Fleur de Sel Substitutes, by Whether the Salt Sits on Top or Dissolves In

Fleur de sel, “flower of salt,” is the thin layer of crystals that forms on the surface of the brine in seawater salt pans and is skimmed off by hand.¹ Its job is almost always the same: a pinch scattered over food just before it is eaten, where the crystals stay whole and crunch. America’s Test Kitchen recommends sea salts for exactly this use, as finishing salts.² So the best substitute is whatever gives you a clean, crisp crystal on the surface. If fleur de sel has been measured into a dough or a sauce where it dissolves, the question is only how much salt, and almost any salt will do.

Quick answer

How the ratios on this page are labeled

• Computed: based on a measurable physical relationship, with the source named.
• Attributed: a named source publishes this ratio. We quote it as theirs.
• Disputed: named sources give different answers to the same swap. We show each one and do not average them.
• Method: we found no published ratio. We give a direction and a cautious starting point, and say so.

We found no published weight for a teaspoon of fleur de sel, and no measured comparison of how salty it tastes against any other salt. That is why most amounts on this page are Method starting points.

What makes fleur de sel different

The best-documented fleur de sel comes from Guérande, on France’s Atlantic coast, where it is a protected name with a published specification. Two salts come out of the same pans. Gray salt (sel gris) crystallizes on the clay bottom and takes its color from fine clay particles; fleur de sel forms as crystals floating in sheets on the surface and is skimmed off by hand.¹ The specification limits fleur de sel to under 0.20% insoluble matter, against up to 1% for gray salt, and allows up to 12% moisture.¹ The salt is not washed, and no additives are allowed.¹ It is white, sometimes faintly pink.¹

What that means at the table is texture: fine, slightly damp crystals that hold their shape for a moment before dissolving. That description is ours. Flavor is a smaller matter. ATK found that sea salts vary in color but only slightly in flavor, and that sea salt tastes no different from table salt once mixed into food.²

If fleur de sel is finishing a dish

1. Maldon or another flaky sea salt

Maldon gives the same kind of crunch in a different shape. It is made in Maldon, a town in Essex in southeastern England.³ Its maker collects seawater according to the lunar cycle and brings it to “a galloping boil,” and the thin pyramid-shaped flakes form at the water’s surface, shaped by surface tension.⁴ Like fleur de sel, then, the crystals form at the top of the brine, though by boiling rather than by sun and wind.¹ The flakes are larger and crisper than fleur de sel’s fine crystals; that comparison is our observation.

Ratio (Method): Use it by the pinch, as you would fleur de sel, and taste. No published gram-per-teaspoon figure exists for either salt that we found, so there is no basis for a measured swap. Crush the flakes between your fingers if you want smaller crystals.

2. Diamond Crystal kosher salt

If the pantry holds only kosher salt, Diamond Crystal is the better of the two big US brands for finishing. ATK describes it as made by the Alberger process, in which brine is heated and stirred in open pans so that hollow, pyramid-shaped crystals form at the surface.⁵ ATK’s tasters preferred its “delicate and fleeting crunch.”⁵ Morton’s kosher salt is instead pressed through rollers into thin, hard flakes.⁵

Kosher salt takes its name from its traditional use in koshering meat, not from any difference in the salt itself.²⁶

Ratio (Method): By the pinch, to taste. If you are using Morton, use a lighter hand: a teaspoon of Morton kosher salt weighs 4.8 grams against 2.8 grams for Diamond Crystal, ATK found,⁵ so a pinch of Morton carries more salt.

3. Sel gris (gray salt)

Gray salt is the other salt from the same pans, so it is the natural relative.¹ It is gray from clay and damp; the brand Celtic Sea Salt says the natural brine stays in its gray salt.⁷ That suits heartier food, such as roast meat or root vegetables, better than delicate fish or sweets. That is a kitchen judgment.

Ratio (Method): By the pinch, to taste. Gray salt crystals are usually chunkier than fleur de sel’s (our observation), so use fewer of them, or crush them first.

4. Coarse Himalayan pink salt, for color

Himalayan pink salt is rock salt, not sea salt. Commercial supplies come from Pakistan, where the state-owned Pakistan Mineral Development Corporation runs the Khewra mine,⁸⁹ and the beds were laid down by ancient oceans about 250 million years ago, according to Harriet Hall.¹⁰ Its pink color comes from traces of iron oxide.⁸ A coarse grind gives crunch and a pink fleck on a salad or steak, but its crystals are hard and chunky rather than fine and damp.

Ratio (Method): By the pinch, to taste.

If fleur de sel is measured into a recipe

Some recipes, often for caramels, shortbread or salted butter, measure fleur de sel into the mixture, where it dissolves. Here the crystal no longer matters. ATK notes that salt in its most basic form is sodium chloride whatever its source.² What matters is the amount of salt.

By weight (Computed, upper limit): The Codex standard for food-grade salt requires at least 97% sodium chloride on a dry basis,¹¹ and Guérande fleur de sel can hold up to 12% moisture.¹ A gram of fleur de sel therefore cannot carry more salt than a gram of dry salt. If the recipe gives grams, use no more than the same weight of any food-grade salt, and taste.

By volume (Method): This is where substitutes go wrong, because a spoon holds very different weights of different salts. Large crystals carry less salt per teaspoon simply because fewer of them fit,¹² and ATK weighs a teaspoon of table salt at about 6 grams, Morton kosher at 4.8 and Diamond Crystal at 2.8.⁵ With no published weight for fleur de sel, start with about half the volume if you are using table salt and about three quarters with Morton kosher salt, then taste. Diamond Crystal is the lightest of the three, so it is the safest to start at equal volume. These are cautious starting points, not measured equivalents.

Other options

• Ordinary coarse sea salt. Coarse crystals give crunch, but in our judgment they are harder and slower to break down on the tongue than fleur de sel’s. Use by the pinch (Method).
• Table salt. Fine and dense, it disappears into food instead of sitting on top. Fine for a dissolved use, at the volume above; a poor finishing salt.

Notes for every swap

• Iodine. Fleur de sel is not a source of iodine. The NIH Office of Dietary Supplements lists fleur de sel, sea salt, kosher salt and Himalayan salt among specialty salts that are not usually iodized.¹³
• Sodium. Table salt, kosher salt and most sea salts are all about 40% sodium,¹² so swapping one for another does not change sodium intake unless you use less.

What isn’t known

• No published weight per teaspoon was found for fleur de sel, so volume swaps on this page are starting points.
• No sensory test comparing fleur de sel with Maldon, sel gris or kosher salt as a finishing salt was found.
• Fleur de sel from other regions follows its producers’ own rules; the figures on this page describe Guérande’s specification.

Related

• Fleur de sel, fleur de sel vs. Maldon salt and fleur de sel vs. kosher salt
• Fleur de sel vs. sea salt and fleur de sel vs. Himalayan salt
• Maldon sea salt, Celtic sea salt, kosher salt, Himalayan salt and sea salt
• Maldon salt substitutes, Celtic salt substitutes and sea salt substitutes
• Cooking with sea salt and too much sea salt