Cucumber Kimchi (Oi Kimchi) — The Ultimate Summer Kimchi

A Crisp, Quick Fermenting Summer Favorite

If there’s one kimchi I can’t go a summer without, it’s cucumber kimchi. Known as oi kimchi (오이김치) in Korea, this refreshing, quick-fermenting kimchi is one of the most beloved summer side dishes. Crunchy, tangy, and slightly fizzy when fermented just right. It’s the kind of kimchi that’s ready in days, not weeks!

In this small-batch version, I’m sharing how I make cucumber kimchi at home using ingredients that are accessible wherever you are. It’s a simple method that lets the crisp cucumber flavor shine, as long as you avoid one common pitfall: mushiness. Don’t worry, I’ll show you exactly how to keep it crisp.

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What Is Oi Kimchi (오이김치)?

In Korea, oi kimchi is a go-to summer dish. It’s light, quick to make, and incredibly refreshing when served cold. Unlike cabbage-based kimchi, cucumber kimchi ferments much faster and is usually enjoyed fresh or within the first couple of weeks. It’s not only served as banchan (side dishes to accompany rice) on the dining table, but often paired with cold noodles, Korean BBQ, and much more!

One of the most iconic forms of cucumber kimchi is oi-sobagi (오이소박이), cucumbers slit and stuffed with a filling of garlic chives, radish, and seasoning. It’s beautiful and delicious, but also more labor-intensive and best suited for firmer cucumbers that can hold the stuffing.

The version I’m sharing here is a simpler, loose-style kimchi, like mak kimchi (cut cabbage kimchi) is to pogi kimchi (whole cabbage kimchi). There’s no stuffing involved, just sliced cucumbers tossed gently with seasoning. It highlights cucumber’s natural crunch and makes this kimchi easy to prepare, even on a busy summer afternoon.

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How to Keep Cucumber Kimchi from Getting Mushy

While the recipe is simple, cucumber kimchi can easily turn soft if a few key steps are skipped. Here’s how to avoid that:

✅ Tip 1: Use Fresh Cucumbers

Always start with very fresh cucumbers. In Korea, we use a variety called oi : thin, crunchy, and low in seeds. Outside Korea, I recommend small pickling cucumbers, mini snack cucumbers, or young regular cucumbers that are crisp and slim. Check the stem end: if it looks dry or wrinkled, it’s likely too old.

✅ Tip 2: Blanch with Boiling Water

Pour boiling water over the cucumbers and immediately rinse in cold water. This quick blanching step helps kill off any surface enzymes or bacteria that could cause softening later.

✅ Tip 3: Trim the Blossom End

Cut off the blossom (flower) end of each cucumber. This part contains enzymes that can cause the entire batch to soften during fermentation.

These three simple steps make all the difference!

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Traditional vs. Global Ingredients

Traditional Ingredient	Common Substitute	Notes
Korean cucumber (oi)	Pickling cucumber, snack cucumber, or young regular cucumber	Look for ones that are firm, crisp, and low in seeds
Asian garlic chives	Chives or fine green onion	Thin green onion stalks give a similar flavor and texture
Korean anchovy sauce (Myeolchi-aekjeot)	fish sauce	For vegan, use a combination of guk-ganjang (Korean light soy sauce) and sea salt

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Key Features of This Recipe

• No flour slurry or porridge: rice syrup is used to kickstart fermentation naturally

• Only 30 minutes of brining, no rinsing

• Naturally fizzy and ready in just a few days

• Small-batch friendly: ideal for 1 kg of cucumbers

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Oi Kimchi (Cucumber Kimchi) Recipe

Makes around 1.5 liters (1.6 quarts) of cucumber kimchi
For this, prepare a kimchi container (preferably airtight glass, ceramic or BPA-free plastic) around 1.7 liters (or 1.8 quarts) by volume.

Ingredients

• 1 kg cucumbers (small pickling, snack, or young regular cucumbers)
  : Use small pickling cucumbers, snack cucumbers, or young regular cucumbers. In Korea, thin-skinned oi are used. Outside Korea, choose firm, fresh cucumbers with minimal seeds for the best crunch and clean fermentation.

• 1½ tbsp (20g) sea salt
  : Used to draw out moisture and begin the fermentation process. I recommend mineral-rich sea salt (like Korean 천일염 or French sel gris) for deeper flavor and microbial support.

• ½ cup (120 ml) water
  : Helps dissolve the salt evenly and ensures even brining without being too aggressive.

• ½ onion, chopped
  : Adds subtle sweetness and depth. Yellow or white both work well. For crisper and milder texture, use sweet onion.

• 50g chives or fine green onion
  : Traditionally, Asian garlic chives (부추, buchu) are used in summer, but they’re hard to find outside Korea. Chives or fine green onions make a great substitute and add a mild bite and freshness.
  

Seasoning (Yangnyeom)

• 4 tbsp gochugaru (Korean chili powder)
  : Gives color, aroma, and a gentle warmth. Use coarse gochugaru for better texture and appearance. Avoid smoked or overly spicy varieties.

• 2 ½ tbsp anchovy sauce (myeolchi-aekjeot)
  : Anchovy fish sauce adds umami and supports fermentation. If you prefer a lighter flavor, use 1½ tbsp anchovy + ½ tsp salt.
  For vegan substitute, use 1½ tbsp guk-ganjang (Korean light soy sauce) + ½ tsp sea salt. This combination mimics the depth and salinity of anchovy sauce, and it’s the same ratio I use for vegan cabbage kimchi. It keeps the kimchi bright and well-seasoned while remaining fully plant-based.

• 1 tbsp rice syrup
  : Naturally sweetens and supports fermentation, replacing the need for a flour slurry. In traditional kimchi, a flour-based porridge is often used to feed lactic acid bacteria, but in this simpler version, rice syrup provides just enough natural sugar to jumpstart the process without altering the texture.

• 1 tbsp (15g) minced garlic
  : A must for authentic kimchi flavor, which also aids fermentation. Adds spice and savory depth

• ½ tsp (3g) minced ginger
  : Adds brightness and balance to the garlic. A little goes a long way.

Finishing

• ½ cup water
  : to get every bit of seasoning from the bowl used to mix kimchi. Pour it into the kimchi container.

Instructions

Step 1: Blanch & Prep the Cucumbers

Bring 1 liter of water to a boil. Place the cucumbers in a colander and pour ½ liter of boiling water over them. Turn them over and pour the rest ½ liter of boiling water over. Shock with cold water and rinse immediately until the cucumbers cool down.

Trim both ends of the cucumber, especially the flower end. If using large cucumbers, quarter lengthwise and remove the seeds with a spoon or knife. Slice into 2–3 cm half-moons.

Step 2: Brine

Transfer cucumbers to a bowl. Dissolve 1½ tbsp sea salt in ½ cup water. Toss and let brine for 30 minutes, flipping halfway. Then drain well for 10 minutes (do not rinse). Shake off excess brine. This preserves the cucumber’s natural sweetness.

Step 3: Prepare the Vegetables

While cucumbers are draining, dice the onion and cut the chives or green onion into 2–3 cm lengths. Halve the white part lengthwise before cutting.

Step 4: Mix & Pack

In a bowl, add drained cucumbers and combine gochugaru, anchovy sauce, rice syrup, garlic, and ginger. Toss them together until cucumbers are evenly coated with the seasoning. Add the onion and chives and toss gently.

Pack into a container and press down lightly. Pour ½ cup of water into the bowl and wash to collect every bit of seasoning left in the bowl, and pour it into the container. It’s okay if not all cucumbers are submerged, they’ll release more liquid overnight.

Step 5: Ferment & Store

Leave the container at room temperature for 12–24 hours (longer if you’re not making this in summer, when room temperatures are lower than 15°C (59°F)) until bubbles start to form and it smells lightly tangy. Then transfer to the refrigerator.

Best after 3–5 days in the fridge. For peak fizz and flavor, enjoy within 2 weeks. Consume within 3–4 weeks for best texture.

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Serving & Storage Tips

• Always serve chilled for the best crunch and flavor

• Perfect with cold noodles, warm rice, or simple grilled dishes

• Keeps up to 1 month, but best enjoyed within the first 2 weeks

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How to Make Your Own Noodles with Cucumber Kimchi

Here is my recipe for Bibim Guksu (spicy cold noodles) that goes perfect with cucumber kimchi. Just serve the noodles with the kimchi, mix, and enjoy!

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FAQs on Cucumber Kimchi

• Can I make this vegan?
  Yes! Simply skip the anchovy sauce and use use 1½ tbsp guk-ganjang (Korean light soy sauce) + ½ tsp sea salt instead. If you have vegan fish sauce, that works too.

• Why don’t you rinse after brining?
  To keep the cucumber’s natural sweetness and ensure enough flavor remains, I skip rinsing and just drain.

• What if my kimchi still turns mushy?
  Double-check freshness, blanching technique, and blossom-end trimming. Older cucumbers or skipping any of those steps can cause softening.

• Is this spicy?
  It’s mildly spiced. Gochugaru gives aroma and color more than heat, but you can reduce the amount or use milder gochugaru if you want it milder.

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Final Notes

Oi Kimchi is one of those kimchi recipes that’s light, quick, but so delicious especially when the weather’s warm. Whether you make it once as a summer fermentation project or keep a small batch in your fridge all season long, it’s a simple way to bring Korean fermentation into your everyday meals 🙂

Let me know if you try it, or if you find your own favorite way to enjoy it. I always love hearing how these recipes find their way into your kitchen!