By Kim Robson
Salt is so common and ubiquitous that we hardly think about it anymore, except perhaps to wonder if we consume too much of it. But not very long ago, before modern mining and drilling methods were developed, salt was one of the world’s most important commodities. Bags of salt rocks were carried by camel along the ancient spice roads of the Middle East. It was hoarded, hidden and used as currency. Salt allowed the Vikings and other early explorers to discover the new world because they could carry preserved salt fish for long distances. It has established cities, provoked and financed wars, secured empires and inspired revolutions (remember Gandhi walking to the salt marshes of Dandi?).
The only rock we eat, salt is essential for human survival. In fact, all mammals need salt. That’s why we find animal trails that lead to natural brine pools and salt licks. The word “salt” is a chemical term for the substance created by a reaction between an acid and a base. Of the many different types of salts, the one we like best, sodium chloride, comes from sodium, an unstable metal that likes to suddenly burst into flames, and chlorine, a deadly poisonous gas. Together they form NaCl, or table salt.
Salt is critical for digestion and respiration. Without it, the body cannot transport nutrients or oxygen, or transmit nerve impulses or move muscles, most especially the heart. This is why sports drinks contain electrolytes, which are soluble salts, to help keep the heart pumping and muscles from seizing up. Baby formula contains three types of salt: magnesium chloride, potassium chloride, and sodium chloride. Escapees from Soviet Russia’s brutal Gulag system would take life-saving salt tablets with them out onto the barren Kazakh steppes.
An average-sized adult person has more than 250 grams of salt in his/her body, enough to fill three or four shakers. But since we can’t manufacture salt naturally, we’re constantly losing it through bodily functions. We need to replace that lost salt because, without both water and salt, cells die of malnourishment and dehydration.
Salt also has countless practical and industrial uses, including but not limited to preserving foods, making ice cream, making boiled water hotter, removing rust, functioning as a cleaning and scouring agent, putting out grease fires, melting road ice, manufacturing pharmaceuticals, fertilizing fields, making soap, dying textiles, softening hard water; and treating indigestion, sprains and sore throats.
The debate among nutritionists and scientists about how much salt people need continues. Estimates vary wildly, from two-thirds of a pound up to 16 pounds annually. Those who live in hot, humid climates, or who do a lot of heavy physical labor will need much more salt to replace that lost to sweating. West Indian slaves were fed salted cod for this reason. But red meat eaters who don’t sweat excessively don’t require nearly as much salt. Cultures of meat eaters such as the Plains Lakota Indians, and East Africa’s Masai, appear to get all the salt they need from animals’ blood and meat. But vegetarian diets, rich in potassium, offer little natural salt.
It seems that hunter-gatherer tribes did not make or trade for salt, but agricultural tribes did. Throughout history and around the world, when humans began cultivating crops and raising livestock, they also began looking for salt to add to their diets. Domesticated livestock needs to be fed salt. A horse requires five times as much salt as a human; a cow needs up to ten times as much. Ice Age Mongolians observed reindeer approaching encampments to drink the human urine there. They discovered that if salt was provided for the deer, they could be somewhat tamed and used as a source of food.
How we learned that we need salt is something of a mystery. Victims of starvation feel hunger; those with dehydration feel thirsty. Salt deficiency causes headaches, muscle weakness, light-headedness, and then nausea. Eventually the person will die. But at no time does the victim feel a craving for salt. However, most people eat more salt than they need – we simply like the taste of salt – and this urge may be a natural evolutionary defense.
After reading the excellent and utterly fascinating book Salt, by Mark Kurlansky, I had to get some interesting salt. I’ve long used Morton’s Kosher for everything. By the way, kosher salt doesn’t contain added iodine, which many gourmets believe adds a chemical flavor. First, I hit a feed store and got a large natural salt rock to set outside for the deer to lick. It’s a deep pink color, and the deer seem to just love having it around.
Then I ordered some gourmet salts from The Spice Lab. Got a kilo of Himalayan Pink in large rocks, just because I love rocks. They’re about 250 million years old and full of beneficial minerals missing from table salt. The rocks are much too big for a spice mill, so I have two options: I can grate a fine powder over food with a microplane, or I can make fleur de sel by putting a rock in a small dish with a bit of water. This method is much more fun.
Set the dish on a windowsill where it’ll get sun and, even better, a breeze. When the water has evaporated, scrape the salt crystals off the rock and the dish into another small bowl. The crystals might grow over the edge of the dish, too. Let the damp crystals dry thoroughly in the bowl, then break them up and store in an airtight container. With two rocks, I can get a couple of tablespoonfuls a day. I love the pale pink color.
Also got some Persian Blue rock salt. One of the oldest and rarest salts known to mankind at 560 million years old, it’s extracted from a salt mine in the northern province of Semnan in Persia. The intriguing blue color occurs during the forming of the salt’s crystalline structure, as intense pressure from the mountains above is exerted on the salt deposits. The individual crystals refract the light in an unusual way, resulting in a blue optical illusion, much like blue glacier ice. It looks gorgeous in a clear salt mill.
There are many, many more varieties of salts to try from all around the world. They come in every color of the rainbow. Have some fun and experiment with a kitchen staple we never gave very much thought to!