Water Chestnut & Corn Soup | IDDSI Level 3 Recipe

IDDSI Level 3 (Liquidised) | 35 minutes | Easy | Vegetarian

馬蹄粟米湯 (water chestnut and corn soup) is a classic Cantonese health soup, prized for its refreshing sweetness and cooling properties according to traditional Chinese dietary wisdom. Water chestnuts (馬蹄) have a naturally crisp texture that requires thorough cooking to become soft enough for blending; once cooked and blended, they add a subtle, clean sweetness and a mild starchy body to the soup. Combined with blended sweet corn, the result is a naturally sweet, smooth flowing liquid that meets Level 3 without any added thickener.

Ingredients (3–4 servings)

Main:

• 200g fresh water chestnuts (馬蹄), peeled (or canned water chestnuts, drained)
• 2 fresh corn cobs (or 300g frozen sweet corn kernels)
• 1 litre vegetable stock or light pork bone broth
• 2 slices fresh ginger
• 1 teaspoon sesame oil

Seasoning:

• Salt to taste
• White pepper to taste

Optional:

• 1 teaspoon honey (for additional sweetness)

Method

1. If using fresh water chestnuts, peel them carefully with a paring knife; rinse thoroughly. If using canned, drain and rinse well.
2. Strip corn kernels from the cob. Combine water chestnuts, corn kernels, ginger slices and stock in a medium saucepan.
3. Bring to a boil over high heat, then reduce to a medium simmer. Cook for 25 minutes until water chestnuts are completely soft with no resistance when pressed.
4. Remove ginger slices. Transfer all contents to a blender; blend on high speed for 2 minutes until completely smooth.
5. Pass through a fine-mesh sieve into a clean saucepan, pressing firmly to extract all liquid; discard all solid residue.
6. Return to low heat. Season with salt, white pepper and sesame oil. Add honey if desired.
7. Confirm Level 3 consistency: tilt a loaded spoon — the soup should flow slowly but continuously.

Texture Test

IDDSI Level 3 confirmation: When a spoon is tilted, the soup flows slowly and continuously, coating the back of the spoon with a thin layer. No particles of water chestnut or corn remain. The natural starch from water chestnuts provides gentle body without requiring added thickener.

Safety Notes

Canned water chestnuts — if using canned, ensure they are thoroughly cooked (simmer 20 minutes) to eliminate the firm, granular texture of the canned product before blending.

Peel fresh water chestnuts carefully — the outer skin is tough and must be completely removed. Any peel left on will create fibrous particles that pass through blending but not through the sieve.

Corn fibre — all corn fibre must be removed by thorough sieving. Do not skip this step.

Sourcing Outside Hong Kong

For international care kitchens and home cooks outside Hong Kong, Cantonese ingredients are widely available at East and Southeast Asian grocery stores:

• United Kingdom: Wing Yip (Birmingham, London, Manchester), See Woo (London), Loon Fung (London)
• United States: 99 Ranch Market (West Coast), H Mart (East Coast), local Chinatown grocers
• Canada: T&T Supermarket (national chain), local Asian markets
• Australia: Burlington Supermarket, Tang’s, local Chinese grocers in Chinatown precincts
• Singapore & Malaysia: Sheng Siong, NTUC FairPrice (Singapore); Tesco, Mydin (Malaysia)
• Online: Sous Chef (UK/EU), Amazon.com (US), Yami.com (US)

Key Cantonese pantry ingredients: East Asian grocers including Wing Yip (UK), H Mart (US/CA), T&T (CA), and Sheng Siong (Singapore) cover most items in this recipe.

If a specific ingredient is unavailable in your region, the recipe notes alternative substitutions in the Ingredients section. For dishes requiring fresh Cantonese-specific ingredients (e.g. preserved century egg, fresh rice noodle rolls), check with your local East Asian grocer before substituting — texture compliance for IDDSI levels may require specific products.

Nutrition

Approximately 105 kcal per serving (250ml), 3g protein, 24g carbohydrates, less than 1g fat. Water chestnuts are an excellent source of potassium, B vitamins and antioxidant compounds including ferulic acid and flavonoids. Sweet corn adds natural sugars, lutein and B vitamins. Together they create a low-fat, moderately caloric soup suitable for residents managing weight while maintaining hydration.

Cultural Note

In Cantonese dietary tradition, water chestnuts (馬蹄) are valued as a “cooling” (清熱) food — believed to clear heat from the body, relieve dry coughs and support digestion. 馬蹄粟米湯 is commonly prepared as a herbal soup for residents with mild respiratory irritation or dry throat. By presenting it in Level 3 blended form, this traditional health soup becomes accessible to residents at all stages of dysphagia, preserving the cultural intent of care and nourishment.