, mung bean skins and barley fibre fragments may remain. These must be completely removed through fine sieving. The finished liquid should feel completely smooth on the tongue with absolutely no gritty or particulate texture.

⚠️ Use thickener only if needed — well-cooked and fully blended mung bean and barley soup often reaches Level 3 naturally from its starch content. Check before adding thickener, and add in small increments to avoid overshooting into Level 4.

⚠️ Retest after refrigerating — starch-based soups can thicken further during refrigeration as starch retrogrades. Always retest the consistency of chilled soup before serving to confirm it remains within Level 3.

⚠️ Legume allergy — individuals with known allergy to legumes (mung beans belong to the legume family) should not consume this recipe.

Sourcing in Hong Kong

• Dried mung beans (綠豆) and barley (薏米): Available at all major supermarkets (PARKnSHOP, Wellcome), wet market dry goods stalls and Chinese medicine shops; select plump, uniformly coloured beans without visible damage
• Rock sugar (冰糖): Available at supermarkets in the seasoning aisle; crushed rock sugar (碎冰糖) dissolves faster than large pieces

Nutrition

Approximately 80–110 kcal per serving (200ml strained liquid, depending on sugar added), 18–25g carbohydrate, 3–5g protein. Mung beans are a good source of iron, potassium, dietary fibre and polyphenol antioxidants. Chinese pearl barley (Job’s tears / 薏苡仁) contains coixenolide, a compound studied for anti-inflammatory and diuretic properties — consistent with its traditional use in reducing water retention and dampness. This soup offers meaningful nutritional value in a texture-modified liquid form, making it a functional as well as culturally appropriate summer option.

Cultural Note

Mung bean and barley soup occupies a special place in Hong Kong’s food culture as the definitive summer cooling drink — simmered in family kitchens throughout July and August, sold at herbal tea stalls alongside chrysanthemum tea and winter melon tea, and recommended informally by grandmothers and traditional medicine practitioners alike for anyone suffering from summer heat or fatigue. Traditional Chinese medicine categorises mung bean as cool in nature (性寒) and barley as dampness-draining (去濕), making their combination a classic pairing for Hong Kong’s hot, humid summers. Serving a blended, strained IDDSI Level 3 version in elderly care settings allows residents to continue experiencing this deeply familiar seasonal ritual — not as a medical accommodation, but as a genuine cultural continuity.