Kosher Salt: What It Is, Morton vs. Diamond Crystal, and How to Measure It

A teaspoon of Morton kosher salt weighs 4.8 grams. A teaspoon of Diamond Crystal weighs 2.8 grams.¹ In American kitchens, kosher salt mostly means one of those two brands, and that gap is the single most useful thing to know about it. Otherwise it’s coarse-grained salt, plain sodium chloride like any other, named for its traditional use in koshering meat. Weight for weight, it tastes like any other salt, too.

At a glance

What kosher salt is

The name comes from what the salt was used for, not how it was made. Kosher salt was originally used for koshering meat. Its coarse grains draw blood out of meat, as Jewish dietary law requires, and that’s where the name comes from.⁷³ Morton says its kosher salt is kosher certified.⁵ You’ll sometimes read that any salt made under rabbinical supervision can be called kosher salt. We couldn’t find a source for that, so we’re leaving it out.

The two big brands get their large grains in different ways. ATK’s 2019 review says Diamond Crystal is made by the Alberger process: brine is heated and stirred in open containers, and hollow, pyramid-shaped crystals form on the surface and never get flattened. Morton’s salt is evaporated from brine in vacuum evaporators, then pressed through rollers into large, thin flakes and screened for size.¹ Morton now sells it as “Kosher Salt Flakes.”⁵

Neither is iodized. Kosher salt usually has no other additives either, with Morton the exception because of its anticaking agent.³ Morton’s label lists salt and yellow prussiate of soda (an anticaking agent). ATK reports that Diamond Crystal has no anticaking agents.⁵¹

Flavor

Weight for weight, kosher salt tastes like any other salt. In ATK’s test, chicken broths seasoned with equal weights of Morton and Diamond Crystal tasted exactly the same. Where tasters did notice a difference was texture. Sprinkled plain and on buttered bread, they preferred Diamond Crystal’s “delicate and fleeting crunch,” and found Morton’s grains harder and tougher to spread evenly.¹

You’ll hear that kosher salt tastes “cleaner” or “milder” than table salt, mostly on the idea that iodine or additives give table salt an off taste. ATK’s tasters couldn’t tell iodized from noniodized salt.⁷ So the case for kosher salt is how it handles, not how it tastes.

How kosher salt is used

ATK’s testers make kosher salt their first choice for seasoning meat, because the large grains spread easily and cling.⁷ The coarse grains are also easy to pinch and easy to see on food, so you can judge how much has gone on. That’s a cook’s rule of thumb, not a tested finding. Morton suggests its kosher salt for brining poultry and for grilled meats and vegetables.⁵

The bigger grains dissolve more slowly than table salt, which Tufts says can help season the surface of food with less salt.³ That’s why many bakers keep fine salt for quick doughs and batters, or dissolve kosher salt in the recipe’s liquid first.

Two older claims don’t hold up as stated. Kosher salt isn’t a curing salt. Curing salt is a separate product, covered at curing salt. And we couldn’t find a source showing kosher salt beats other salts for pickling brines. Morton’s kosher salt contains an anticaking agent, and dedicated pickling salt is sold for that job. For more, see cooking with kosher salt.

Measuring and converting

This is where kosher salt causes real trouble. Reputable sources publish volume conversions that don’t agree, and the brand on the box changes the answer.

Grams per teaspoon

ATK’s 2022 article rounds these to about 5 g for Morton and 3 g for Diamond Crystal.⁸ We couldn’t get Diamond Crystal’s own figure from the company.

Volume swaps: the sources disagree

ATK’s own weights agree with Morton’s chart on Morton (1¼), not with ATK’s rule (1½). The same ATK review also says to cut Morton by 25% when a recipe was written for Diamond Crystal, but its two gram figures work out to a cut of about 40%.¹ We’d rather show you the disagreement than pick a winner. What it means in practice: if a recipe gives salt in grams, weigh it. If it names a brand, use that brand or convert by weight. If it just says “kosher salt,” start low and taste. ATK also recommends weighing salt instead of measuring it by volume.⁸

Buying and storage

Pick one brand and get to know it. Diamond Crystal’s light, hollow crystals are easy to pinch and forgiving if you over-pour. Morton’s denser flakes put more salt in every spoonful.¹⁸ Check the box, too: Morton lists an anticaking agent and Diamond Crystal doesn’t.

We couldn’t find a shelf-life figure for kosher salt from a regulator or standards body. Like any plain salt, it just needs to stay dry.

Safety and health

Kosher salt isn’t lower in sodium by weight. Table salt, kosher salt and most sea salts are about 40% sodium. A teaspoon of kosher salt holds less sodium than a teaspoon of table salt only because fewer of its bigger crystals fit in the spoon.² Tufts puts a teaspoon of kosher salt at 1,920 mg of sodium against 2,325 mg for table salt, without naming a brand. Given the gap between Morton and Diamond Crystal, treat that as a rough figure.³ The FDA’s Daily Value for sodium is less than 2,300 mg a day, about a teaspoon of table salt.¹⁰

Kosher salt gives you essentially no iodine. The NIH Office of Dietary Supplements lists it among the specialty salts that usually aren’t iodized.⁴ If you cook only with kosher salt and count on salt for iodine, keep iodized salt around too. See iodized vs. non-iodized salt.

Substitutes and comparisons

Any salt can stand in for kosher salt by weight. By volume, use the tables above. The full list is at kosher salt substitutes, and here are the comparisons:

• Kosher salt vs. table salt
• Kosher salt vs. sea salt
• Kosher salt vs. Himalayan salt
• Pickling salt vs. kosher salt
• Maldon salt vs. kosher salt
• Fleur de sel vs. kosher salt

If a dish has gone over, see too much salt.