Fermentation is not a trend in Korea — it is the foundation of the entire cuisine. From kimchi to doenjang to jeotgal, fermented foods define the flavour of Korean cooking. Here is how they work and why they matter.
Fermentation: The Heart of Korean Cooking
Korea's relationship with fermentation stretches back thousands of years. Before refrigeration, before canning, fermenting was the way to preserve vegetables through harsh winters and to transform simple ingredients into complex, deeply flavoured foods. What makes Korean fermentation distinctive is its scale and diversity — there are estimated to be over a hundred different types of kimchi alone, each with regional variations. Fermentation in Korea is not a technique; it is a philosophy.
Kimchi: Beyond the Basics
Most people in the UK know kimchi as spicy fermented cabbage, and that is accurate as far as it goes. But baechu-kimchi (napa cabbage kimchi) is just the most common variety. There is also kkakdugi (cubed radish kimchi), oi-sobagi (stuffed cucumber kimchi), pa-kimchi (spring onion kimchi), and dozens more. The fermentation process involves salting the vegetables, coating them in a paste of gochugaru, garlic, ginger, fish sauce, and often rice flour paste, then packing them tightly and leaving them to ferment. The lactobacillus bacteria naturally present do the rest, producing lactic acid that gives kimchi its characteristic sour tang.
The Jang Trio
Korea's three essential fermented pastes — ganjang (soy sauce), doenjang (soybean paste), and gochujang (chilli paste) — are collectively known as jang. Traditionally, all three begin with meju, blocks of fermented soybeans that are hung to dry and colonised by beneficial moulds. The meju is then soaked in brine, and the liquid that separates becomes ganjang while the solids become doenjang. Gochujang adds glutinous rice powder and gochugaru to the fermented soybean base. This interconnected process means the three jang share a family of flavours while each contributing something unique.
Cheonggukjang: The Intense One
Cheonggukjang is Korea's most pungent fermented food — a fast-fermented soybean paste that takes only two to three days (compared to months for doenjang). The smell is... assertive. It is often compared to strong blue cheese, and it is one of those foods where the gap between smell and taste is enormous — the flavour in soups is deeply savoury and warming. Cheonggukjang-jjigae is a Korean comfort food classic, though it is best cooked with the windows open. Sempio's version is the most accessible for UK buyers.
Health and Science
Korean fermented foods are genuinely good for gut health — this is not just marketing. The lactobacillus bacteria in kimchi are well-researched probiotics. Doenjang contains isoflavones and has been the subject of studies linking it to lower rates of certain cancers in Korean populations. The fermentation process also breaks down nutrients into more bioavailable forms and generates B vitamins. There is a reason Korea has one of the longest life expectancies in the world, and diet — specifically fermented foods — is widely considered a contributing factor.
Getting Started with Fermentation
You do not need to start making your own kimchi to benefit from Korean fermentation (though it is a rewarding project). Simply incorporating shop-bought kimchi, doenjang, and gochujang into your regular cooking introduces a range of fermented flavours and associated health benefits. Keep them in the fridge, use them regularly, and let your palate adjust. The funk grows on you — most people who start eating Korean fermented foods find it difficult to stop.
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Korean Fermented Foods: A Complete Guide
Why fermentation is central to Korean cuisine and what you need to know.
You do not need to start making your own kimchi to benefit from Korean fermentation (though it is a rewarding project). Simply incorporating shop-bought kimchi, doenjang, and gochujang into your regular cooking introduces a range of fermented flavours and associated health benefits. Keep them in the fridge, use them regularly, and let your palate adjust. The funk grows on you — most people who start eating Korean fermented foods find it difficult to stop.
Korean fermented foods are genuinely good for gut health — this is not just marketing. The lactobacillus bacteria in kimchi are well-researched probiotics. Doenjang contains isoflavones and has been the subject of studies linking it to lower rates of certain cancers in Korean populations. The fermentation process also breaks down nutrients into more bioavailable forms and generates B vitamins. There is a reason Korea has one of the longest life expectancies in the world, and diet — specifically fermented foods — is widely considered a contributing factor.
Cheonggukjang is Korea's most pungent fermented food — a fast-fermented soybean paste that takes only two to three days (compared to months for doenjang). The smell is... assertive. It is often compared to strong blue cheese, and it is one of those foods where the gap between smell and taste is enormous — the flavour in soups is deeply savoury and warming. Cheonggukjang-jjigae is a Korean comfort food classic, though it is best cooked with the windows open. Sempio's version is the most accessible for UK buyers.
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The Jang Trio
Korea's three essential fermented pastes — ganjang (soy sauce), doenjang (soybean paste), and gochujang (chilli paste) — are collectively known as jang. Traditionally, all three begin with meju, blocks of fermented soybeans that are hung to dry and colonised by beneficial moulds. The meju is then soaked in brine, and the liquid that separates becomes ganjang while the solids become doenjang. Gochujang adds glutinous rice powder and gochugaru to the fermented soybean base. This interconnected process means the three jang share a family of flavours while each contributing something unique.
02
Kimchi: Beyond the Basics
Most people in the UK know kimchi as spicy fermented cabbage, and that is accurate as far as it goes. But baechu-kimchi (napa cabbage kimchi) is just the most common variety. There is also kkakdugi (cubed radish kimchi), oi-sobagi (stuffed cucumber kimchi), pa-kimchi (spring onion kimchi), and dozens more. The fermentation process involves salting the vegetables, coating them in a paste of gochugaru, garlic, ginger, fish sauce, and often rice flour paste, then packing them tightly and leaving them to ferment. The lactobacillus bacteria naturally present do the rest, producing lactic acid that gives kimchi its characteristic sour tang.
01
Fermentation: The Heart of Korean Cooking
Korea's relationship with fermentation stretches back thousands of years. Before refrigeration, before canning, fermenting was the way to preserve vegetables through harsh winters and to transform simple ingredients into complex, deeply flavoured foods. What makes Korean fermentation distinctive is its scale and diversity — there are estimated to be over a hundred different types of kimchi alone, each with regional variations. Fermentation in Korea is not a technique; it is a philosophy.