Name: Korean Cold Cucumber Soup
Prep time: 5 min
Total time: 5 min
Ingredients: 1 cucumber cucumber (about 1 cup julienned); 1 1/2 cups water; 2 tablespoons soy sauce ((jin ganjang)); 4 tablespoons rice vinegar; 2 tablespoons sugar; 1 teaspoon sea salt; 1 teaspoon Korean red chili pepper ((gochukaru)); 1 green onion green onion (, chopped); 1 teaspoon sesame seeds; 1 gram dried miyeok seaweed (, optional (or ¼ cup wet seaweed))

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This Korean cold cucumber soup is crisp, tangy, and ready in just 5 minutes—no cooking required. It’s the kind of cozy-cool comfort that hits different on a hot day.

Why This Recipe Works

No cooking, all flavor: A quick broth of soy, vinegar, and sugar does all the heavy lifting while you julienne the cucumber—true shortcut energy.
Texture matters: Crisp cucumber ribbons stay tender-snappy in the chilled broth, with a bright tang that keeps you coming back for more spoonfuls.
Weeknight-friendly and flexible: Gluten-free, vegan, and customizable with or without seaweed—this refreshing Korean cold soup recipe adapts to what you have on hand.

Grocery List (& Shortcuts)

Main Players:

1 cucumber (Korean, English, Persian, or Japanese—about 1 cup julienned)
1½ cups water
2 tablespoons soy sauce (jin ganjang)
4 tablespoons rice vinegar
2 tablespoons sugar
1 teaspoon sea salt
1 teaspoon Korean red chili pepper (gochukaru)
1 green onion, chopped
1 teaspoon sesame seeds
1 gram dried miyeok seaweed, optional (or ¼ cup wet seaweed)

Smart Shortcut: Skip the seaweed if you don’t have it or aren’t a fan—this vegan Korean cucumber soup is just as delicious without it. The broth carries all the flavor.

Easy Swaps: Use regular white vinegar if rice vinegar isn’t in your pantry. Any fresh cucumber works; smaller varieties like Persian or Japanese need less prep. If gochukaru is hard to find, a pinch of red pepper flakes works in a pinch (though the flavor will be slightly different).

Step-by-Step

Prep the Seaweed (If Using)

Soak dried miyeok in lukewarm water for about 10 minutes until fully rehydrated. Drain and set aside. (Skip this entirely if seaweed isn’t your thing.)

Build the Broth

Whisk together water, soy sauce, sugar, rice vinegar, and sea salt in a bowl until the sugar dissolves. Taste it—you want a balance of salty, sweet, and tangy. This is your flavor foundation, so don’t rush it.

Prep the Cucumber

Julienne your cucumber into thin, ribbon-like strands (about 1 cup total). A mandoline makes this quick, but a sharp knife and a steady hand work just fine. You’re aiming for roughly half an English cucumber or one whole smaller variety.

Chop & Combine

Chop the green onion and set aside. Add the julienned cucumber to your seasoned broth, then stir in the chopped green onion, gochukaru, and sesame seeds. If using seaweed, add it now.

Chill & Serve

Refrigerate the soup until you’re ready to serve—at least 30 minutes, though it’s even better if it sits for a couple of hours. Pour into bowls and add a few ice cubes right before serving to keep it icy cold. The cold broth should taste bright and refreshing, with a gentle heat from the chili pepper.

Theo’s Tips

Texture is everything: Don’t skip the ice cubes at serving time. They keep the soup properly cold and the cucumber stays crisp instead of getting soft. It’s a small move that makes a real difference.
Taste as you go: The broth is your canvas. If it tastes too salty, add a splash of water. Too bland, add more vinegar or soy sauce. This soup is forgiving—adjust to what your palate loves.
Make-ahead magic: Prep the broth and cucumber the night before, keep them separate, and combine just before serving. That way, the cucumber stays crisp and the flavors stay bright.

Storage & Leftovers

Fridge: Keep the broth and cucumber together in an airtight container for up to 2 days. The cucumber will soften slightly over time, but the soup stays delicious. Add fresh ice cubes when you reheat it.

Freezing: This soup doesn’t freeze well because the cucumber texture suffers. Stick to the fridge for best results.

FAQ

Can I make this ahead? Yes! Mix the broth the night before and store it separately from the cucumber. Combine them just before serving to keep the cucumber crisp and the flavors fresh.

Is this soup really vegan? Absolutely. It’s naturally plant-based—just water, vegetables, soy sauce, vinegar, and seasonings. No animal products needed.

What’s the difference between this and other cold soup recipes? This Korean cold cucumber soup (oi-naengguk) is lighter and more vinegar-forward than many Western cold soups. The soy-vinegar-sugar balance gives it that signature tangy-salty-slightly-sweet profile that’s so refreshing on hot days.

Can I use a different type of cucumber? Definitely. English, Persian, Japanese, or even regular garden cucumbers all work. Just adjust the amount to get about 1 cup of julienned cucumber.

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Save This Recipe & Tell Me How It Went!

This refreshing Korean cold soup recipe is a game-changer for summer—quick, light, and so satisfying. If you give it a try, I’d love to hear how it turned out. Drop a comment below, save this recipe to your collection, and let me know if you added any fun twists of your own.

Stay cozy,
Theo