You know one kimchi. Korea counts them in the hundreds.

Ask someone outside Korea to picture kimchi and you get one image: red, spicy, napa cabbage, in a jar. That is 배추김치 (baechu-kimchi), and it is genuinely the most eaten kind. It is also one item from a very long list, and — this is the part that surprises people — it is a recent arrival.

I work in food R&D in Korea, which means I think about kimchi as a fermentation process rather than a product. From that angle the word does not describe a dish at all. It describes a method: salt a vegetable, season it, and let lactic acid bacteria take over. Apply that to a different vegetable and you have a different kimchi. Korea has been applying it to everything in reach for a very long time.

Two facts that rearrange the whole picture

1. Kimchi was not red until about 250 years ago

Chilli is a New World crop. It reached Korea in the early 1600s, and the first Korean mention of it is in the 1614 encyclopaedia Jibong yuseol. It was not welcomed: for a decade or so it was treated as a poisonous plant and grown as an ornamental.

It took another century and a half to reach the kimchi jar. The 1766 agricultural manual Jeungbo sallim gyeongje is where you can see chilli being used in kimchi, and the middle of the 18th century is when chilli, other spices and 젓갈 (fermented seafood) start appearing together in the form we would recognise.

So for most of its history kimchi was not red. It was white, or clear, or brine-coloured. Preservation came from salt, and shelf life was stretched with plants we no longer associate with food at all: Sichuan pepper, water pepper, pasque flower, and 형개 — a herb still used in Korean medicine.

2. The cabbage is newer than the recipe

The tightly-headed napa cabbage that kimchi is made from today — 결구배추 — is not an ancient Korean vegetable. Through the Joseon period the cabbage grown around Seoul and Kaesong was a loose, half-heading type, smaller and slower growing, and it was expensive enough that it was not what ordinary households packed away for winter.

The modern heading cabbage spread nationally in the 20th century, after an agricultural research station was set up in 1906 and better varieties were imported and bred. The cabbage in your kimchi has roughly a hundred years of history in Korea.

Before that, the default kimchi vegetable was radish. Which means the dish foreigners think of as the original is made with a recent cabbage, seasoned with a spice that arrived from the Americas, in a style perfected in the last couple of centuries.

So what makes something kimchi?

Three steps, and the vegetable is the least fixed part.

1. Salt it. Salting draws water out of the vegetable by osmosis and makes the environment hostile to spoilage organisms while leaving lactic acid bacteria comfortable. This is the step that decides everything downstream.
2. Season it. Chilli, garlic, ginger, spring onion, and usually 젓갈 — salted fermented seafood — which brings both flavour and enzymes.
3. Let it ferment. Leuconostoc species lead early, producing carbon dioxide and a clean sourness; Lactobacillus takes over as acidity rises. pH falls from around 6 to below 4.5, and it keeps falling in the fridge, which is why a jar tastes different in week six than in week one.

Nothing in that list says cabbage. It does not even say chilli.

How many have you actually met?

Why there are so many

Three forces multiply the list.

Season

Kimchi was a preservation system before it was a flavour. Each season has its vegetable and its style: light, fresh, barely-fermented kinds in spring and summer; the big salted winter batch in late autumn. The summer kimchi you eat with cold noodles is not a lesser version of winter kimchi — it is built for a different job.

Region

The pattern runs with the climate. Warmer southern provinces salted harder and used more 젓갈, because things spoil faster there — Jeolla kimchi is the boldest and most savoury. Cooler northern regions used less salt and more liquid, producing milder, wetter kimchi. Seoul sits in between and is the cleanest-tasting. Coastal regions put whatever the boats brought in.

Household

And then every family has its own. UNESCO inscribed kimjang — the communal late-autumn kimchi-making — on the Representative List of the Intangible Cultural Heritage of Humanity in December 2013, and the citation is specific about this: the method and proportions are family heritage, passed down rather than written down. That alone generates variety faster than anyone can catalogue it.

What to do with this

If the only kimchi you have eaten is the red cabbage kind from a jar, the two most worthwhile next steps are the two that are least like it:

• 동치미, for the shock of realising kimchi can be a cold, clear, faintly fizzy drink as much as a side dish.
• 파김치, because spring onion kimchi with grilled pork is the combination that converts people.

And if you find a jar labelled 묵은지 and it tastes aggressively sour, it is not spoiled. It is finished. Put it in a stew with pork and you will understand why Koreans keep some for years.

Sources

Variety counts and regional classification from the World Institute of Kimchi's kimchi content platform. Chilli chronology from Korean food-history sources citing Jibong yuseol (1614) and Jeungbo sallim gyeongje (1766). Napa cabbage introduction from the National Culture Encyclopaedia on heading cabbage replacing traditional varieties. Kimjang inscription from UNESCO decision 8.COM 8.23, December 2013. Fermentation description is my own.