Salt Percentage

“2% salt” is meaningless until you say 2% of what. Three different denominators are in common use, and they give different grams for the same jar. This page defines all three, shows the math, and tells you which to use. Throughout, salt % is always by weight — weigh everything in grams.

The three bases

Info

A percentage is just salt_g / base_g × 100. The only question is what goes in the denominator. Pick the base that matches how the salt is delivered: rubbed onto the vegetable (dry salt) or dissolved in a brine the vegetable is submerged in (equilibrium brine).

1. Total-weight % (dry-salt method)

Salt as a percentage of the vegetable weight only — no added water. This is the sauerkraut / dry-salt convention, where the vegetable releases its own brine. Default 2.0%.

salt_g = veg_g × target% / 100

Worked: 1000 g shredded cabbage at 2.0% dry → 1000 × 2.0 / 100 = 20 g salt.

2. Equilibrium-brine % (submerged method)

Salt as a percentage of the combined vegetable + water weight. Because salt migrates until tissue and brine reach one concentration, this makes the whole jar settle at your target — which is what governs flavor and safety. Default 2.5%, range 2.0-3.0%.

salt_g = (veg_g + water_g) × target% / 100

Worked: 800 g vegetable + 1000 g water at 2.5% EQ → 1800 × 0.025 = 45 g salt. That salt is exactly 2.5% of the combined vegetable + water weight, so the whole jar equilibrates to 2.5%.

3. Brine strength % (legacy, water-only)

Salt as a percentage of the water only, ignoring the vegetable. This is the old-cookbook convention (“a 5% brine”). It overshoots, because once the vegetable’s water joins the brine the true concentration drops. We treat it as legacy — record it, but don’t target it.

salt_g = water_g × target% / 100

Worked: 1000 g water at 2.5% brine strength → 25 g salt — but with 800 g of vegetable also giving up water, the jar equilibrates well below 2.5%.

Side by side

Same jar (800 g vegetable, 1000 g water), same “2.5%”, three answers:

Method	Denominator	Salt for 2.5%	Where the jar lands
Total-weight % (dry)	veg only (no water added)	20 g per 1000 g veg	on target
Equilibrium-brine %	veg + water	45 g	on target (finished)
Brine strength % (legacy)	water only	25 g	below target after equilibration

Caution

Don’t mix bases mid-recipe. A “5% brine” (water-only) and a 5% equilibrium ferment are not the same jar, and the legacy figure can land a submerged ferment under the 2.0% safety floor once the vegetable’s water dilutes it. When unsure, use equilibrium %. See Safety First.

Note

Salt purity matters too. Fine sea, pickling, and kosher salts are ~97-100% NaCl; grey/unrefined sea salts can be ~92%. The calculators correct grams for the purity you select so the delivered NaCl hits your target.

See also

• Salt & Osmosis — why the percentage is the master variable
• Brine Chemistry — how the equilibrium in method 2 actually forms
• Brine & Salinity calculator — equilibrium-brine grams for any batch
• Dry-Salt calculator — total-weight grams for kraut and dry-salted ferments