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Korean Fermented Foods: A Guide to Jang and Kimchi

한국의 발효 음식

Korea has one of the world's most sophisticated fermentation traditions. Here is a guide to the essential fermented ingredients in Korean cooking.

Korea's Fermentation Culture

Korea has one of the world's most sophisticated and long-standing fermentation traditions. Fermented foods are not a trend or a health fad in Korea — they are the foundation of the entire cuisine. The three "jang" (장 — fermented soybean products), kimchi, and various jeotgal (fermented seafood) are present in virtually every Korean meal.

The Three Jang

Ganjang (간장 — soy sauce): The liquid byproduct of doenjang production. Korean soy sauce has a more complex flavor than industrially produced soy sauce. Doenjang (된장 — soybean paste): The solid byproduct of ganjang production. Bold, pungent, and deeply umami. Gochujang (고추장 — chili paste): Made by adding gochugaru to a base of doenjang and glutinous rice. Spicy, sweet, and fermented. All three are made from the same meju (fermented soybean brick) base, then diverge in flavor based on additional ingredients and aging time.

Kimchi Fermentation

Kimchi fermentation is driven by naturally occurring Lactobacillus bacteria found on cabbage and other vegetables. When cabbage is salted, its cell walls break down and release sugars that feed the lactobacillus. As the bacteria ferment these sugars, they produce lactic acid, which preserves the kimchi and creates its characteristic sour flavor. Fresh kimchi is sweet and slightly funky; older kimchi develops deep sourness and complexity.

Jeotgal: Fermented Seafood

Less internationally known but equally important is jeotgal (젓갈) — the category of fermented and salted seafood used both as condiments and as kimchi-making ingredients. The most common are saewoo jeot (새우젓 — salted shrimp) and aekjeot (액젓 — fish sauce, typically anchovy). These add the savory umami depth to kimchi and soups that makes them taste so complex. Eating jeotgal directly as banchan — like salty, intensely flavored small bites — is a traditional Korean practice.

Frequently Asked Questions

What are the main fermented foods in Korean cooking?

The three essential fermented soybean pastes are gochujang (fermented chili paste), doenjang (fermented soybean paste), and ganjang (soy sauce). Together they are called "jang" (장). Beyond jang, kimchi is Korea's most famous fermented food, and there are also fermented seafood condiments (jeotgal, 젓갈) like salted shrimp and fish sauce.

What is jang in Korean cooking?

Jang (장) is the collective term for Korea's essential fermented soybean condiments: gochujang (red chili paste), doenjang (soybean paste), and ganjang (soy sauce). These three form the flavor backbone of Korean cuisine in the same way that fish sauce, soy sauce, and shrimp paste do in Southeast Asian cooking.