What Is Kimchi? A Complete Guide to Korea's Fermented Staple

6 hours ago

3 min read

What is kimchi? Kimchi is a Korean dish of salted, seasoned vegetables, usually napa cabbage or radish, that are left to ferment until they turn crunchy, tangy and deeply savoury. It is Korea's everyday side dish, and the ferment we make most often at Ragi in Lutry.

In one sentence: kimchi is vegetables preserved by lactic acid fermentation, flavoured with chilli, garlic and ginger, and eaten raw, at every stage from fresh to very sour.

Where kimchi comes from

Kimchi has been part of Korean food for centuries. Each late autumn, families and neighbours gather for kimjang, the collective making of enough kimchi to last through winter. UNESCO added kimjang to its list of the Intangible Cultural Heritage of Humanity in 2013 (UNESCO).

There isn't one kimchi but hundreds: whole cabbage kimchi (baechu kimchi), cubed radish kimchi (kkakdugi), cucumber kimchi, water kimchi without chilli, and countless family recipes.

How kimchi is made

Salting. The cabbage is salted or soaked in brine for several hours. Salt draws water out of the leaves, keeps them crunchy and lets the right microbes take over.
Rinsing and draining. The excess salt is washed off.
Seasoning. A paste of chilli flakes, garlic, ginger and onion is rubbed into every leaf. Traditional recipes add salted seafood; ours are 100% vegan and get their umami from organic miso.
Packing. The vegetables are pressed tightly into jars so they sit in their own juice, away from air.
Fermenting. Lactic acid bacteria naturally present on the vegetables turn sugars into lactic acid. The pH drops, the kimchi turns sour, and it is preserved.

Scientists who sequenced the microbes in kimchi found it is dominated by three groups of lactic acid bacteria: Leuconostoc, Lactobacillus and Weissella (Jung et al., 2011). Want to know why salt matters so much? Read lacto-fermentation and salt.

Fresh napa cabbages, the base of most kimchi

What does kimchi taste like?

Fresh kimchi is crunchy, garlicky and mildly spicy, a bit like a punchy salad. As it ferments, it becomes sourer and more complex, with a gentle fizz. Very aged kimchi is strongly sour and perfect for cooking: stews, fried rice, pancakes and soups.

Stage	Taste	Best for
Fresh (first days)	Crunchy, garlicky, mild	Salads, toast, bowls
Ripe (a few weeks)	Tangy, balanced, lightly fizzy	Eating as a side, sandwiches
Aged (several months)	Very sour, soft, intense	Fried rice, soups, stews

Kimchi vs sauerkraut

Both are fermented cabbage, but sauerkraut is usually just cabbage and salt, while kimchi is seasoned with chilli, garlic and ginger and can include many vegetables. We compare them in detail in kimchi vs sauerkraut.

How we make kimchi at Ragi

At Ragi in Lutry, we make kimchi in small batches with organic vegetables, mostly from Switzerland: napa or Savoy cabbage, plus a seasonal ingredient such as parsnip, beetroot, pear or pumpkin seed. We never pasteurise it, so the cultures stay alive, and we never add fish sauce or shrimp.

How to eat kimchi

Straight from the jar as a side dish, on toast with hummus or avocado, in grain bowls, in fried rice, on pizza or in a warming soup. Find more ideas in 10 ways to use kimchi in the kitchen or try our kimchi fried rice with smoky tempeh.

Kimchi FAQ

Is kimchi vegan?

Traditional kimchi often contains fish sauce or salted shrimp. Ours never does: at Ragi, we replace that umami taste with organic miso, so all our kimchi is 100% vegan.

How long does kimchi last?

Our kimchi keeps for 2 years in the fridge. It stays safe to eat, but the longer you keep it, the sourer and softer it gets.

Why is my kimchi fizzy or bubbling?

That's fermentation at work: the bacteria release carbon dioxide. Open the jar over a plate, and keep it in the fridge to slow things down.

Is kimchi always spicy?

No. Most kimchi contains chilli, but the heat varies a lot, and white or water kimchi contain none. At Ragi, our seasonal kimchis are mild, our Spicy Kimchi gets its kick from lemon drop pepper, and our Extra Spicy Kimchi from habanero pepper.