Gejang (marinated crab) has long been beloved by Koreans. Sallim Gyeongje (Farm Management), a book written by Hong Man-seon during the late Joseon period, provides detailed recipes for gejang. Hong describes two methods: one using soy sauce and the other using salt.

Compared to the famous soy sauce version, sogeumgejang (salt marinated crab) is lesser known and can be unfamiliar for some. The salt in sogeumgejang draws out moisture from the crab meat, giving it a firmer, chewier texture than ganjanggejang. Although sogeumgejang has become a rarity, some fishers in certain areas still make it as a delicacy.

Korea is home to various types of crabs, all found in different regions. In the eastern coast, you can find snow crabs, red snow crabs, and horsehair crabs, while the western and southern coasts are rich in blue crabs, Asian paddle crabs (also known as bakhaji or dolge), and helmet crabs. Blue crabs are particularly abundant along the entire west coast, making it a regional specialty. Yeonpyeongdo Island in Incheon stands out as a major source, accounting for 8% of the total catch in Korea. Valued for their nutritional benefits and rich flavor, blue crabs are most commonly prepared as ganjanggejang in Korean cuisine.

Blue crabs are in season twice a year: during the spring when they feed heavily to prepare for spawning and the fall when they fatten up for the winter. Common wisdom suggests that female crabs are best in the spring and males in the fall; however, this can be somewhat misleading. Spring is indeed when female crabs are at their peak, as they are full of eggs ready to be fertilized. Male crabs, on the other hand, are known to be at their best in the fall as they fatten up to endure the winter. While this is true, it doesn’t mean that female crabs are any less flavorful during this season, as both accumulate comparable levels of nutrients in their bodies.

The key ingredient in ganjanggejang is the soy sauce, as using traditionally crafted soy sauce gives the dish a richer, more savory flavor. Ganjanggejang using traditional soy sauce is made through the following process.

First, soybeans are formed into meju (a fermented soybean block), which is then processed into soybean paste and fermented again. Once fermented, the soy sauce is separated from the paste—a process Koreans call “splitting the sauce.” Both the soybean paste and soy sauce take on deeper flavors as they age.

Next, the soy sauce is boiled with ingredients such as onion, chili pepper, kelp, and ginger, allowing their flavors to infuse into the sauce. After cooling the sauce, the washed blue crab is added and marinated for two to four days, making it ready to enjoy.

Ganjanggejang made with traditional soy sauce command significantly higher prices than those made with commercial soy sauce, and their flavors most certainly reflect this quality.

There are two steps involved in enjoying ganjanggejang. First, add a spoonful or two of steamed rice to the crab's carapace and mix it with the yellow intestines. Then, take a spoonful of this rice mixture to enjoy the sweet, savory, and salty flavors of the gejang.

Next, move on to the meat inside the body. Hold a piece of the pincer with your fingers and press your thumb against one side to push out the meat and, if the crab is female, the eggs. You can add a spoonful of soy sauce for an extra layer of flavor.

For those who enjoy spicy food, yangnyeomgejang (spicy marinated crab) is another excellent choice. This dish is prepared by tossing blue crabs in a sauce made from chili pepper powder, minced garlic, ginger, soy sauce, and black pepper. Unlike ganjanggejang, yangnyeomgejang uses fresh blue crabs, offering a fresher, plumper flavor with spicy, tender meat. Wearing disposable plastic gloves, press down on the yangnyeomgejang to extract the flesh, then mix it with steamed rice and sauce for an elevated experience.

Gejang has long been a staple of home-cooked meals in Incheon, leading many renowned traditional ganjanggejang restaurants to be located in the city’s residential areas rather than tourist spots. Some of these restaurants use traditionally made soy sauce, while others opt for commercially produced soy sauce. Although the dish using the former tends to be more expensive, ganjanggejang in Incheon is generally more affordable than in other regions.

Some restaurants offer all-you-can-eat ganjanggejang for 20,000 to 30,000 KRW per person. However, these places often use smaller blue crabs and store-bought soy sauce.