Celtic Sea Salt: The Brand, the Gray Salt Behind It, and How to Use It

Celtic Sea Salt is a brand name first and a type of salt second. The company says Dr. Jacques Delangre founded it in 1976 and coined the word “Celtic” to honor a harvesting method it traces back to the Celts, though we found no historical source showing the Celts harvested sea salt this way. Its Light Grey Celtic is a moist gray sea salt of the kind French producers call sel gris, gray salt. You may also read that gray salt is fleur de sel that sank to the bottom of the pan, but Guérande’s official specification says the two form in different places in the same pan and are harvested separately.

At a glance

The brand and the name

Celtic Sea Salt says Dr. Jacques Delangre founded it in 1976, and that the name refers to a hand-harvesting method it traces back to the Celts and Mayans.² Its FAQ says Delangre coined “Celtic” to honor where those methods came from.¹ That’s the company’s story. We found no historical source showing the Celts harvested sea salt this way, so think of the Celtic link as branding.

As for where it’s harvested, the brand’s FAQ says its salt is hand-harvested from ocean waters, and that Light Grey Celtic gets its gray color from coastal salt beds, some more than 1,000 years old. The two places it names, Villena and Catalonia in Spain, are for its river salt and its pink cave salt.¹ We didn’t find anything on those pages saying where Light Grey Celtic itself comes from. If origin matters to you, check the package.

How gray salt is made: the Guérande example

One well-documented gray salt comes from Guérande, on France’s Atlantic coast, where the salt has had a European geographical indication since 2012.⁵ The protected area spans two French départements, Loire-Atlantique and Morbihan. Its official specification lays out the process in detail:³

• Where it forms. Gray salt forms as crystals on the clay bottom of the final pans, called œillets. Fleur de sel forms as crystals floating in sheets on the surface of the same pans and gets skimmed off separately.
• Who harvests it and how. The harvester, the paludier, gathers gray salt by hand from the brine with a las, a tool with a handle about 5 meters long.
• When. Harvest runs roughly mid-June to mid-September, every day the weather allows.
• Draining. The salt drains for several hours on a raised platform at the edge of the pan, then gets wheeled to a storage area on the embankments.
• What’s allowed. The salt isn’t washed, and additives are prohibited. Gray salt can contain up to 12% moisture and up to 1% insoluble matter.

The color comes from those insolubles, which the specification describes as fine particles of clay. The earliest written record of salt pans around Guérande dates from 15 December 854, in the Cartulary of Redon.³

You’ll often read that gray salt is fleur de sel that sank to the bottom of the pan. The Guérande specification says the two form in different places in the pan and are harvested separately. It doesn’t describe one turning into the other.³ For the surface salt, see fleur de sel.

Flavor and texture

The Guérande rules allow gray salt up to 12% moisture.³ In the kitchen it feels damp, tends to clump and has a firm crunch. The brand credits its salt’s moisture to brine (“mother liquor”) left in the salt, and says moisture varies with climate and mineral content.¹

On taste, America’s Test Kitchen found that sea salts vary in color but only slightly in flavor, and that they taste no different from table salt once mixed into food.⁶ If gray salt tastes brinier or more mineral at all, you’ll notice it most when the crystals are eaten whole on top of food. We found no measurement of that, though.

How to use it

As a finishing salt. America’s Test Kitchen recommends sea salts as finishing salts, scattered on food just before serving.⁶ Coarse gray salt is great on steak, roast vegetables, tomatoes and salads, where the crystals stay whole.

In cooking. In pasta water, soups, stews and brines, the crystals dissolve, and salt at its most basic is sodium chloride, whatever the source. The crystals are big and damp, so a spoonful holds a different amount of salt than a spoonful of table salt. We found no published weight per teaspoon for gray salt, so season to taste or weigh it.

Grinding. The brand says you can dry its salt gently over low heat if it’s too damp to grind, and advises against metal containers and grinders.¹ That’s the company’s advice.

Buying and quality

Here’s what the label can tell you: the producer, the origin, whether it’s protected (Sel de Guérande, for example), and whether anything besides salt is listed. Guérande salt can’t contain additives.³ For other gray salts, check the ingredient list.

Storage

The brand calls salt nature’s original preservative, says expiration dates are printed because some retailers ask for them, and suggests plastic, glass, ceramic or wood containers.¹ We found no shelf-life study for gray salt. Keep it covered.

Minerals, sodium and iodine

Minerals. The brand says its salt contains more than 70 trace minerals and elements.² The American Heart Association says sea salt may contain trace levels of minerals like magnesium, potassium and calcium, and that for heart health, total sodium intake is what matters most.⁴ We found no independent analysis of Celtic Sea Salt’s mineral content, so we can’t back up claims that it’s a meaningful source of iron or calcium.

Sodium. Table salt, kosher salt and most sea salts are about 40% sodium. A sea salt can show less sodium per teaspoon just because fewer big crystals fit in the spoon.⁴ None of the sources we found treat moist gray salt as a low-sodium salt. The FDA’s Daily Value for sodium is less than 2,300 mg a day,⁷ and the World Health Organization recommends adults stay below 2,000 mg a day, with raised blood pressure as the main health effect of eating too much.⁸

Iodine. The brand says it adds no iodine and that a natural trace of about 0.2 ppm is present.¹ The NIH Office of Dietary Supplements notes that specialty salts like sea salt usually aren’t iodized.⁹ If you rely on salt for iodine, keep iodized salt around too. See iodized vs. non-iodized salt.

Lead. The brand reports a typical lead content of about 0.68 micrograms per serving and says it tests each lot for heavy metals.¹ That’s the company’s own number. We found no independent test.

Substitutes and comparisons

• Celtic salt substitutes
• Celtic sea salt vs. table salt
• Celtic salt vs. Himalayan salt
• Fleur de sel, sea salt, kosher salt and table salt
• Cooking with sea salt and the best salt for cooking
• Too much sea salt