Kongguksu — Korea's Cold Soy Milk Noodles and the Summer Cooling Tradition

Kongguksu (콩국수) — kong (콩 = soybean) + guksu (국수 = noodles) — is Korea's summer cold noodle dish made not with kimchi broth or beef broth but with freshly made soy milk — soybeans soaked, boiled, and blended into a thick white broth served cold.

The result is unusual by any cuisine's standards: cold, white, mildly nutty, slightly sweet from the beans, completely unseasoned except for a topping of salt at the table. The broth is dense enough to be almost like drinking thin yogurt but with no sourness — pure soybean in liquid form.

The Soy Milk Broth

Making kongguksu broth from scratch:

Ingredients (serves 4):

• 250g dried soybeans, soaked in cold water 8-12 hours (or overnight)
• 1 liter cold water
• 1/2 tsp salt (minimal — most salt is added at the table)
• Optional: 3 tbsp toasted sesame seeds (blended in for richer version)

Method:

1. Drain soaked soybeans. Place in a pot with 1 liter fresh water.
2. Bring to a boil, cook 15-20 minutes until beans are completely soft.
3. Drain (save the cooking water if using — adds body to the blended result; discard and use cold fresh water for a cleaner flavor).
4. Blend the cooked beans with 1 liter cold water (cold water is critical — the cold broth must be ready cold, not re-chilled from hot) until completely smooth.
5. Strain through a fine sieve or cheesecloth, pressing firmly. Discard the solids.
6. Season with a small pinch of salt. Taste — it should be mild, nutty, slightly sweet.
7. Refrigerate until very cold (minimum 1 hour), or add ice cubes directly.

The Noodles

Traditional kongguksu uses somyeon (소면) — thin wheat flour vermicelli noodles. Very thin, white, delicate. Somen noodles (Japanese variety) are nearly identical and widely available.

Cooking: Boil in plenty of salted water 2-3 minutes. Drain. Rinse under cold running water until completely cold. Serve cold, immediately — the noodles continue to absorb liquid.

Assembly

Pour cold soy broth over a nest of cold noodles. Add ice cubes directly to the bowl. Garnish with: halved cucumber slice, toasted black sesame seeds, optional pine nuts.

Provide salt at the table — each diner seasons their own bowl.

The Summer Logic

Kongguksu's cooling properties are both physical and cultural:

• Physical: Served ice-cold, often with ice floating in the bowl
• Cultural: Soybeans are a high-protein, high-calorie summer food in Korean tradition — restorative in heat without the heaviness of meat
• Cooling philosophy: Unlike the iyeolchiyeol (fight heat with heat) tradition of samgyetang, kongguksu takes the direct approach of physical cooling

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Kongguksu is perhaps the most distinctly Korean cold noodle experience — nothing in Japanese, Chinese, or Vietnamese noodle cultures prepares you for cold soybean milk as a noodle broth. It is completely mild, completely white, completely unlike anything else. Some people find this deeply refreshing; others find the absence of sharp flavor unsettling. It is an acquired taste that, once acquired, is irreplaceable in summer.