Iodized vs. Non-Iodized Salt: How Do They Compare?

Does it matter which salt you grab? In the pot, no. America’s Test Kitchen’s tasters couldn’t tell iodized from non-iodized salt,¹ and home-canning guidance says you can safely make pickles with either.² The real difference is nutrition: US iodized salt carries 45 micrograms of iodine per gram, added by salt makers since the 1920s and still voluntary, while sea salt, kosher salt, Himalayan salt and fleur de sel usually aren’t iodized.³ So if you’ve switched to a specialty salt at home, you’ve most likely switched to a non-iodized one.

Side by side

	Iodized salt	Non-iodized salt
What it is	Salt with added iodide; US labels must say “This salt supplies iodide, a necessary nutrient”⁴	Plain salt, which US rules require to be labeled as not supplying iodide, plus most specialty salts⁴³
Iodine	45 mcg per gram on US labels; measured samples average 47.5 to 50.7³	Noniodized sea salt provides virtually no iodine³
Typical additives	Morton iodized: calcium silicate (anticaking agent), dextrose, potassium iodide⁵	Varies by product: Morton kosher salt lists an anticaking agent, yellow prussiate of soda;⁶ ATK reports Diamond Crystal kosher salt has none⁷
Forms	Table salt	Plain table salt and specialty salts such as sea, kosher and Himalayan salt
Sodium	About 40%, like other salts⁸	About 40% for table, kosher and most sea salts⁸
Taste	No detectable difference from noniodized salt in ATK’s test¹	Same
Pickling	Safe; may darken pickles²⁹	Canning or pickling salt is the recommended choice²
Price	No dated, sourced comparison found	No dated, sourced comparison found

How much iodine is in each

Salt (scope)	Iodine	Source
US iodized salt, label	45 mcg per gram (45,000 µg/kg)	NIH ODS³
US iodized salt, measured samples	47.5 to 50.7 mcg per gram on average	NIH ODS³
Morton iodized table salt, label	68 mcg per ¼ teaspoon (1.5 g)	Morton⁵
Swiss iodized table salt	25 mg/kg, the national fortification level since 2014	Swiss FSVO 2016¹⁰
Sea salts, 7 samples bought in Switzerland	Below 20 µg/kg or not detected in four; 28 to 54 µg/kg in three	Swiss FSVO 2016¹⁰
Fleur de sel, 4 samples	21 to 61.7 µg/kg	Swiss FSVO 2016¹⁰
Himalaya salt, 4 samples	Below 20 µg/kg in all four	Swiss FSVO 2016¹⁰

The rows come from different labels and studies, so compare the orders of magnitude, not the decimals. The highest specialty-salt figure in the Swiss survey, 61.7 µg/kg, is more than 700 times lower than the US iodized label, by our math. The Swiss report says plainly that specialty salts generally aren’t iodized.¹⁰

A ¼ teaspoon of Morton’s iodized salt gives you 68 mcg,⁵ close to half the adult recommended intake of 150 mcg a day, by our math.³

Why the iodine matters

Your thyroid hormones, thyroxine (T4) and triiodothyronine (T3), are built with iodine. Too little causes iodine deficiency disorders. Goiter is usually the first sign, and in pregnancy severe deficiency can cause major neurodevelopmental deficits. The adult recommended intake is 150 mcg a day, rising to 220 mcg in pregnancy and 290 mcg while breastfeeding. The adult upper limit is 1,100 mcg.³

Salt iodization programs have cut iodine deficiency dramatically worldwide, and about 88% of households now use iodized salt.³ The Codex standard for food-grade salt says salt shall be iodized in iodine-deficient areas.¹¹

Who should think about it. The ODS says the general US population gets enough iodine, but surveys suggest many pregnant women may not. Two things make salt a weaker iodine source in American kitchens. Most of the salt we eat comes from processed foods, and manufacturers almost always use noniodized salt. And if you switch to kosher, sea or Himalayan salt at home, you’re usually switching to a noniodized salt. Seafood, eggs, milk and milk products are among the best food sources of iodine.³ We’re not claiming iodized salt treats or prevents any condition; this is about a public-health fortification program.

Taste

You’ll often hear that iodine gives salt a bitter or metallic aftertaste some people can pick up. America’s Test Kitchen’s tasters found no detectable difference in taste between iodized and noniodized salt.¹ We found no study of individual sensitivity to iodine in salt, so that part of the claim is untested, not disproven.

Pickling and canning

A common warning says iodine kills the bacteria fermentation needs, so iodized salt must never go into pickles. The National Center for Home Food Preservation says otherwise: you can safely make pickles with either iodized or noniodized table salt.² It does recommend canning or pickling salt, for two reasons it lists among causes of pickle problems: iodized salt can darken pickles, and anticaking agents or other additives can cause cloudy brine or white sediment.⁹¹² For fermented pickles and sauerkraut, how much salt matters more than which kind. NCHFP warns not to cut back, because salt is vital to safety and texture.¹² Flake salt isn’t recommended for pickling because its density varies.

Can one stand in for the other?

Yes, for flavor, in any recipe. Swapping changes only the iodine and, if you measure by volume, sometimes the amount of salt, since non-iodized salts come in every crystal size.

Per 1 teaspoon iodized table salt	Starting amount	Treatment
Any salt, by weight	The same weight	Computed
Noniodized table salt, canning and pickling salt, or fine sea salt (Morton)	1 teaspoon	Attributed (Morton products only)
Morton kosher salt	1¼ to 1½ teaspoons; start at 1¼	Disputed
Diamond Crystal kosher salt	2 to about 2⅛ teaspoons; start at 2	Disputed
Flaky sea salt	Weigh it; by volume no published figure exists	Method

How these were worked out. By weight: the Codex standard requires food-grade salt to be at least 97% sodium chloride on a dry basis.¹¹ By volume: Morton’s chart treats its table salt, fine sea salt and canning and pickling salt as equal, teaspoon for teaspoon, within its own products.¹³ For kosher salt, named sources disagree. America’s Test Kitchen’s rule of thumb gives 1½ teaspoons of Morton kosher or 2 of Diamond Crystal per teaspoon of table salt;¹¹⁴ Morton’s chart gives 1¼ teaspoons of its kosher salt;¹³ and ATK’s own weights (about 6 g per teaspoon of table salt, 4.8 g for Morton, 2.8 g for Diamond Crystal) work out to 1¼ and about 2⅛.⁷ We start at the lower figure, because salt is easy to add and hard to take out. The full disagreement table is on the kosher salt page.

Storage

For iodized salt, the Codex standard includes storage precautions meant to limit iodine loss.¹¹ We found no shelf-life figure from a regulator for either kind. Keep both dry and closed.

What isn’t known

Whether some people can taste iodine in salt. We found no study.
How much iodine US iodized salt loses in a home pantry over time.
A dated, sourced price comparison.
A published grams-per-teaspoon figure for flaky sea salts.

Salt Types and Measurements, America’s Test Kitchen. americastestkitchen.com · Publication ↩ ↩² ↩³ ↩⁴
Salts Used in Pickling, National Center for Home Food Preservation. nchfp.uga.edu · Reference work ↩ ↩² ↩³ ↩⁴
Iodine: Fact Sheet for Health Professionals, NIH Office of Dietary Supplements. ods.od.nih.gov · Regulator ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰
21 CFR 100.155, Salt and iodized salt, Electronic Code of Federal Regulations. ecfr.gov · Regulator ↩ ↩²
Morton Iodized Table Salt, product page, Morton Salt. mortonsalt.com · Merchant ↩ ↩² ↩³
Morton Kosher Salt Flakes, product page, Morton Salt. mortonsalt.com · Merchant ↩
Kate Shannon Levine, The Best Kosher Salt, America’s Test Kitchen, 2019. americastestkitchen.com · Publication ↩ ↩²
Sodium Sources: Where Does All That Sodium Come From?, American Heart Association, 2025. heart.org · Reference work ↩ ↩²
Causes and Possible Solutions for Problems with Pickled Foods, National Center for Home Food Preservation. nchfp.uga.edu · Reference work ↩ ↩²
Esther Infanger and Max Haldimann, Report on the composition of prevalent salt varieties, Swiss Federal Food Safety and Veterinary Office, 2016. warwick.ac.uk · Regulator ↩ ↩² ↩³ ↩⁴ ↩⁵
Standard for Food Grade Salt, CXS 150-1985 (rev. 2012), Codex Alimentarius. services.bis.gov.in · Standard ↩ ↩² ↩³
General Information on Pickling, National Center for Home Food Preservation. nchfp.uga.edu · Reference work ↩ ↩²
Salt Conversion Chart, Morton Salt. mortonsalt.com · Merchant ↩ ↩²
Eden Faithfull, The Wrong Brand of Kosher Salt Could Ruin Your Dinner, America’s Test Kitchen, 2022. americastestkitchen.com · Publication ↩

Iodized vs. Non-Iodized Salt: Iodine, Taste, Pickling and Swaps