Fermented Flatfish with Millet

Sikhae (식해, 食醢) is fish fermented with salt and cooked grain. It is easily confused with sikhye (식혜), the sweet rice-and-malt drink — the names differ by a single vowel, and both use cooked grain softened by malt — but sikhae is a savory, chili-red side dish of fish. The Encyclopedia of Korean Folk Culture explains its place on the coast: the west, with plenty of sea salt, developed heavily salted jeotgal, while the east, where salt was scarcer, combined a lighter salting with the lactic fermentation of grain. As the grain ferments it sours, and the acid protects the fish and gives sikhae its tang.

Fish sikhae appears in Korean records from the 15th century: the cookbook Sanga yorok (c. 1450) describes salted fish packed into a crock between layers of cooked rice. Gajami-sikhae, made with flatfish (gajami), is the best-known example today and is above all a dish of Hamgyeong Province, on the far northeast coast. The Encyclopedia of Korean Culture describes it as a preserved food that makes good use of the clear-water flatfish of the East Sea and the millet of the north, and notes that adding malt (yeotgireum) to the millet sets the Hamgyeong version apart, since the malt sugars the grain's starch.

According to the folk encyclopedia, it reached South Korea with refugees from Hamgyeong during the Korean War, and today it is made along the Gangwon coast north of Gangneung, including the Sokcho area. Other East Sea communities make sikhae with cooked rice instead of millet, and on the east coast a version without chili was traditionally placed on ancestral-rite tables. Before refrigeration it was put down at kimjang time and eaten over a short season; now it is made year round.

• Calcium from the bones: the fish is eaten bones and all, softened by fermentation; in the database figures a 40 g serving supplies about 120 mg of calcium.
• Lactic fermentation: a study of gajami-sikhae fermented at 5–20°C found lactic acid bacteria such as Latilactobacillus sakei, Lactiplantibacillus plantarum and Leuconostoc species dominating, and concluded that cool temperatures make for the best fermentation. Whether these bacteria benefit health is still being researched.
• Less salty than many jeotgal: at about 685 mg sodium per 100 g in the database, it carries well under half the sodium of most salt-cured jeotgal, because the grain ferment does part of the preserving.

• Hamgyeong: the defining style — small flatfish salted and pressed, then fermented with cooked foxtail millet, malt powder, garlic, ginger and chili, with salted radish strips folded in at the end.
• Gangwon coast: carried south by Hamgyeong refugees; the fish is often semi-dried before mixing and the batch ripens for two weeks or more.
• Other East Sea sikhae: cooked rice instead of millet, and other fish such as pollock, mackerel, sandfish and anchovy.
• For ancestral rites: east-coast households traditionally made a chili-free version for the ritual table.