Salt is the one measurement in a vegetable ferment that you can’t fix later. Too little and the ferment is more likely to go soft
or off; too much and it barely ferments. Enter your weight and percentage below to get the salt in grams. Pick a vegetable to fill in
the method and salt level our recipes use.
Dry Salting or Brine: What the Percentage Means
Recipes write “2% salt” for two different things, and mixing them up is the most common reason a ferment ends up with half or
twice the salt it should have.
- In dry salting (sauerkraut, shredded or chopped vegetables, salsa bases), the salt is a percentage of everything
in the jar, aromatics included. 1 kg of cabbage at 2% takes 20 g of salt. The salt draws water out of the vegetables and makes its
own brine. NCHFP’s recipe, 3 tablespoons of canning salt for each 5 pounds of cabbage, works out to a little over 2%
(NCHFP). - In a brine (whole or cut vegetables covered with salt water, such as carrots, beans or cucumbers), the salt is a percentage of
the water. A litre of water weighs 1 kg, so a 2% brine is 20 g of salt in 1 litre of water.
A brine percentage describes the water, not the finished jar. Once the salt evens out between the brine and the vegetables, the
jar ends up less salty than the brine you poured: 500 g of water at 3% (15 g of salt) over 600 g of carrots settles at roughly 1.3% of
everything in the jar. Enter the vegetable weight in brine mode to see that figure. That’s normal, and it’s why brine recipes call for
2–3% or more.
For the salt level, method and time for 23 vegetables, see the table in our guide to the best vegetables to ferment.
Cucumbers are the exception: NCHFP’s dill pickles use a much stronger brine (½ cup of canning salt and ¼ cup of 5% vinegar for 8 cups
of water, about 7–8% of the water by weight; NCHFP), which our fermented dill pickles follow. Olives are cured stronger still, at 6% and then 12% of the water: see how to brine-cure olives.
Why Weigh Salt Instead of Using Spoons
A level teaspoon of fine table or canning salt weighs about 6 g, but coarse kosher salt and flaked salts weigh much less per
spoon, and brands differ from each other. NCHFP says flake salt “varies in density” and recommends against it for fermenting for that
reason (NCHFP). A kitchen scale that reads single grams costs less than a crock and removes the guesswork; the
calculator shows a teaspoon estimate only as a cross-check.
Which Salt to Use
- Canning or pickling salt is the standard: pure, fine and consistent (NCHFP).
- Table salt, iodized or not, is safe for fermented pickles; its anti-caking agents can make the brine cloudy
(NCHFP). In a sauerkraut study, iodized salt made no significant difference to the bacteria
(Müller et al., 2018). - Sea salt and kosher salt work if they’re pure salt; weigh them, because their density varies.
- Reduced-sodium salts (potassium blends such as “Lite Salt”) are not for fermented pickles (NCHFP).
How Much Salt Is Enough?
For cabbage, 2–2.5% of the weight is the established range. Commercial sauerkraut is made with 2.0–2.25% salt, and in natural (no
starter) cabbage ferments at 0.5% and 1%, texture and flavour became highly variable, with softening and off-flavours as the salt went
down (Johanningsmeier et al., 2007). What a starter culture changes, and why it doesn’t replace salt, is in starter cultures or whey for vegetables. In a study of spontaneously fermented northeast Chinese sauerkraut at 0.5, 1.5, 2.5
and 3.5% salt, 2.5% gave the most lactic acid bacteria, the fastest drop in pH and the best-rated flavour
(Yang et al., 2020). NCHFP is blunt about the low end: salt “is vital to safety and texture”, so don’t make sauerkraut or
fermented pickles by cutting back on it (NCHFP).
More salt isn’t safer, just slower: fermentation takes longer and the result is saltier. Most vegetable ferments on this site use
2–3%; stay inside the range the recipe gives.
Temperature and Time
Salt and temperature work together. For sauerkraut, NCHFP recommends 70–75°F (21–24°C), where it is fully fermented in about 3–4
weeks; at 60–65°F (16–18°C) it takes 5–6 weeks; below 60°F it may not ferment, and above 75°F it may go soft
(NCHFP). Fermented dill pickles also take 3–4 weeks at 70–75°F and soften above 80°F
(NCHFP). Short brined vegetables such as carrots are ready in days rather than weeks.
For what’s going on in the jar, see the science of fermentation. For the temperature and time each ferment needs, see the fermentation temperature chart.
What the Calculator Can’t Check
- Let it finish. In sauerkraut deliberately contaminated with E. coli O157:H7 and Listeria, both
survived in the brine for most of the fermentation and were undetectable only at the end (15 days for shredded cabbage, 28 for whole
heads) (Niksic et al., 2005). Eat a ferment once it is properly sour, not while it is still getting there. - Keep everything under the brine with a weight, and use clean jars and hands.
- Learn to tell mould from kahm yeast. A flat white film is usually harmless kahm yeast; fuzzy or coloured mould means the
batch goes. See the fermentation troubleshooting guide. - Refrigerate it when it tastes right, and see how to store fermented foods for how long it keeps.
New to all of this? Start with one of the easiest first ferments, or with classic
sauerkraut, which needs only cabbage and salt.