How do I make kimchi at home?

The salting stage that makes or breaks it, the paste, and the two to five days at room temperature before it goes in the fridge.

Difficulty: intermediate
Time: 1 hr
Read: 4 min
Safety: caution

Short answer

Salt chopped Chinese leaf for two hours until a thick stem bends without snapping, rinse and drain well, then mix through a paste of gochugaru, garlic, ginger and something savoury. Pack it down hard in a jar under its own liquid, leave it at room temperature for two to five days until it tastes sour and fizzes, then refrigerate.

Kimchi is a salted, spiced lacto-ferment, and the part that people get wrong is almost always the first stage rather than the interesting one. The salting draws water out of the leaves so they stay crisp and so the ferment has the right concentration — get that wrong and no amount of good paste rescues it.

Safety

Kimchi must stay under its own liquid while fermenting, and the jar must be able to vent — it is a vigorous ferment and a sealed jar can build significant pressure. Judge it by smell and appearance, never by tasting to check safety, and throw away the whole jar if there is any fuzzy growth.

What you'll need

Chinese leaf (napa cabbage), or white cabbage and radish
Coarse pure salt without additives
Gochugaru — Korean chilli flakes
Garlic, ginger, spring onions
Fish sauce, or miso and soy for a vegan version (optional)
A large jar and a fermentation weight

Step by step

Cut the cabbage into large pieces.Quarter it lengthways and cut across into 4 to 5cm pieces, keeping some of the core so the pieces hold together. Larger pieces stay crisper than fine shreds.
Salt it and wait two hours.Layer the pieces in a big bowl with coarse salt between the layers, roughly 40g per kilogram, turning every half hour. It will wilt and release a great deal of water. This is the critical stage.
Test it by bending a stem.Take a thick white stem piece and bend it. It should flex right over without snapping. If it still snaps, give it another half hour. Under-salted cabbage makes watery kimchi that goes soft.
Rinse thoroughly and drain properly.Two or three changes of cold water to take the surface salt off, then drain in a colander for at least twenty minutes. Wet cabbage dilutes the paste and the ferment.
Make the paste.Gochugaru, plenty of crushed garlic, grated ginger, spring onions and either fish sauce or a vegan savoury base of miso and soy. A spoonful of cooked rice or a little sugar gives the bacteria something easy to start on. Use gochugaru rather than ordinary chilli powder — the colour and mildness are not the same.
Mix it through with gloves on.Chilli and garlic under the fingernails last for a day. Work the paste into every piece so nothing is bare.
Pack it down hard into a jar.Press each handful down so the liquid rises over the top. Leave 4 to 5cm of headspace — kimchi is a vigorous ferment and it rises. Stand the jar on a plate.
Ferment at room temperature for two to five days.Press the contents back under the liquid once a day with a clean spoon, and let gas out if the lid is on. It is ready when it smells sour and tangy, bubbles rise when you press it, and the flavour has gone from raw to pickled.
Refrigerate and let it carry on slowly.In the fridge it keeps fermenting very gently for months, getting sourer and softer. Kimchi at three months is a different and arguably better ingredient than kimchi at three days.

Tips

Older, sourer kimchi is what you want for cooking — kimchi jjigae, kimchi fried rice, kimchi pancakes. Fresh kimchi is for eating as it is.
Add mooli or daikon radish, carrot batons and Asian pear for a more traditional result. Anything watery should be salted alongside the cabbage.
Vegan kimchi works well with miso, soy and a little kelp for the savoury depth that fish sauce would otherwise provide.
Open the jar over the sink after the first week. It fizzes.

Common mistakes

Rushing or skipping the salting stage — Salting draws water out of the cabbage. Without it the pieces release their water into the jar during fermentation, diluting everything, and the kimchi ends up watery, bland and soft.
Using ordinary chilli powder instead of gochugaru — Gochugaru is comparatively mild, fruity and vividly red. Cayenne or hot chilli powder makes something far too hot and the wrong colour, and it is the difference between kimchi and spicy cabbage.

If it doesn't work

Kimchi watery and pale

Cause: Not salted long enough, or not drained — Fix: Not recoverable in this batch — use it in cooking. Salt for the full two hours and drain properly next time.

Too sour to eat raw

Cause: Fermented longer, or kept warm — Fix: Not a fault. Use it in stew, fried rice or pancakes, where sourness is what you want.

White film on the surface

Cause: Kahm yeast from air contact — Fix: Skim, press everything under the liquid, refrigerate sooner.

Fuzzy or coloured growth

Cause: Mould — Fix: Bin the whole jar without tasting.

Questions people ask

How long does home-made kimchi keep?

Months in the fridge — commonly three to six, and often longer. It keeps souring the whole time, so it moves from a side dish to a cooking ingredient rather than going off. Keep the contents pressed under the liquid and always use a clean utensil.

Can I make kimchi without fish sauce?

Yes. Replace it with light miso, soy sauce and a piece of kelp, or with a vegan fish sauce. The ferment behaves the same way — the fish sauce is flavour and salt, not the culture.