Fermenting with spices
Also called lacto-fermentation, kimchi-making, sauerkraut-making
Quick answer
Letting salted vegetables sour through lactic acid fermentation with spices in the mix — kimchi, sauerkraut, fermented chilli pastes.
What it does to spices
Spices in a vegetable ferment are exposed for weeks to a liquid that grows steadily more acidic, and the ones that belong there are those that survive it and meet the sourness rather than being buried by it: gochugaru and ginger in kimchi, juniper, caraway and dill seed in sauerkraut. The spices do not drive the fermentation, which is the work of lactic acid bacteria feeding on the vegetables’ sugars under salt, but they shape what the finished ferment tastes of, and the combination often tastes more integrated after weeks than it did at the start.
Why it works
Salt draws water and sugars from the vegetable and suppresses spoilage organisms, while salt-tolerant lactic acid bacteria convert the sugars to lactic acid, lowering the pH until the vegetable is preserved. Spice aroma diffuses into the brine over the whole period; capsaicin and most aroma compounds are stable at the acidity reached.
How it goes wrong
- Too little salt, which lets spoilage organisms outpace the lactic acid bacteria.
- Adding delicate fresh herbs whose aroma fades long before the ferment is ready.
Spices it matters for
Where it is used
The pairings that specifically call for this technique.
- Ginger with gochugaru — Both go into kimchi paste raw and in quantity. Ginger’s sharp warmth sits underneath gochugaru’s fruitiness rather than beside it, and the combination survives weeks of fermentation better than either does alone.
- Juniper with cabbage — Sauerkraut and choucroute, where juniper is close to definitional. Fermented cabbage is sour, sulphurous and assertive, and juniper is one of very few spices that meets it rather than being buried by it.
- Dill seed with cabbage — A Northern and Eastern European standing pair, and it is really a pairing with fermentation as much as with the vegetable. Cabbage is sulphurous and, once soured, sharply acidic; the carvone in dill seed cuts through both and adds a warmth that keeps a plate of sauerkraut or braised cabbage from reading as merely sour.
- Kimchi yangnyeom with cabbage — Whole cabbage kimchi, the commonest kind, is made by mixing salted Chinese cabbage with the paste and leaving it to ferment. The cabbage is bland and watery after salting, and everything that makes the kimchi hot, red and savoury comes from the paste.
Questions this page answers
- spices for fermenting vegetables
- spices in sauerkraut
- spices in kimchi