Salt Reference

Salt is the master variable in fermentation, and not all salts are the same. They differ in purity (how much is actually sodium chloride), in crystal size (how much weight fits in a spoon), and in additives (iodine, anti-caking agents) that can inhibit your bacteria or cloud your brine. Because salt % is always by weight, the safe habit is to weigh in grams and ignore spoons. The table below gives every value the Salt Converter uses, so a recipe written for one salt converts cleanly to another.

Salt types

Grams per tablespoon are approximate and vary with how packed the crystal is — they are here for intuition and spoon-to-spoon conversion, not as a substitute for a scale.

Salt	% NaCl	g / Tbsp	Iodized	Anti-caking	Notes
Pickling / canning salt	100	~18	No	No	Purest; fine grain, dissolves clear with no clouding. Ideal.
Fine sea salt	99	~18	No	No	Excellent default — pure and fast-dissolving.
Diamond Crystal kosher	100	~9.7	No	No	Flaky and light — about half the weight per Tbsp of table salt. Weigh it.
Morton kosher	100	~15	No	Yes (YPS)	Denser flake than Diamond Crystal; trace anti-caking agent, fine for ferments.
Coarse sea salt	98	~16	No	No	Trace minerals; weigh by mass — coarse crystals pack unpredictably.
Himalayan pink	98	~17	No	No	Trace minerals give the color; behaves like coarse sea salt. Weigh.
Grey sea salt (sel gris)	92	~16	No	No	Moist (~8% water), so use more by weight to hit the same NaCl.
Table salt (iodized)	97	~19	Yes	Yes	AVOID — see below.

Note

The percentages above are NaCl purity, not strength. When you tell a calculator you are using grey sea salt (92% NaCl), it scales the grams up so the delivered NaCl still lands on your target band. A 2.5% target with grey salt needs more grams on the scale than the same target with pickling salt.

What NOT to use: iodized table salt

Caution

Do not ferment with iodized table salt. Two of its additives work against you:

• Iodine is antimicrobial — it suppresses the very lactic-acid bacteria you are trying to grow, so ferments stall, sour weakly, or fail.
• Anti-caking agents (often containing yellow prussiate of soda or aluminosilicates) cloud the brine and can leave a chalky sediment.

If iodized table salt is all you have, it will not make a ferment unsafe on its own, but it routinely makes ferments fail to acidify — and a ferment that fails to reach a safe pH is a safety problem. Use pickling, fine sea, or kosher salt instead.

Tip

When a recipe just says “salt,” assume non-iodized, additive-free salt and weigh in grams. A tablespoon of Diamond Crystal kosher (~9.7 g) delivers barely half the salt of a tablespoon of table salt (~19 g) — swapping spoon-for-spoon can under- or over-salt a jar by a wide margin. Convert by weight with the Salt Converter.

Quick guidance

• Best choices: pickling/canning salt, fine sea salt, plain (non-iodized) kosher salt. Pure, additive-free, clean-tasting.
• Fine for ferments: coarse sea salt and Himalayan pink — just weigh them; their coarse crystals mislead the eye. Grey sea salt works but is moist, so use more by weight.
• Avoid: iodized table salt (iodine inhibits, additives cloud). Avoid any salt listing dextrose or “free-flowing” additives if you want a clear brine.

See also

• Salt Converter — match any two salts by the NaCl they deliver
• Salt Percentage — total-weight vs equilibrium-brine %, with worked math
• Salt & Osmosis — why the percentage, not the spoon count, is what matters
• Brine & Salinity calculator — grams for any batch, purity-corrected