Kimchi (Napa Cabbage Kimchi)

Variations

• The salting is half the recipe, and it is a dewatering device rather than seasoning. Fermentation basics reduces pickling to three levers and the first is salt concentration. Salt draws the water out of the cabbage's cells by osmosis (salt and seasoning), and that water becomes the brine the kimchi ferments in. No water is ever poured in.
• Which is why three pickles here split three ways over one question: where the brine comes from. Kimchi makes its own; paocai pours one into the jar and keeps it alive for years; takuan uses no liquid at all and buries the radish in dry rice bran.
• Stems that bend without snapping is the doneness test for the salting. Under-salted, the cabbage gives up its water later and thins the paste. Over-salted, the salt suppresses the lactic bacteria along with everything else and it never turns sour — only salty.
• The rice porridge is not only glue. Lactic bacteria live on sugar and cabbage has little free sugar to offer. Gelatinised starch lays that food down in advance, and it suspends the gochugaru at the same time. Two jobs, not one.
• Geotjeori: fresh, unfermented — dress the salted cabbage and eat it straight away.
• Baek-kimchi: white kimchi made without chilli, clean and cooling.
• Vegan kimchi: skip the seafood and build savour with soy, doenjang or shiitake stock.
• Chonggak / kkakdugi: the same paste on whole young radishes or diced radish. Oi-sobagi scores a cucumber and stuffs it.

Tips

• Brining is 80% of it — not too salty, not under-salted; the stems should bend, not snap.
• The rice porridge helps the paste cling to the cabbage and aids fermentation.
• Fermented seafood (salted shrimp, fish sauce) is the key to umami — sub kelp/shiitake for vegan.
• Leave it at room temp 1-2 days to kick off fermentation, then chill for deeper flavour.
• Wear gloves, and press out the air in the container.
• Pressing the air out is an anti-mould measure, not a preference. It is the same guide's third lever, and its answer is to press everything under the liquid. Cabbage standing proud of the brine is where mould starts.
• Souring slows down; it never stops. The falling pH eventually inhibits the bacteria that caused it, but fermentation continues even in a fridge — which is why a dedicated kimchi fridge holds close to 0°C, and why sour kimchi goes into kimchi jjigae, kimchi fried rice and kimchijeon. Heat pushes that sourness into the background.