Salted_ A Manifesto on the World's Most Essential Mineral, With Recipes - Mark Bitterman [30]
THE MINERAL BODY OF THE SEA
The sea (and many other saltwater bodies) are generally 3.2 percent to 4 percent saline. Salt springs can be much higher in salinity, as can some isolated inland seas; the Dead Sea is 33.5 percent saline and Lake Assal in Djibouti is 34.8 percent. At 40 percent, Lake Don Juan in Antarctica is the most saline body of water in the world, remaining liquid at temperatures below -22°F. The ocean has a 3.5 percent average salinity. About 99 percent of the salts that make up this 3.5 percent salinity are made from just eleven ions. Saltmaking techniques are designed to concentrate the optimum balance and combination of these and other ions to achieve the desired salt. In the case of industrially made sea salts, this can be 99.8 percent or higher sodium chloride. In a traditional sea salt, the number could be 85 percent sodium chloride or lower. Minerals of the salt are, in a sense, the unique imprint of the techniques with which a salt is made and the minerals of the sea from which it is born.
THE HARVEST
The type of solar salt produced is determined by harvesting techniques. Regardless of type, however, a chief benefit of salts made using patient, quality-oriented techniques is a high degree of heterogeneity of crystal formation. Within a single pinch is a universe of specks, cubes, flakey hoppers (flat, scale-like crystals), layered hoppers, pyramids, and fused conglomerates. Each minute crystal has an immense surface area, with crannies and crevasses harboring moisture and minerals. These variations in size and structure, combined with characteristic moisture levels and mineral contents, are the hallmarks of an excellent culinary salt.
Most artisan salts are harvested using only human labor and highly specialized wooden tools designed centuries ago. Bare feet are the traditional footwear of the salt harvester. Sel gris, fleur de sel, and flake salts can be harvested daily, while the harvest of traditional salt is more flexible: depending on conditions and the desired output, traditional salts can be harvested every several days, every several weeks, or perhaps just once per season.
Sel Gris
In general, sel gris is harvested by standing on the edge of a salt pan and pushing and/or pulling the salt toward the edge with a wooden rake, and then raking or shoveling the crystals out of the pan into a pile on the ladure to allow any lingering water to drain. The specific techniques for harvesting sel gris vary depending on the land from which the salt fields are made, the climate in which the salt takes form, and the design of the salt farm itself. The basalt-, sand-, or concrete-lined salt pans of the Mediterranean are very different from Brittany’s clay-lined pans. In the Philippines, a tile floor is laid over the rich, dark mud of the salt fields, and after a few good days’ harvests, salt crystals actually cement the tiles together to provide a hermetic barrier between salt and silt that makes raking a piece of cake (except for the fact that it’s well over 100°F under the blazing sun and each of the pans is producing hundreds of pounds of salt per day).
In Guérande and the other western France salt marshes, the silt and mud that naturally accrete there are removed until the beautiful porcelain clay beneath is exposed. Harvesting the heavy layer of sel gris crystallized on this clay bottom is delicate work. Tremendous precision is required to avoid disturbing the bottom or, worse, gouging it, and dirtying the salt. Standing barefoot on the galpont, the clay border of the salt pan, the paludier moves with balletic fluidity, raking the crystals to a round platform in the middle called the ladure, where the day’s harvest is collected. The paleness of sel gris will vary somewhat from