What is Fleur De Sel?

Posted on 30 Jul 2015 21:28

Fleur de sel is French for "flower of salt." It is a very expensive kind of sea salt that gathered from evaporated sea water from several coastal areas of the world, including most famously from the marshes of the Guérande in Brittany (Fleur de sel de Guérande) as well as other areas of the west coast of France such as Vendée, Aigues-Mortes, Île de Ré, and Noirmoutier1, and Aigues-Mortes in the South.

The slightly coarse crystals are fine, irregular, and a silvery off-white, grey to pink color. There are no desiccants or drying-agents used, so it has a higher moisture content than most salts. It must be sprinkled by hand or by spoon as the high moisture makes it impossible to use a salt shaker.

Due to its costs, and according to some, its delicate, less salty flavor, fleur de sel is normally used as a condiment or "finishing salt" to be sprinkled on food rather than as a cooking seasoning.

However, as expensive salts from around the world become more fashionable and trendy, you may come across recipes telling you to use fleur de sel to season a pot of chili. Since it can cost from $1.50 to $3.00 an ounce in the United States, you may think twice before following such instructions (beware of fakes).

Fleur de Sel - French sea salt from Guérande

Close-up view of Fleur de Sel salt crystals, from Guérande in Brittany
Image by Christian Mertes via wikimedia

Fleur de Sel - French sea salt from Guérande

Close-up view of Fleur de Sel salt crystals, from Guérande in Brittany
Image by Christian Mertes via wikimedia

Production of Fleur De Sel

Fleur de sel is hand-harvested from salt marshes by "paludiers" in a labor-intensive process. Dykes are used to funnel and trap seawater into lagoons or "salt pans," where it slowly evaporates. It is said that if the climate and the wind is just right, a salt layer begins to form on the surface in delicate flower-like or snowflake-like patterns. Whether the wind component (only from the East?) is true or simply a marketing legend intended to justify a higher cost is unclear, but regardless, this layer of salt that forms at the top of the evaporating salt-bed has less minerals and the crystals are much smaller than what will result once the salt sinks to the bottom and the water continues to evaporate.

Traditionally, this surface layer is very carefully raked off by hand and allowed to dry a bit more before being sold as fleur de sel, without any further refining. The crystals are flat and layered, somewhat like mica, causing them to break up and peel away from each other. Although hand raking still occurs, today, mechanical means are sometimes used.

After the fleur de sel is harvested from the surface, the rest of the salt sinks to the bottom and forms larger crystals that form a cheaper gray salt that mixes with the clay that lines the bottom of the salt pan. This salt is also harvested and marketed as sel gris. Although this is also sold as-is and is itself expensive, it is basically dirty salt, so impure it would usually be considered undesirable.

Below is a video showing the harvesting of fleur de sel from the "Marais Salants," the salt marshes of Vendée, the smallest of 3 salt marshes of the area. In it, you will be able to see the snow-flake-like formations of salt crystals on the surface of the water, which is gathered with a special rake.

Similar salts are also produced from the coastal regions of other countries, including flor de sal from Portugal, Maldon salt from the U.K. and Trapani salt from Sicily.

Flavor of Fleur de Sel

The flavor of fleur de sel is usually described as more delicate and less salty than regular table salt, with less bitterness. Mineral "after-notes" are often perceived. Not everyone, however, has the same experience. It is often claimed that each crystal of fleur de sel forms around a single alga, which some people say gives the salt the smell of violets. It is highly doubtful that this is true, and even more doubtful that a human nose could pick up an smell from a single microscopic alga organism.

Chemistry Professor Robert L. Wolke, author of What Einstein Told His Cook, who is a syndicated columnist for the Washington Post, wrote a series of articles that challenged the claim that fleur de sel and other expensive sea salts taste different because of their chemistry and he repeated this challenge in his book. Wolke correctly states that all salt, whether mined from the Earth, or gathered from evaporated sea water, is sodium chloride (NaCl). Although there are trace minerals present fleur de sel, such as sulfate, magnesium, calcium, and trace amounts of many other minerals. According to Wolke, the idea that one salt can be "saltier" than another is silly, as all salt is essentially just salt, and the presence of trace minerals are too slight to be perceived. If different salt tastes different, it is because of the different crystal sizes and shapes. Therefore, once any kind of salt is dissolved in water, the differences evaporate. Wolke provides no actual evidence to support these claims, however, other than his explanation.

Jeffrey Steingarten chellenged Wolke's claims in his book It Must've Been Something I Ate: The Return of the Man Who Ate Everything. With the help of scientists, he conducted taste comparison experiments using various sea salts, including fleur de sel salts, dissovled in water, compared to American table salt. The results of the tests were not statistially significant, although a slight majority could detect a difference in some salts. Note that this does not necessarily mean they preferred the taste.

It is hard to draw any conclusions from these tests, which, to my knowledge, were not published in any scientific journals. In truth, you may or may not perceive a difference in the taste of fleur de sel sprinkled on food, or dissolved in a solution (soups, sauces, etc.). Fleur de sel is at least 99% sodium chloride, and once dissolved in a large amount of water, the minerals may be too diluted to be detectable, although some may still detect a difference.

Fleur de sel, due to it's fluffy delicate crystals, dissolves quite easily when sprinkled onto moist foods, and Wolke's contention that we could not taste the minerals because they are too trace is probably incorrect. Steingarten contacted Harold McGee, food scientist and author of On Food and Cooking: The Science and Lore of the Kitchen, who stated as much, saying that the the minerals in fleur de sel and other such salts, even at low concentrations, would probably affect the taste and texture of food.

The sulfates in fleur de sel should be generally detectable, probably through the aroma and the other minerals may react with the food in different ways, changing the flavor, even if we don't "detect" taste of the minerals themselves.

It is unlkikely that you will notice any real improvement in your dishes using fleur de sel instead of table salt as a seasoning agent during the cooking process, especially if the salt is dissolved in a large solution at low concentrations. However, you may well enjoy a marked difference using it as a condiment to season foods at the table. It is, as most things, up to you whether you like it. Hopefully, given the knowledge that there may well be no difference, at least to many people, your expectations will not cause you to taste a difference that is not there. The truth is, however, unless the difference is very pronounced, we can't always be sure! Expectations DO influence are flavor perceptions.

Ironically, the impurities that are supposed to make such a huge difference are present in large quantities in sel gris which basically is salt with clay in it, so that it stretches the definition of "salt" if left alone. While you may pay top prices for sodium chloride with just a touch of other minerals in it, you would probably hesitate to pay the same for what is essentially dirt impregnated salt. Yet, many of the highly prized and highly colored sea salts taste much different than fleur de sel or any table salt because they are mixed with clays or even volcanic ash. It is ironic that such debate rages about the differences in salts with just slight variations of trace mineral content, when such highly impure salts are sold at the same kinds of prices.

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