Icy-Cold Korean Cucumber Soup (Oi Naengguk) Recipe

Using only a few key ingredients, this refreshing Korean cucumber soup delivers tons of savory flavor.

A refreshing serving of Korean cucumber soup with thin stands of cucumber, sesame seeds, and ice cubes floating in a light broth.

Serious Eats / Vicky Wasik

Why This Recipe Works

  • Korean and English cucumbers have a thinner skin and higher ratio of flesh to seeds, which works well for the matchstick-thin strips needed here.
  • Traditional Korean Joseon 100% soy sauce adds a salty, savory flavor, without the sweetness of soy-and-wheat-based yangjo soy sauce.

There may be nothing better for beating the heat than this icy, savory cucumber soup. Thin strips of fresh cucumber infuse the water with a cooling, refreshing flavor, while soy sauce and vinegar add bright, savory, and salty notes. Once those are mixed together, a generous addition of ice cubes keeps the soup perfectly chilled with every bite.

If you want, you can add a small amount of rehydrated and blanched miyeok (wakame) seaweed to the bowl as well, or even very thinly sliced onion and julienned carrot. While it's not traditional, a little julienned apple is a nice touch, too; in that case, just be sure to serve the soup right away, before the apple can brown.

Recipe Details

Icy-Cold Korean Cucumber Soup (Oi Naengguk) Recipe

Prep 20 mins
Active 20 mins
Total 20 mins
Serves 4 servings

Using only a few key ingredients, this refreshing Korean cucumber soup delivers tons of savory flavor.


  • One 1-pound (500g) cucumber, preferably Korean or English (about 8 to 10 inches/20 to 25cm long; see note)

  • 4 medium cloves garlic, finely minced

  • 2 1/4 cups (500ml) cold water

  • 2 tablespoons (30ml) Joseon ganjang (Korean soup soy sauce; see note)

  • 2 tablespoons (30ml) Korean yangjo vinegar (brown rice vinegar; see note)

  • Kosher salt

  • 18 ounces ice cubes (500g; the equivalent of 2 1/4 cups/500ml water frozen into cubes)

  • 1 teaspoon roasted sesame seeds


  1. Cut cucumber into roughly 4-inch (10cm) lengths. Using a knife or mandoline, julienne the cucumber as finely as you can.

  2. In a large mixing bowl, combine cucumber with garlic, water, soy sauce, and vinegar, stirring to distribute ingredients. Season with salt. Transfer to refrigerator if not serving right away.

  3. When ready to serve, add ice cubes and season once more with salt, if needed. Sprinkle sesame seeds on top. Ladle into individual bowls, along with the ice cubes, and serve.

Special equipment



Standard, waxy American cucumbers have a skin that's too thick and heavy, as well as an overabundance of seeds; they're best avoided here.

See our guide to the Korean pantry for more on Joseon ganjang and yangjo vinegar, including brand recommendations.

Make-Ahead and Storage

The julienned cucumber, garlic, water, soy sauce, and vinegar can be combined, seasoned with salt, and kept refrigerated up to 4 hours before the ice is added and the soup is served.

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Nutrition Facts (per serving)
33 Calories
1g Fat
6g Carbs
2g Protein
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Nutrition Facts
Servings: 4
Amount per serving
Calories 33
% Daily Value*
Total Fat 1g 1%
Saturated Fat 0g 0%
Cholesterol 0mg 0%
Sodium 531mg 23%
Total Carbohydrate 6g 2%
Dietary Fiber 1g 3%
Total Sugars 2g
Protein 2g
Vitamin C 4mg 22%
Calcium 43mg 3%
Iron 1mg 3%
Potassium 234mg 5%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)