Korean kimchi tofu soup is a spicy, tangy stew of ripe kimchi, soft tofu, and a savory broth, often served bubbling hot with rice. This flexible home-style version builds flavor by sautéing the kimchi first, then simmers it with gochugaru and vegetable broth for a satisfying meal in about 40 minutes.
Ingredients
- 1 tablespoon (15 ml) neutral oil, such as canola or vegetable oil
- 1 medium yellow onion, thinly sliced (about 1 cup or 150 g)
- 3 garlic cloves, finely chopped (about 1 tablespoon or 9 g)
- 2 cups (300 g) well-fermented napa cabbage kimchi, cut into bite-size pieces
- ¼ cup (60 ml) kimchi brine, taken from the jar
- 2 teaspoons (10 ml) toasted sesame oil
- 2 tablespoons (12 g) gochugaru, Korean red pepper flakes; use 1 tablespoon (6 g) for a milder broth
- 1 tablespoon (18 g) gochujang, Korean chili paste
- 4 cups (960 ml) low-sodium vegetable broth
- 1 tablespoon (15 ml) soy sauce
- 1 teaspoon (4 g) granulated sugar, optional, to balance especially sour kimchi
- 1 package (16 ounces or 450 g) soft or silken tofu, drained gently
- 2 green onions, thinly sliced (about 30 g)
- ¼ teaspoon (1.5 g) fine salt, plus more as needed
- 1 teaspoon (3 g) toasted sesame seeds, optional
- 3 cups (about 480 g) cooked short- or medium-grain rice, for serving
Instructions
- Prepare the ingredients. Slice the onion, chop the garlic, cut the kimchi into manageable pieces, and slice the green onions. Drain the tofu carefully; soft tofu breaks easily, so there is no need to press it. Measure out the broth, kimchi brine, and seasonings before you begin cooking. This small amount of preparation helps the soup come together smoothly once the pot is hot.
- Build the kimchi base. Heat the neutral oil in a medium heavy pot or Dutch oven over medium heat. Add the onion and cook for 3 minutes, stirring now and then, until it begins to soften. Stir in the garlic and kimchi and cook for 2 minutes. Add the sesame oil and gochugaru, then stir for about 30 seconds so the pepper flakes bloom in the oil. Keep the heat moderate; scorching the garlic or pepper can make the broth taste bitter.
- Simmer the broth. Stir in the gochujang, kimchi brine, vegetable broth, soy sauce, and optional sugar. Bring the liquid to a gentle boil, then lower the heat and simmer uncovered for 15 minutes. Stir once or twice, making sure the kimchi stays mostly submerged. The broth should taste lively and savory, while the cabbage softens but still has some texture. If it reduces more than you like, add a splash of water or broth.
- Add the tofu. Taste the broth before adding salt, since kimchi, brine, broth, and soy sauce can all contribute saltiness. Add the measured salt only if needed. Break the tofu into large spoonfuls directly over the pot, or cut it into generous cubes if you prefer neater pieces. Fold it in gently rather than stirring vigorously. Simmer for 4 minutes, just until the tofu is hot all the way through.
- Finish and serve. Stir in most of the green onions, then turn off the heat. Ladle the soup into bowls and top with the remaining green onions and sesame seeds, if using. Serve immediately with warm rice. For a table-style meal, keep the rice in a separate bowl so each person can add as much as they like.
Tips
- Choose kimchi with some age. Well-fermented kimchi gives the broth its characteristic sour depth. Fresh, mild kimchi still works, but the soup will taste less tangy; a little extra kimchi brine or a few drops of rice vinegar can sharpen it. Taste before adding extra salt or acid.
- Adjust the heat in stages. Gochugaru varies in heat, and gochujang adds both spice and sweetness. Begin with 1 tablespoon (6 g) of gochugaru if you are unsure, then taste the simmering broth and add more if you want a stronger chili flavor. Do not substitute ordinary crushed red pepper in the same amount; it is often hotter and lacks gochugaru’s rounded, fruity flavor.
- Handle soft tofu gently. Silken and soft tofu create a tender, custardy texture that suits this style of soup. Medium-firm tofu is a practical substitute if that is what you have; it holds its shape better and makes the stew less delicate. Avoid pressing soft tofu, which can break it up before it reaches the pot.
- Use low-sodium broth and season last. Kimchi and its brine can be quite salty, and their salt levels vary by jar. Low-sodium vegetable broth gives you more control. If the finished soup tastes too salty, add a little hot water or unsalted broth rather than trying to cover the salt with extra chili paste.
Serving Suggestions
Serve the soup hot alongside freshly cooked short- or medium-grain rice, which is easy to spoon into the spicy broth. A small bowl of rice per person is a useful starting point, but rice portions are personal, so it can be served separately. For a fuller Korean-inspired spread, add simple side dishes such as cucumber salad, seasoned spinach, roasted seaweed, or lightly dressed bean sprouts. Keep the sides mild and crisp if you want contrast with the soft tofu and deeply flavored soup.
For a casual meal, bring the pot to the table and ladle the soup into individual bowls, taking care to include tofu and kimchi in each serving. A little extra sliced green onion adds freshness, while sesame seeds give a subtle nutty finish. If serving the soup in a very hot stone or earthenware bowl, handle it with oven mitts and set it on a heatproof trivet. The broth is best enjoyed hot, but let it settle briefly before eating so you can taste the balance of sour, savory, and spicy flavors.
Variations
Make it vegan. The recipe as written is vegan when the kimchi is made without fish sauce or salted seafood. Some traditional kimchi contains seafood ingredients, so check the label if needed. If you have homemade kimchi, its ingredients will determine whether the soup is fully plant-based.
Use anchovy broth. In Korean cooking, anchovy-kelp stock is a common alternative to vegetable broth and gives the soup a more traditional savory backbone. Replace the 4 cups (960 ml) of vegetable broth with the same amount of prepared anchovy-kelp broth. For a quick pantry version, vegetable broth is convenient, though its flavor is less distinctly seafood-savory.
Add mushrooms or vegetables. Add 1 cup (70 g) sliced shiitake or cremini mushrooms with the onion, or stir in a handful of spinach during the final minute. Mushrooms deepen the savory flavor, while spinach softens quickly and adds color. Avoid adding a large amount of watery vegetables without reducing the broth slightly, or the soup may taste diluted.
Make it milder or richer. Reduce the gochugaru and gochujang for a gentler soup, keeping in mind that gochujang also adds sweetness and body. For a richer variation, stir in ½ cup (120 ml) unsweetened soy milk or a spoonful of tahini near the end; this is not a traditional flavor, but it makes the broth creamier and less sharp. Add either gradually and taste as you go.
Storage and Reheating
Refrigerate leftover soup within 2 hours of cooking in a covered, shallow container. It keeps for 3 to 4 days in the refrigerator. The tofu may become a little softer as it sits, and the kimchi flavor can grow more pronounced, but both are normal. If possible, store rice separately so it does not soak up the broth and become overly soft.
Reheat only the portion you plan to eat, either in a saucepan over medium-low heat or in a microwave-safe bowl. Stir gently and heat until steaming throughout; avoid a vigorous boil, which can break up the tofu. USDA FSIS recommends reheating leftovers to 165°F (74°C); check the temperature with a food thermometer if you need to verify it. If the broth has thickened in the refrigerator, add a tablespoon or two of water or broth while reheating. Discard soup that has been left at room temperature for more than 2 hours, or more than 1 hour in temperatures above 90°F (32°C).
For longer storage, freeze the cooled soup in a freezer-safe container for up to 2 months for best quality. Leave a little space at the top for expansion. Thaw it overnight in the refrigerator and reheat as described above. Soft tofu can turn more porous and slightly spongy after freezing, so the texture will not be quite as custardy as when freshly made; the broth remains useful for a quick meal.
Frequently Asked Questions
Is Korean kimchi tofu soup the same as sundubu jjigae?
Not always. Sundubu jjigae commonly features very soft tofu in a spicy Korean stew, and kimchi may be included, but there are many versions with different broths and additions. This recipe combines kimchi and soft tofu in a home-style soup; recipes vary by household and region, so there is no single version that covers every bowl.
Can I use firm tofu instead of soft tofu?
Yes. Firm tofu is easier to cut and stir without breaking, but it will give the soup a chewier, less delicate texture. Add it in cubes during the final 4 to 5 minutes so it heats through and takes on some of the broth’s flavor. If using extra-firm tofu, consider smaller cubes so each piece is pleasant to eat with a spoon.
What can I use if I cannot find gochugaru?
Gochugaru is Korean red pepper powder or flakes, and it has a distinctive mild-to-moderate heat with a rounded flavor. If it is unavailable, use a smaller amount of crushed red pepper flakes, starting with about ½ teaspoon and adjusting to taste. This substitute will usually taste sharper and hotter, so it will not give exactly the same color or flavor. Sweet paprika can add color but will not replace the chili heat.
How do I make the soup less sour?
Use less kimchi brine, choose kimchi that is not extremely fermented, and add the optional teaspoon of sugar to balance the acidity. A little additional broth can also soften a strongly sour taste. Avoid adding a large amount of sugar, which can make the soup taste sweet rather than balanced; adjust in small amounts and taste after each change.
Can I make the soup ahead?
Yes. You can prepare the kimchi broth through the 15-minute simmer, cool it promptly, and refrigerate it for up to 3 to 4 days. Reheat the broth, then add the tofu and cook until hot before serving; this preserves more of the tofu’s soft texture. If the broth tastes more concentrated after chilling, loosen it with a little water or unsalted broth.