Yeolmu Kimchi (Quick-Fermented Young Radish Greens) Recipe

What Is Yeolmu Kimchi?

One of my favorite summer kimchis, called yeolmu kimchi, is made with young, crunchy radish greens—usually with their tiny radish roots still attached. This is a quick kimchi that’s ready to eat in just a few days, with the help of a starchy porridge to speed up the fermentation.

This kimchi brings back memories from my childhood, when I lived with my grandmother in Gangwon Province, north of Seoul. Our house had a courtyard, and in the summertime, we liked to open the doors and put a small table down with a view of the outdoors and our garden full of eggplant, chiles, cucumbers, and perilla leaves. Korean summers are humid and sticky, but we’d play outside, sweaty and happy. When my grandmother and mother called us home for lunch, they’d often serve up bowls of cold noodles topped with crunchy, cooling yeolmu kimchi.

The Role of Kimchi in Korean Cuisine

Kimchi is special to us Koreans. Traditionally, it played an important role in the Korean diet by preserving vegetables during the hot summers and freezing-cold winters. Even though we have refrigeration today, we love kimchi for its funk, fragrance, and flavor. It’s sour, salty, sweet, bitter, and savory all at once, pairing well with meats and adding variety to any meal.

We consider kimchi to be good for our health, and there are even Koreans who pack it when traveling abroad. With over 200 kinds of kimchi, we’ll have at least one type in our fridge at all times, usually something seasonal and often something well-aged. It really depends on personal preference—some Koreans love the fresh, bright flavors of new kimchi, and others love the deeper, more mellow flavors of aged kimchi.

Uses for Yeolmu Kimchi

Yeolmu kimchi can be eaten fresh, as soon as a day after it's made, though I prefer the flavors you get after about a week. If you make a mild version, without fish sauce or the extra gochugaru (Korean red chile flakes), it’s nice as a banchan (side dish) with spicy, meaty foods.

If you make your yeolmu kimchi with the fish sauce and extra gochugaru, it’s great for barley bibimbap: Start with pressed barley (found at Korean grocery stores), soak for 30 minutes with your rice (using a 1:1 ratio), and cook as you’d normally cook rice. Top the bowl of warm barley rice with a generous ladleful of kimchi.

The spicy version of yeolmu kimchi is also good with cold noodles: Boil some somyun (thin wheat noodles), chill, and top with cold, clear beef broth and yeolmu kimchi. Garnish with a thin slice of cooked beef and a boiled egg sliced in half lengthwise, and pour in some kimchi juice.

And if you have any yeolmu kimchi left after a few months and it’s getting old, don’t toss it out! Use it for kimchi fried rice, sautés, or seafood braises. Every Korean grandma knows a hundred ways of using old kimchi, and trust me, you don’t want to waste good flavor.

Pul and the Fermentation Process

Keep in mind that this is a quick ferment: Yeolmu kimchi uses pul (풀), a starchy porridge for kimchi, to speed up the fermentation process. In all kimchi, as with other preserved vegetables like sauerkraut and dill pickles, naturally occurring lactobacillus bacteria consume the vegetable sugars, producing lactic acid (preserving the vegetables) and CO2 (giving us bubbles...and, if your container is sealed too tight, sometimes explosions). The starchy pul not only balances out the greens’ grassy flavors, but also gives the lactobacillus a megadose of carbohydrates to chow down on and really get the fermentation started.

The exact amount of pul you use isn’t important, and when you're making kimchi for long-term storage, it isn’t even necessary. (Given enough time, the vegetables have more than enough sugars for a full fermentation.) But for quick fermentations like this one, the pul helps speed up the process. Any kind of starch, such as glutinous rice flour or all-purpose flour, can be used to make the porridge, but I prefer a basic white potato simply simmered in water, then blended into a slurry.

The radish greens (yeolmu) bring a wee bit of peppery kick, and the young cabbage greens, eolgari baechu (얼갈이 배추), also sold as put-baechu (풋배추), add a nice contrasting sweetness. I use a 1:1 ratio of radish to cabbage greens, but you can go with an all-radish version for more pungency.

This kimchi is easily adaptable to your taste. With the optional additions of salted shrimp, fish sauce, and gochugaru, you can make these radishes as funky and spicy as you like.

How to Make Yeolmu Kimchi

Step 1: Make a Porridge (Pul)

For seasonal, quickly consumed kimchi recipes like this one, I start by making the pul (풀), or porridge. You can use any kind of potato you have, but waxy potatoes tend to boil and blend down into a stickier porridge, making the mixing a much gummier process. Your choice of potato, however, won’t affect the flavor. Russets are a good choice, as are basic white potatoes.

Step 2: Prep and Salt the Greens

When I prep the greens, I split any thick radish roots in half or even quarters lengthwise, so they ferment evenly along with the little guys. I handle the greens as minimally as possible and avoid salad spinners, which run the risk of bruising their tender leaves and releasing too much grassy flavor. Anyhow, they don’t have to dry perfectly; kimchi is a wet preparation, and there's more water on the way! After you wash and drain your greens, it’s time to salt them.

I salt the greens in a large bowl, with coarse sea salt if possible. Fine salt penetrates too quickly, making it difficult to control the seasoning.

Salting vegetables for kimchi is often a matter of personal taste, but a rough estimate would put the typical final salinity at around 3 to 5%. For the vegetables, the general idea is to add enough salt to wilt the vegetables at room temperature in about an hour or two—maybe roughly a good handful per layer of greens (or around 15% salt by weight; don't worry, you'll rinse most of this salt off after wilting the greens).

When they're ready, your wilted greens shouldn’t be stiff, but should instead bend easily when you hold a piece up. I recommend rinsing one piece to taste it—it should taste pleasantly salty. If you didn’t get it quite right in this step, you’ll be able to compensate later with your brine.

Now it's time to rinse the wilted greens of excess salt and drain them well.

Step 3: Add Flavorings

For the base of my seasoning, I roughly chop fresh red chiles and stir them into a paste of onion, garlic, ginger, and the cooled porridge (pul). When I want a more refreshing summer kimchi, I’ll stop here. The optional salted shrimp (saewoojeot) and fish sauce add umami and salt, but many prefer the clean and sharp taste of kimchi without them. If you’re feeling funky, go for it—it’s up to you!

Step 4: Cover With Brine

The trick in this recipe is to use a basic saltwater brine to balance out the overall saltiness of the kimchi and create a good environment for the lactobacillus to thrive, ultimately arriving, as mentioned above, at a salinity of about 3 to 5%. If my chile paste mixture isn't salty enough, this is where I can add more salt. And vice versa—if I made my mixture too salty (don’t forget, shrimp paste and fish sauce add salt!), I’ll make a milder brine here. You can compensate for oversalted greens with the brine, too.

The salt is important not just for flavor but also for tipping the scales in favor of friendly lactobacillus. Most nasty food bacteria don't do well in salty environments, but lactobacillus does.

Most importantly, don't stress too much, since you have some latitude here in terms of the salt level. While you can calculate it all by weight, it's just as easy to do it by taste. Remember, you want the overall saltiness of the kimchi to be somewhere in the zone of ocean water, which is a bit saltier than what most of us consider to be the "perfect" level of seasoning in the food we eat.

To finish my kimchi prep, I place the rinsed and drained greens in a large container and cover them with the onion and chili paste, along with the pul (if using). Then I pour the brine in on top of that, making sure it's enough to fully cover all the solid ingredients.

Don’t forget to keep your kimchi away from air. All the vegetables should be fully submerged in the brine; use a plate, fermentation weight, or a layer of plastic wrap pressed against the surface to keep the air off the greens. Lactobacillus do their work with anaerobic fermentation, so just remember: Kimchi hates air!

Keep it out on the counter for a day, or until you just start to smell that funky fermentation starting up, then store it in the fridge. After about a week, the kimchi should be ready to eat.