Kimchi and jang Korean fermentation tradition

Korean fermentation is anchored by two complementary pillars: kimchi (lacto-fermented vegetables, most commonly baechu / napa cabbage) and the jang trinity doenjang (soybean paste), ganjang (soy sauce), and gochujang (chile paste). Together, they form the foundational flavor system of Korean cuisine, a tradition codified over centuries and recognized by UNESCO in 2013 when kimjang, the winter kimchi-making ritual, was inscribed as an Intangible Cultural Heritage of Humanity [UNESCO 2013].

Kimjang and onggi

Kimjang is a seasonal community event typically held in late autumn, where extended families and neighbors gather to prepare large quantities of kimchi for winter storage. The process relies on onggi hand-thrown, unglazed earthenware pots with porous walls that allow natural air circulation and temperature regulation, creating an ideal environment for lacto-fermentation. Onggi are also used for aging jang products, with some doenjang and ganjang aged for years in these pots to develop depth.

Meju and the jang trinity

All three jang begin with meju blocks of fermented soybeans that are dried in sunlight for several weeks, then aged in brine. Meju is inoculated with naturally occurring Aspergillus oryzae and Bacillus subtilis molds, which break down proteins into amino acids and starches into sugars. The resulting brine yields ganjang (soy sauce), while the solid residue becomes doenjang (soybean paste). Gochujang is made by mixing meju powder with gochugaru (Korean red chile flakes), glutinous rice starch, and jeotgal (fermented seafood), then aging it in onggi. Unlike Japanese miso (which uses rice or barley koji) or Chinese doubanjiang (which relies on broad beans and Aspergillus), Korean gochujang is distinguished by its use of gochugaru a Mexican-origin chile introduced to Korea in the 16th century via Japan and its sweet-spicy-savory balance from the rice starch fermentation.

Modern industrial vs. traditional homemade

Industrial production dominates the Korean market today, using stainless-steel tanks, pasteurization, and standardized starter cultures to ensure consistency and shelf stability. Traditional homemade kimchi and jang, however, remain culturally prized for their complex, terroir-driven flavors. Artisanal producers and maeul (village) cooperatives continue to use onggi and natural fermentation, often aging doenjang for 1–3 years and ganjang for 3–5 years.

Dietary notes

Most traditional kimchi includes jeotgal (salted fermented shrimp, anchovies, or fish sauce) and is therefore not vegan. Vegan kimchi, made with salt, gochugaru, garlic, ginger, and sometimes jeotgal-free jang, is widely available as an alternative. Doenjang and ganjang are typically vegan, though some commercial varieties may include anchovy or shrimp extract. Gochujang often contains jeotgal; vegan versions exist. All three jang are generally gluten-free (made from soybeans and rice), but cross-contamination is possible in industrial facilities. Kimchi and jang are naturally low in fat and rich in probiotics, vitamins, and minerals.