Salted_ A Manifesto on the World's Most Essential Mineral, With Recipes - Mark Bitterman [38]
THE BITTERN TRUTH
Bittern, referred to in Japanese as nigari (as with the English bittern, nigari is derived from the Japanese word for bitter), is what is left over after all the water is evaporated from a seawater brine and most of the major sodium and calcium salts are crystallized. Bittern contains magnesium compounds and a variety of trace minerals. In nature, it occurs as thin flakes of mostly magnesium chloride, with some magnesium sulfate and other trace elements. Since it is highly water-soluble, it often appears in nature as a very viscous liquid or a paste.
Bittern is an important coagulant used in the preparation of tofu from soy milk, and it is also an ingredient in baby formula; these are its two primary industrial uses. In Japan, however, bittern has become the subject of a health-food craze that developed from the perceived nutritional benefit of bittern in salt. Bittern is sold as a white powder and also marketed in nigarisui, a popular Japanese version of mineral water with bittern added. It is believed to have one of three effects, depending on how it is used. If taken on an empty stomach or after exercise, it replenishes the body with minerals, especially if taken with citric acid. If taken during a meal, it limits the appetite. If sprayed on the skin, it cleans and softens, and reduces wrinkling while it’s at it.
Some believe bittern mutes our ability to taste sodium chloride and monosodium glutamate (MSG). It may also decrease our biological craving for salt, and perhaps MSG.
Evaporated bittern usually accounts for 7 to 9 percent of the original brine (sodium chloride accounts for 19 to 21 percent).
Japanese salt makers often slow-cook a brine in order to intentionally fuse the bittern into the developing salt crystals. Japanese salts are inclined to be very rich in trace minerals, largely because they include a relatively large proportion of bittern to the other salts: minerals commonly found in bittern besides magnesium are calcium, sulfur, potassium, iron, phosphorus, boron, silicon, lithium, and iodine.
QUARRIED SALTS
The first question I ask myself when something doesn’t seem to be beautiful is why do I think it’s not beautiful. And very shortly you discover that there is no reason —John Cage
Salt in its mineral or rock form is called halite, which derives from halos, the Greek word for “salt,” combined with lithos, meaning “rock.” Luckily for us, salt even in its purest form is soft, with a Mohs hardness of just 2.5 (about the hardness of a fingernail), compared to, say a hardness of 100 for quartz or 1,600 for diamonds. We can crush a salt crystal with our teeth provided it is small enough. Still, a solid crystal is fairly hard in biting terms. Rock salt deposits have been mined for far longer than we are ever likely to know. However, mining was probably the least common way of acquiring salt for most of human history. Most rock salt mines were likely discovered by hunters pursuing wildlife that had congregated around salt springs. The hunters would have had an easier time getting their salt by evaporating the spring water than by digging through solid rock to access underground deposits. The Hallein salt mines in present-day Austria were the site of salt-winning from salt springs using briquetase for 4,000 years before organized rock salt mining began there, around 600 BCE.
Mining for rock salt was nasty, dangerous work. Every hundred years or so, the salt