Lacto-Fermentation and Salt: Why Salt Matters in Kimchi

Lacto-fermentation needs surprisingly little: vegetables, salt and time. Salt is the quiet gatekeeper that makes the whole thing work, from a jar of kimchi to a bottle of tibicos.

Salt, the gatekeeper of lacto-fermentation

In lacto-fermentation, salt sets the terms. It creates an environment where the microbes you want, lactic acid bacteria such as Lactobacillus, can thrive, while unwanted ones are held back. That is how vegetables left at room temperature become sour, tangy and alive instead of spoiled.

What salt does in kimchi

In kimchi, salt draws the water out of the cabbage and vegetables and creates a brine. That brine preserves the crunch, keeps unwanted bacteria out, and gives the lactic acid bacteria room to turn the vegetables' natural sugars into lactic acid, which is where the signature tang comes from. For our kimchi, we work with a salt level of around 2 to 3%.

What salt does in tibicos

In tibicos (water kefir), salt has a different job. The grains like a mineral-rich environment, and a small pinch of salt gives them the minerals they need to grow and ferment well. Use too little and the grains struggle, and the drink comes out weak and flat.

Which salt to use for fermentation

Reach for a natural, unrefined salt, such as sea salt or rock salt. Ordinary table salt often contains anti-caking agents and added iodine, which many fermenters prefer to avoid because they can cloud the brine and may slow fermentation down.

We use mineral-rich Alpine salt from the Salines de Bex, here in Vaud. Visiting the mines was a reminder that every ingredient earns its place, salt included.

What happens with too little salt

Too little salt and unwanted microbes can move in and spoil the batch. Too much and the lactic acid bacteria slow right down. Salt here is not just seasoning, it is part of the safety system. When in doubt, follow a tested recipe rather than eyeballing it.

Salt looks like the simplest thing in the jar. It is quietly doing some of the most important work.