How much salt for your ferment?

Why the salt percentage matters

In a vegetable ferment, salt does three jobs: it pulls water and sugars out of the vegetables to feed the fermenting bacteria, it favors those lactic acid bacteria over spoilage organisms and harmful bacteria, and it keeps the vegetables crisp. Virginia Cooperative Extension stresses that salt should be measured carefully and a tested recipe followed, because too little lets mold and contaminants grow and too much slows the fermentation. That is why the amount is stated as a percentage, not as a spoon.

The formulas

For salted vegetables such as sauerkraut, salt = weight of the vegetables × percentage ÷ 100. For a brine poured over vegetables, salt = weight of the water × percentage ÷ 100, with one liter of water taken as one kilogram. To check a brine, divide the salt by the water (percent of water) or by water plus salt (percent of the whole brine). The spoon amounts divide the grams by the weight a teaspoon of that salt holds according to its label: 1.5 g per quarter teaspoon for Morton fine salt, 1.2 g for Morton Coarse Kosher and 0.7 g for Diamond Crystal. Those label weights are rounded, so spoon amounts are approximate.

Worked example

You have 5 pounds (2268 g) of shredded cabbage. At 2.5% the salt is 57 g, and at 2.25% it is 51 g. The NCHFP recipe calls for 3 tablespoons of canning salt per 5 pounds; at 18 g a tablespoon that is about 54 g or 2.38%, which agrees with the range. For a quart-sized brine (about 946 g of water), 3% needs 28 g of salt and 5% needs 47 g. That 5% brine is 5% of the water weight but 4.76% of the finished brine; in teaspoons of fine salt it is about 7.9 teaspoons, but about 16.9 teaspoons of Diamond Crystal, which is why weighing beats measuring.

Safety and limits

• Different sources, different numbers. Virginia Cooperative Extension gives 3% to 5% for low-salt pickles, 5% to 16% for high-salt and at least 6% for crisp cucumbers, while the NCHFP dill pickle recipe works out to about 7.6% by our conversion. Pick one tested recipe and follow it; do not average them.
• Do not cut the salt to be healthier. Lower salt favors more kinds of microorganisms and, by Virginia Cooperative Extension, can let mold and other contaminants grow. Reduced-sodium salt is not recommended for pickles.
• pH 4.6 is the safety line. Clemson Extension notes that kraut fermentation, done properly, brings the food to pH 4.6 or below; foods above that line are low-acid and are the ones Clostridium botulinum can make toxin in when sealed. A home cook cannot see the pH, so rely on a tested recipe, a covered container, the right temperature and submerged vegetables.
• Keep everything under the brine. Both Extension sources want the vegetables 1 to 2 inches below the liquid, with the container covered against insects and mold, and soft, slimy or foul-smelling product thrown away.
• Not for canning decisions. If you plan to can fermented vegetables, use the NCHFP processing times and a tested recipe; the salt arithmetic here does not replace them.

How much salt do I need for sauerkraut?

About 2.25% to 2.5% of the cabbage weight, according to Virginia Cooperative Extension and Clemson Extension. For 5 pounds (2268 g) of shredded cabbage that is 51 to 57 g. The NCHFP recipe says 3 tablespoons of canning salt per 5 pounds; with fine salt at about 18 g a tablespoon (the Morton label, 1.5 g per quarter teaspoon) that works out to 2.38%, inside the range. Weigh the cabbage after trimming and coring, and mix the salt in evenly so no part is under-salted.

How much salt goes in a brine for pickles?

Virginia Cooperative Extension gives 3% to 5% salt for low-salt pickle fermentations and 5% to 16% for high-salt ones, and says cucumber fermentations should be at least 6% for good texture. The figure is a percent of the water by weight. A 3% brine for a quart of water (946 g) needs 28 g of salt, and a 5% brine needs 47 g. The NCHFP dill pickle recipe uses ½ cup of salt with 8 cups of water and ¼ cup of 5% vinegar for each gallon of container, which is roughly 7.6% of the water weight. These sources do not agree on one number, so follow a tested recipe for the product you are making.

Is it percent of the water or of the whole brine?

Most fermenting guidance means salt weight over water weight. Salt over the whole brine, water plus salt, is a smaller number: 47 g in a quart of water is 5% of the water but 4.76% of the finished brine. The difference grows with strength, so check which one your recipe means. Our brine calculator for meat shows both side by side.

Why does the type of salt matter?

Two reasons. First, additives: Virginia Cooperative Extension says table salt's anti-caking agents cloud the brine, iodine can darken vegetables and slow fermentation, and sea salt impurities, lime and magnesium can soften or embitter the product; it recommends canning or pickling salt, which has no impurities and a consistent grain, and does not recommend reduced-sodium salt. Second, volume: a teaspoon of coarse kosher salt holds much less salt than a teaspoon of fine salt (by the labels, 0.7 g per quarter teaspoon for Diamond Crystal against 1.5 g for fine table salt). Weighing avoids the problem.

Is fermenting vegetables safe?

Done by a tested recipe it is a long-established method: lactic acid bacteria make acid that keeps harmful bacteria from growing, and salt favors them over spoilage organisms (Virginia Cooperative Extension). Clemson Extension notes that a properly done kraut fermentation brings the food to a safe acidity, pH 4.6 or below, which is the line between acid foods and low-acid foods in canning; above it, Clostridium botulinum spores can germinate in sealed, low-oxygen conditions. The practical rules from the extension sources are: keep the vegetables 1 to 2 inches under the brine, use the salt percentage in a tested recipe, cover the container, keep it at about 68 to 72 °F (Virginia Cooperative Extension; NCHFP says 70 to 75 °F), and discard anything soft, slimy or with a bad smell. If you are unsure, throw it out.

What if the vegetables float above the brine?

Weigh them down so they stay 1 to 2 inches below the liquid. Virginia Cooperative Extension suggests a plate held down by sealed jars of water, or a heavy food bag filled with brine so that a leak does not dilute the batch; its bag brine is 4½ tablespoons of salt per 3 quarts of water. If the juice from the cabbage does not cover it, NCHFP says to add boiled and cooled brine of 1½ tablespoons of salt per quart, which is about 2.85% of the water by weight.

This page helps with arithmetic and is not a substitute for a tested recipe; if in doubt, throw the batch out. Sources: Virginia Cooperative Extension, FST-328P “Vegetable Fermentation” (J. Eifert, R. Boyer, R. Williams, 2025); National Center for Home Food Preservation, University of Georgia, recipes “Sauerkraut” and “Dill Pickles” (adapted from the USDA Complete Guide to Home Canning, 2015); Clemson Cooperative Extension HGIC, “Making Sauerkraut” and “Canning Foods: the pH Factor” (HGIC 3030); salt weights from manufacturer labels. For meat and poultry brines see the brine calculator; related: canning altitude calculator, food shelf life calculator and cups to grams converter. How we check our calculators.