Kongguksu (Soy Milk Noodle Soup)

Discover the refreshing charm of kongguksu (콩국수), a creamy and nutty Korean noodle dish that’s perfect for cooling down on hot summer days.

In this recipe, I’ll guide you through creating a traditional version of kongguksu, complete with tips on how to incorporate soybean powder and chickpeas as flavorful alternatives to soybeans. Let’s make this beloved Korean classic together and enjoy its best flavor and texture!

Why Make Kongguksu at Home

Kongguksu, also known as Kong-guksu or soy milk noodles, is a creamy, nutty, and savory delight that serves as the perfect antidote to scorching hot days. This refreshing noodle soup not only provides a cool and satisfying escape from the heat but also delivers a powerful nutritional boost.

Rich in plant-based protein and essential nutrients, it provides a light yet filling meal that nourishes and energizes. While many Korean summer noodles are celebrated for their spicy and bold flavors, kongguksu offers a contrasting experience with its mild, calming, and soothing taste, making it an ideal choice for a relaxed and refreshing meal.

Tips for the Best Kongguksu

Soybeans and Alternatives

Consider using organic soybeans for your recipes. Interestingly, I had some trouble finding dried soybeans at my local Korean and non-Korean grocery stores. Fortunately, I was able to order them from Amazon, and they worked perfectly. For kongguksu, you’ll need to soak the soybeans overnight or for at least 8 hours to rehydrate them. However, if you use hot boiling water, 1 hour is sufficient.

If soybeans aren’t your thing, chickpeas are a good substitute, though they have a milder flavor. Personally, I prefer the taste of kongguksu made with soybeans. You can use either dried or canned chickpeas, both of which work well. Canned chickpeas are a great time-saver since they don’t need soaking.

Alternatively, you can use soybean powder (konggaru, 콩가루) from a Korean grocer. Not all Korean grocers carry it, but when they do, it’s often ready to use for kongguksu and may include other ingredients like ground nuts and a bit of salt.

To prepare, mix and dissolve the powder in water or milk. Then, simply serve it over boiled thin wheat noodles like somen (somyeon, 소면) and top with your choice of toppings (see the suggestions in the ingredients section below). I find that using milk gives a richer, nuttier flavor than water, so I recommend it. However, the soybean powder has quite an intense nutty flavor on its own, so I don’t feel the need to use soy milk.

For the best results, use 1/2 cup of soybean powder with 1 cup of full cream milk and 1/4 teaspoon of fine sea salt. Even though the soybean powder already contains salt, you’ll hardly notice it once the noodles are added, so you might want to sprinkle in a little extra.

Soy Milk and Alternatives

There are a couple of ways to make the soup for this recipe, and I think organic soy milk works best when using actual soybeans for a deeper flavor. However, if you don’t have soy milk or prefer not to use it, you can use the water from boiling soybeans or regular milk instead. Just keep in mind that these alternatives won’t be as rich and flavorful as the soy milk version and may give your soup a less appealing look.

Ingredients for Kongguksu

1/2 cup organic dried soybeans (or dried chickpeas, or one 425g can of chickpeas)
5 cups water
3/4 tsp fine sea salt, divided (1/4 tsp for boiling + 1/2 tsp for blending)
1 Tbsp sesame seeds
1 Tbsp pine nuts
1 Tbsp walnuts
200g / 7.1 ounces somen noodles (thin wheat noodles)
2 cup unsweetened organic soy milk, chilled
1 tsp sugar, raw
50g / 1.8 ounces cucumber (Lebanese or English), julienned
1-2 cherry tomatoes, halved
1-2 eggs, boiled, halved

* 1 Tbsp = 15 ml, 1 cup = 250 ml

How to Make Kongguksu

1. Prepare soybeans.

(1) Soak the dry soybeans in some boiled water (100°C / 212°F) for an hour. Alternatively, you can let them sit in room temperature water overnight, or for at least 6-8 hours.

(2) Drain the water and wash the soybeans under running water. Remove any loose shells that come off.
(3) In a pot, mix soybeans with water and 1/4 teaspoon of salt. Boil over medium heat for 15 minutes, skimming off any foam with a spoon. Note: The next three photos show chickpeas.

(4) Reduce the heat to medium-low and boil for another 40-45 minutes until the soybeans are fully cooked.

(5) Rinse the soybeans under running water and remove any remaining shells. Set them aside. 1/2 cup (96g / 3.4 ounces) of dry soybeans will yield approximately 1 cup (183g / 6.5 ounces) after boiling.

While the soybeans are boiling, use this time to get the other ingredients ready.

2. With a mortar and pestle, crush the sesame seeds, pine nuts, and walnuts until they’re finely ground. This hands-on method is key for a smooth texture since these nuts and seeds don’t blend well in a blender, helping them mix perfectly into the soup.

3. Cook the somen noodles in boiling water according to the package instructions, typically for 3-5 minutes. Once cooked, drain the noodles and rinse them under cold running water to cool.

4. Place the prepared soybeans, soy milk, ground nut mixture from step 2, sugar, and 1/2 teaspoon of salt into a blender. Blend everything together until the mixture is smooth and well combined.

5. Transfer the cooked somen to a serving bowl and pour the soy milk mixture generously over the noodles. Garnish with cucumber slices, cherry tomatoes, and a halved boiled egg.