Miyeok Guk (Seaweed Soup)

Sea mustard (miyeok, Undaria pinnatifida) went by many names in old texts, and soup made from it was written gwakgaeng. Its place in Korean life comes from childbirth. The Encyclopedia of Korean Culture describes the custom of serving a new mother white rice and miyeok-guk as her first meal, the cheotguk-bap, made without beef and seasoned only with soy sauce and sesame oil. The seaweed for it was chosen broad and long, bought without haggling, and tied with straw rather than folded — folding it was thought to bring a difficult birth.

Writers in the eighteenth century already treated the practice as distinctly Korean. The Encyclopedia of Korean Folk Culture cites Yi Ik's Seongho saseol calling seaweed a fine remedy for new mothers in the customs of the East, and Yi Gyu-gyeong recording that Chinese people his grandfather met in Beijing in 1778 did not know what dried seaweed was for. Yi Gyu-gyeong also passed on a folk tale about a man swallowed by a whale that had just given birth, who saw its belly lined with seaweed — a story, not a history. Another record describes bowls of rice and miyeok-guk first set out for Samsin, the goddess of childbirth, before the mother ate.

The folk encyclopedia concludes that the postpartum custom probably began in some regions and families and spread nationwide from the late Joseon period. Only in the twentieth century did miyeok-guk become the soup of the birthday table, a link most Koreans now take for granted. Because of the childbirth connection, "eating seaweed soup" also became slang for failing an exam; one theory ties it to the forced 1907 disbanding (haesan) of the Korean army, a homophone of the word for giving birth.

• Sea mustard supplies vitamin K, calcium and fiber, and seaweed is a major source of dietary iodine in Korea.
• The Encyclopedia of Korean Culture links the postpartum custom to the belief that seaweed's iodine helps milk production; this is a traditional explanation rather than an established effect.
• With beef, the soup is a light source of protein that is easy to eat.

• Beef: the standard version, with brisket or shank stir-fried in sesame oil with the seaweed before water goes in, which turns the broth milky.
• Gyeongsang coast: on Geoje Island, flounder (gajami) or dodari is simmered with the seaweed and seasoned with soup soy sauce.
• Jeju and the east coast: Jeju fishing villages use tilefish (okdom); east-coast villages use dried pollock.
• Gyeonggi: some homes add glutinous-rice dumplings (saealsim) to the soup.
• Other broths: chicken stock or dried mussels are traditional alternatives to beef.