For a pinch of salt

Salt is the common name for sodium chloride (NaCl), a mineral of marine origin present in water when the Earth was still covered by oceans. It was deposited in layers of sediment with each retreat of the sea. An inexhaustible commodity, it is found in abundance in nature, but unevenly distributed and in different forms - as a rock buried in the ground, or as a liquid dissolved in the sea. it's one of the first raw materials that man has extracted and used massively in all aspects of his life," emphasizes Raphaël Haumont, lecturer and researcher at Paris Sud-Paris Saclay University and co-founder of the French Center for Culinary Innovation (CFIC). Salt, which has taken millions of years to produce, is fascinating in this sense, as it is a matter of life and survival. In particular, it regulates water in cells and is a precious source of life. "

The exploitation of salt depends on a variety of techniques corresponding to the different forms the mineral takes. Most often, salt is extracted by subjecting it to natural or artificial evaporation until it crystallizes, a phenomenon that occurs when the density of salt is around 330 grams per liter. Natural brine is thus transformed into salt. Throughout history, societies have combined these operations according to their own technical systems: briquetting in the early Iron Age, Gallic salt furnaces and salt marshes and salt pans dating from the Middle Ages and even Roman times. The direct exploitation of salt deposits, on the other hand, is based on mining extraction techniques. Rock salt (or halite) comes from deposits formed by the evaporation of salty seas or lakes, which can form layers several meters thick. In France, the oldest rock salt deposits were formed between 250 and 200 million years ago. Today, the last active mine is located in Varangéville, Lorraine.

In the 19th century, salt became an essential raw material for the booming chemical industry. It was discovered that soda ash, chlorine, hydrochloric acid and sodium carbonate could be obtained from salt. These chemicals were used in a wide range of industries, from glass and soap to paper, laundry detergents, various cleaners and bleach, whose disinfectant properties were discovered at this time. today, salt is mainly used by industries outside the food consumption sector," explains Annah de Roquefeuil, marketing manager for table salts at the Salins group, one of Europe's leading manufacturers. The chemical industry is undoubtedly the biggest consumer, as salt is a precursor of several elements, such as plastic or elastane. "In 2021, France produced over 5 million tonnes of salt, including 1 million tonnes of sea salt and only 200,000 tonnes for food consumption. the Salins group alone produces an average of 4 million tonnes of salt every year, 30% of which is destined for the chemical industry, followed by snow removal (17%) and food (10%). The trajectory of the company, one of Europe's leading salt producers, is typical of the evolution of the industrial sector that began in the 19th century.

the Compagnie des Salins du Midi was founded in Aigues-Mortes in 1856," explains Annah de Roquefeuil. Faced with the difficulty of selling their salt production, independent salt producers in the south of France joined forces with traders from Montpellier to create a kind of grouping to enable national trade. The common objective was to produce salt and market it for all possible applications. "

Throughout the 20th century, the Compagnie des Salins du Midi expanded its presence throughout France, through acquisitions and mergers, to become the Compagnie des Salins du Midi et des Salines de l'Est (CSME), the main component of the Salins Group. Today, it is the only European player to master and implement all three production techniques - solar, thermal and mining - enabling it to supply salt in all its forms and for all applications. depending on the desired use, we produce different types of salt at our sites," continues the manager. We use our Aigues-Mortes salt marshes for edible sea salt - table salt as we know it - as well as for certain industrial applications. Rock salt from the Varangéville salt mine is used exclusively for snow removal. We also have a refinery in Varangéville and a smaller one in Dax, which enable us to produce the purest salt - with a sodium chloride content of over 99.9% - for a variety of industries, such as the food industry, which needs pure salt for bread and cheese production, and the chemical and pharmaceutical industries. "

Faced with the diversification of industrial uses, which has disrupted and structured the sector, the producer's profession has also had to adapt. tanguy Ménoret, President of the Association française des producteurs de sel marin de l'Atlantique (AFPS), director of the Le Guérandais cooperative and a salt grower, explains: "Salt has been used for thousands of years as a preservative. With its disappearance, we had to find new outlets. "Salt production on the Atlantic coast, which had been dynamic until then, began to decline at the dawn of the 20th century. Cold replaced salt in preservation techniques, and the development of the chemical industry had a profound impact on the sector. The Camargue salt marshes became industrialized, and salt extraction techniques were perfected to the point of becoming almost entirely mechanized around 1950. " The rise of the chemical industry transformed the market, with an ever-increasing demand for chemically pure salt, where impurities were less and less tolerated .s were less and less tolerated," explains Louis Merlin, vice-president of the AFPS, director of the Coopérative de l'île de Ré and a salt worker. Where industrialization and mechanization were possible, as in the Mediterranean and Portugal, changes were made. On the Atlantic coast, the characteristics of the soil made it difficult to install machinery. There was more local resistance to protect the land and defend age-old know-how. "

from the 1970s onwards, a new generation came into the business, keen to preserve know-how and terroirs. In 1979, a training course unprecedented in Europe - the "brevet professionnel de responsable d'exploitation agricole option saliculture" - was launched at La Turballe. Salt production was relaunched with, in particular, the development of fleur de sel, which today accounts for 50% of the income of small-scale producers. The AFPS was created in the 1990s, bringing together the main cooperatives in Guérande, Noirmoutier and the Ile de Ré. tanguy Ménoret confirms: " Our outlet has been to move towards the new artisanal economies by working on product quality. It's a fairly raw product, with no additives. We tried to differentiate ourselves by seeking out quality labels such as Label Rouge or IGP de Guérande, which requires a certain traditional, manual harvesting method. "The AFPS points out that today, 25,000 tonnes of sea salt are produced on the Atlantic coast by small-scale producers using traditional methods, exclusively for human consumption. The challenge of offering a product that focuses on quality rather than volume creates a fragile balance, but one that enables virtuous industries to be maintained. today, people really come to this profession out of a passion for the marsh," confides Louis Merlin. We offer a living product with different characteristics depending on the harvest or the weather. That's the ambivalence of our industry. "Not only is salt an indispensable everyday product, present in every household, but it is estimated that there are almost 14,000 different uses, demonstrating its essential nature.

Three questions for Raphaël Haumont, lecturer and researcher at Paris Sud-Paris Saclay University and co-founder of the French Center for Culinary Innovation (CFIC)

Gault&Millau: What is salt?

Raphaël Haumont: Salt is an ionic NaCl crystal. It's simply made up of sodium and chloride ions. When salt is 99.9% pure, it takes the form of a rock crystal, perfectly transparent and white in the light. When we speak of pink, gray, blue or black salts, we are actually talking about salts with impurities. These impurities depend on a variety of criteria, such as the territory, the way the crystallization took place, the terroir, etc. In Japan, for example, you'll find black salt from sulfur-rich soil with a distinctive eggy odor. An analogy can be made with precious stones, for example. An African diamond is different from an American diamond. The same applies to salt crystals. These impurities, which may account for only one millionth of the salt's composition, are sufficient to color the crystal. Such is the case with iron, which gives the pink color. These impurities can also mix with NaCl, such as zinc or magnesium, to produce a more complete salt, as in the case of Guérande salt. conversely, when we refine salt, we eliminate these impurities, which can be good or bad. The challenge is to retain the small defects without overdoing them.

What are the properties of salt?

R.H. : In the food industry, salt has always been an excellent preservative. It prevents bacteria from proliferating. During fermentation or lacto-fermentation processes, for example, salt allows the interesting ferments to develop as they should. Or when salting fish. Salt is used to get rid of excess water. It dehydrates the core of the product, helping to preserve it. Other industries also benefit from salt's properties. organic chemistry and pharmaceuticals, for example, use salt to separate fats and oils.

What are the organoleptic properties of salt?

R.H.: What's interesting about salt is that it feels more or less salty, depending on the size and shape of the crystals, rather than on taste. A blind tasting of different salts would yield few conclusive results. On the other hand, surface effects really do give the impression of different tastes. Fleur de sel and its crisp mouthfeel can create a certain emotion. An ice salt will provoke something different. The finer the texture, the more flavor.

Three questions for François Perret, head pastry chef at the Ritz Paris

Gault&Millau: What is your approach to salt in pastry-making?

François Perret: Salt isn't just for cooking, just as sugar isn't just for pastry-making. I think it's a shame to use sugar without a hint of salt. The important thing in pastry-making is to create a balance of "just the right amount of sugar". You play with it, even challenge it. This can be done with the acidity of a fruit, the bitterness of a product like chocolate, or by counterbalancing it with salt. It's important to remember that sugar isn't just a seasoning, it's also a structuring agent. A meringue without sugar doesn't work, but when you add a few grains of salt, the dessert sensation is disrupted, yet more complete. The idea isn't to hide excess sugar, but rather to temporize the sugar you're obliged to add. Fleur de sel, for example, cuts the sensation of fat, disrupting the palate a little and blurring the message of sugar.

What type of salt do you like to use?

F.P. : Mainly fleur de sel. Maldon salt has very fine crystals, like dew that has frozen. Fleur de sel awakens the taste buds and creates gustatory excitement. It is particularly striking on apple pie, or in combination with roasted cocoa and pepper, or in Swiss bread with bitter dark chocolate. Seasoning gives rhythm to the tasting. For me, there really are no rules: the only limit is the balance of tastes.

what do you think makes a good salt?

F.P.: A fleur de sel with a slightly moist texture and crystals that are neither too large nor too hard, otherwise it sticks to the tooth and the tasting experience can be ruined. Fine crystals, not necessarily white or pure, and, if possible, a French fleur de sel, since there's a rich tradition and high-quality products. It would be a shame to miss out.