Water Kimchi (Mul Kimchi): The Refreshing, Mild Korean Fermented Classic
Water kimchi, known in Korean as mul kimchi (물김치), is a lightly fermented, brine-based kimchi that is as much a drinking broth as it is a side dish. Unlike the fiery, red-pepper-coated traditional baechu kimchi most people know, water kimchi is mild, subtly tangy, and beautifully refreshing — making it the perfect entry point for beginners and a beloved staple for anyone who wants a gentler fermented food in their diet.
Perfect for Beginners
Water kimchi is one of the easiest fermented foods you can make at home. It requires no gochugaru (Korean red pepper flakes), uses simple ingredients, and ferments quickly — often ready to enjoy in just 1–3 days at room temperature.
What Is Water Kimchi?
Water kimchi is a mul (water) based kimchi where vegetables are submerged in a seasoned, lightly salted brine and allowed to ferment naturally. The result is a crisp, lightly effervescent, slightly sour liquid packed with vegetables that can be sipped as a cooling drink or eaten as a refreshing banchan (side dish).
Historically, mul kimchi was especially popular during the hot Korean summer months as a way to cool down and replenish electrolytes. It is also traditionally served to children, the elderly, and people who cannot tolerate spicy food.
Key characteristics of water kimchi:
- Mild and refreshing flavor — no heat or chili
- Light, slightly tangy and effervescent brine
- Crisp vegetables (radish, cucumber, napa cabbage, or a combination)
- Quick fermentation time (1–3 days at room temperature)
- Naturally vegan and gluten-free
Key Ingredients You'll Need
One of the joys of water kimchi is its simplicity. You don't need a long list of specialty items to get started.
Core Ingredients:
- Napa cabbage or Korean radish (mu) — the most traditional vegetable bases; daikon radish also works wonderfully
- Water — use filtered or unchlorinated water for the best fermentation results
- Non-iodized salt — sea salt or kosher salt; iodized salt can inhibit beneficial bacteria
- Garlic — thinly sliced or lightly crushed for flavor and fermentation activity
- Ginger — a small knob adds warmth and depth without heat
- Green onions — for brightness and color
- Asian pear or apple — optional but traditional; adds natural sweetness and aids fermentation
- Rice flour paste — a small amount thickens the brine slightly and feeds the good bacteria
Optional Add-ins:
- Thinly sliced carrots for color and crunch
- Sliced cucumber for extra freshness
- Dried jujubes (Korean dates) for a subtle sweetness
- Pine nuts as a traditional garnish
Why Use Rice Flour Paste?
A small amount of cooked rice flour paste (1–2 teaspoons per liter of brine) provides simple sugars that feed the Lactobacillus bacteria responsible for fermentation. It also gives the brine a slightly silkier texture. You can skip it, but it does speed up and enrich the fermentation process.
How to Make Water Kimchi: Step-by-Step
Step 1: Prepare and Salt Your Vegetables
Cut your main vegetable — typically Korean radish or napa cabbage — into bite-sized cubes or strips approximately 2–3 cm in size. Lightly salt the vegetables (about 1–2% salt by weight) and let them sit for 30–60 minutes to draw out excess moisture. Rinse lightly and drain.
Step 2: Make the Brine
Combine the following in a large bowl or jar:
- 1 liter of filtered water
- 1 teaspoon non-iodized sea salt (adjust to taste — brine should be mildly salty, like a light soup)
- 1 teaspoon cooked rice flour paste (optional)
- 1 teaspoon sugar or a few slices of Asian pear
Stir well until the salt is fully dissolved.
Step 3: Add the Aromatics
Add to the brine:
- 3–4 cloves of garlic, thinly sliced
- 3–4 thin slices of fresh ginger
- 2–3 green onions, cut into 3 cm pieces
- A few slices of Asian pear or apple (optional)
Step 4: Pack the Jar
Place your drained vegetables into a clean glass jar. Pour the seasoned brine over the vegetables, making sure everything is fully submerged. Leave at least 2–3 cm of headspace at the top of the jar to allow for the natural gases produced during fermentation.
Step 5: Ferment
Cover the jar loosely — do not seal it airtight, as CO₂ needs to escape. Leave at room temperature (ideally 18–22°C / 65–72°F) for 1 to 3 days, tasting daily.
- Day 1: Brine is fresh and only slightly salty
- Day 2: Light tanginess begins; gentle bubbles may appear
- Day 3: Noticeably sour and lightly effervescent — this is often the sweet spot
Once it reaches your preferred level of sourness, move it to the refrigerator to slow fermentation.
Step 6: Serve and Enjoy
Serve water kimchi chilled, ladling both the vegetables and a generous amount of the brine into a small bowl. Garnish with a few pine nuts if desired. Sip the brine like a light soup or enjoy the vegetables as a refreshing side dish alongside rice and other Korean dishes.
Watch Your Fermentation Temperature
Warmer kitchens (above 25°C / 77°F) will cause water kimchi to ferment much faster and can quickly become overly sour or develop off-flavors. In hot weather, start tasting your kimchi after just 12–18 hours and refrigerate earlier than you think you need to.
Tips for the Best Water Kimchi
- Use the freshest vegetables possible — since water kimchi is mild and light, the quality of your vegetables really shines through
- Always keep vegetables submerged — exposure to air can lead to mold; use a small zip-lock bag filled with brine as a weight if needed
- Taste as you go — fermentation is a living process; your ideal flavor is the best guide
- Save some brine — leftover brine from a previous batch is an excellent starter (like a mother culture) that will accelerate your next batch
- Clean equipment matters — ensure jars and utensils are clean, though not necessarily sterilized; residual soap can inhibit fermentation
Variations to Try
Once you've mastered the basic recipe, explore these popular variations:
- Oi Mul Kimchi — made with cucumbers; ultra-refreshing in summer
- Baechu Mul Kimchi — uses whole or quartered napa cabbage leaves as the base
- Nabak Kimchi — a classic version using a combination of radish squares and napa cabbage; often tinted pale pink with a small amount of gochugaru or red pepper for color only, not heat
Frequently Asked Questions
How long does water kimchi last in the refrigerator? Water kimchi keeps well in the refrigerator for up to 2–3 weeks. It will continue to slowly ferment and become more sour over time, which many people enjoy. The brine itself is delicious even after the vegetables have been eaten.
Can I make water kimchi without garlic? Yes, though garlic contributes significantly to both flavor and fermentation activity. If you need to omit it due to dietary preferences, increase the amount of ginger slightly and consider adding a small piece of onion to compensate for some of the flavor complexity.
Is water kimchi good for gut health? Absolutely. Like all naturally fermented foods, water kimchi is rich in Lactobacillus bacteria — the same beneficial probiotic strains found in yogurt and traditional kimchi. The brine is especially rich in live cultures and is a great way to consume probiotics in a light, digestible form.
Why does my water kimchi brine look cloudy? Cloudiness in the brine is completely normal and is a sign of active, healthy fermentation. It is caused by the proliferation of beneficial Lactobacillus bacteria. As long as there is no pink or black mold on the surface and the smell is pleasantly sour (not putrid), your water kimchi is perfectly safe and delicious.
Related Tools
Related Guides
- Traditional Kimchi Guide
- Kkakdugi (Radish Kimchi) Guide
- Beginner's Guide to Lacto-Fermentation
- How to Choose the Right Salt for Fermentation
Disclaimer
This content is for educational purposes only and is not medical advice. Fermented foods affect individuals differently. Consult with a healthcare provider before making significant dietary changes, especially if you have health conditions. Practice proper food safety when fermenting at home.