Salted_ A Manifesto on the World's Most Essential Mineral, With Recipes - Mark Bitterman [37]
Cyril Osborne making Maldon salt with his son Clive.
SOLAR-FIRE HYBRID SALTS
One way to decrease the amount of fuel needed to evaporate salts is to preconcentrate the brine by solar evaporation. Because many fire crystallized salts are made in damp, cool climates, a greenhouse is usually used in lieu of open air evaporators, and then the concentrated brine is crystallized in a vat over fire. The solar pans, whether indoors or out, concentrate the brine to precipitate out unwanted salts and minerals such as the sulfates and carbonates, then the brine is further concentrated until it has the mineral profile desired by the salt maker. This conditioned brine is then fed into open cauldrons or pans and heated very slowly, usually by wood fire, to assist the formation of crystals. Many such salts are hand stirred—or even hand massaged! (see Temomi Tenpien Enmusubi)—to aid in the uptake of magnesium and potassium (the salts that remain after the crystallization of NaCl, known as nigari) into the crystals of sodium chloride and other salts. Many of the great Japanese artisan salts are made this way.
What was probably the most common and ancient way to create a condensed brine was to extract it from sand or dirt. Sands or soils in salt estuaries or swamps that drain seasonally or with the tides can be scraped up and mixed with any available water. Ocean water could be sprayed or poured over clean beach sand and evaporated in the sun, then washed out with more salt water. Inland soils naturally high in salt can be soaked in fresh water. These brines can then be filtered and boiled off over a fire to crystallize salt.
For most of human history this was probably the method practiced across the widest variety of geographical domains. Today, it is mostly the salt of last resort practiced in the most impoverished parts of the world, though Okunoto Endenmura is an ancient salt still made in Japan made the process of “shio maki,” casting sea water over the sand covered salt fields and “kama taki,” boling down the brine in a kama or pot to achieve optimal concentration and crystallization. The result is a magnificent artisan salt that communicates a samurai’s fury and discipline.
FLAKE SALTS
Pure sodium chloride crystallizes in sharp, defined faces, which, in a perfect environment, grow into dauntingly large, sharp-edged cubes. The more uniform the salt crystal, the harder it is. A jumbled, highly irregular crystal has a much more pleasant crunch than a uniform crystal. A moist crystal is more yielding than a dry one. The softest crystals of all, such as fleur de sel and sel gris, are both jumbled and moist, and can seem downright unctuous. But salt’s natural tendency to form in cubes can produce an entirely different category of crunchable salts: flake salts. Instead of granular, irregular crystals, flake salts have plate-like (lamellous) crystals that are dry, thin, and brittle—so brittle that even the largest flake salt seems to pop into a million pieces if you so much as look at it the wrong way.
Flake salts are basically the skeletons of much larger crystals that form when the faces of the crystals have a different growth rate than the edges. This can occur for a variety of reasons, and can result in crystals like pyramids or extraordinary hollow-faced boxes. I have found pyramidal crystals larger than a silver dollar. Many of these hollow crystals are crushed during crystallizing, harvesting, and packaging, resulting in flakes.
Salt can form into flakes in carefully regulated boiling water, or in the sheltered