Kalguksu Recipe: Learn How to Make Kalguksu Noodle Soup

Kalguksu is a traditional Korean noodle soup. Chefs cut kalguksu noodles with a knife instead of stretching or extruding them, and the name “kalguksu” translates to “knife noodles” in English. The cooked noodles are added to a soup based on seafood, vegetable, or chicken broth, and most recipes include vegetables such as zucchini and potatoes.

Many Koreans eat kalguksu in the summer, and there are numerous regional variations. Bajirak kalguksu is a seafood noodle soup that includes littleneck clams, while haemul kalguksu features a broader range of seafood and shellfish like prawns and octopus. Some kalguksu recipes include additional protein-rich ingredients such as snails, pheasant, or beans. Modern Korean kalguksu recipes sometimes incorporate kimchi or kimchi juice into the stock to add extra sourness.

Historians trace kalguksu's origins back to the Goryeo period in ancient Korea between 918 AD and 1392 AD. Noodles were an expensive luxury and reserved for the upper classes during this period. Written descriptions of noodle soup recipes like kalguksu remained vague until 1670 during the Joseon era, when Lady Jang Gye-Hyang wrote the first known kalguksu recipe in her recipe book Eumsik Dimibang.

Noodles remained an expensive commodity until 1953. Ordinary people generally only consumed them on special occasions, such as celebrating a new child's birth. In 1953, the Korean War ended, and the supply of wheat from overseas combined with a more robust economy made noodles affordable for the general population for the first time. Today, kalguksu is a staple Korean street food.

Kalguksu noodles are usually made from wheat flour mixed into a dough with eggs. The dough is then rolled out on a flat surface into a thin rectangle and sliced into ribbons with a knife. Some kalguksu recipes include dried bean powder or mashed mung beans in the noodle dough to give them a firmer texture. Adding mugwort to the noodle dough provides a herby, slightly bitter flavor.

You can purchase pre-made dried kalguksu noodles from specialist Asian food stores instead of making them from scratch. You can also use ramen or udon noodles as substitutes if you can't find authentic kalguksu noodles, although the texture will be somewhat different.

It’s easy to adapt kalguksu to your own schedule and dietary needs.

1. 1. Make the broth in advance. You can make the noodle broth in advance if you want to make your kalguksu quickly at mealtime. However, don't add the noodles to the broth until you're ready to eat. Cooked kalguksu noodles are highly absorbent and will soak up the broth and turn soggy unless you eat them right away.
2. 2. Substitute salt and dried kelp for soy sauce. This recipe uses soy sauce to give the broth a salty, savory flavor. However, you can season the broth with extra salt if you don't have soy sauce to hand. Consider adding some dried kelp for extra saltiness and an umami taste.
3. 3. Substitute vegetable stock for fish stock. Most kalguksu recipes are unsuitable for vegetarians because they use seafood stock. However, you can make a plant-based noodle dish by substituting fish stock for vegetable stock or bouillon. You may need to season the soup with extra salt or soy sauce to achieve a similar umami taste. You can also use chicken stock to create a chicken noodle soup called dak kalguksu, which has a meatier flavor.
4. 4. Add a variety of toppings. Adding different toppings to your kalguksu can turn it into a more substantial meal and customize it to your taste. Shredded chicken, cooked beef mince, and stir-fried shiitake mushrooms are popular kalgusku toppings.