Last updated: 2026-07-02

Fermentation Salt Percentage

Lacto-fermentation turns fresh vegetables into sauerkraut, kimchi, and pickles by letting salt-tolerant bacteria produce acids that preserve and flavour the batch. Salt is the lever that makes this work: it draws liquid from the vegetables, favours the right microbes, and holds back spoilage until the acidity builds. The reliable way to set the salt amount is as a percentage of a reference weight, not a fixed pinch or a scoop.

Salt as a percentage of weight

Because a small jar of kraut and a large crock of pickles need salt in proportion to their contents, the amount is best expressed as a fraction of a reference weight:

$\text{salt} = \text{reference weight} \times \text{salt percentage}$

The reference weight depends on the method. For most vegetable ferments a level of about 2% is a dependable starting point, and the common working range is roughly 2% to 3.5%. Lower percentages ferment faster and taste milder; higher ones (up to around 5%) slow things down and suit warmer rooms or longer keeping.

Dry-salting versus brine

There are two ways to introduce the salt, and the calculator handles both.

Dry-salting mixes salt straight into shredded or chopped vegetables. The salt pulls out their own juices, which become the brine in place. This is how sauerkraut and many kimchi styles are made, and the percentage is taken from the vegetable weight — commonly near 2%.

Brine dissolves salt in water and pours it over larger or whole pieces that cannot release enough liquid on their own, such as cucumbers, beans, or peppers. Here the percentage is taken from the water weight, and 3% to 3.5% is typical because the salt has to diffuse into the produce.

Weigh the salt, don't scoop it

Salt is sold in different crystal forms, and they do not fill a spoon the same way. Fine salt is dense, so a level teaspoon holds about 6 grams. Coarse salt is flaky and packs loosely, so the same teaspoon holds only about 4.8 grams. That means a teaspoon of one salt can be noticeably saltier than a teaspoon of another.

The calculator reports grams first, because grams are unambiguous, and then converts to teaspoons and tablespoons for the salt type you pick. Use non-iodised salt without anti-caking agents for the cleanest ferment, and if you have a kitchen scale, weigh the salt and ignore the spoons.

Worked example

For a brine batch, switch the method and enter the water weight instead: a 1 kilogram (about 1 litre) brine at 3.5% needs 35 grams of salt dissolved before pouring over the vegetables. If you switch to coarse salt, the gram figure stays the same but the spoon count rises, because each spoon of coarse salt weighs less — which is exactly why weighing beats scooping.