Salted_ A Manifesto on the World's Most Essential Mineral, With Recipes - Mark Bitterman [73]
SHIO
Aguni Koshin Odo
ALTERNATE NAME(S): Koshin Odo Aguni; Aguni no shio; Aguni salt MAKER(S): Koshin Odo TYPE: shio CRYSTAL: very fine, fullerenelike composites; highly irregular COLOR: winter-moon white FLAVOR: sweet; elusive; cucumber MOISTURE: moderate ORIGIN: Japan SUBSTITUTE(S): Shinkai deep sea BEST WITH: rare beef filet; sashimi; barely cooked vegetables like peas; long-cooked vegetables like ratatouille; pinched into a cup of coffee
Allow the lattice-shell structures of ever-diminishing geodesic shapes tumble from your fingers, glinting with razor definition too small to discern, minerals mimicking in silvered origami the preprotozoan sex life of cells. Close your eyes. There is texture, certainly. But your fingers can’t find it. They say the blind have more sensitive skin. Perhaps this salt is visible only to the sightless.
Tasting Aguni is similar to looking at it. Deprived of knowledge of the world, you might think the ocean tastes this way, but it doesn’t. Nothing of the wildness remains, none of the sinus-shaving turbulence. And yet the feeling is not calm either. Sprinkle it on steamed vegetables, liberally or sparingly, and you taste: vegetables, and steam, and the fork. Sprinkled on the tongue, you taste, of all things, your tongue! The flavor is a series of “nots,” a process of elimination. But not that either; it is The Process of Elimination.
Aguni Island is far enough away from the larger islands of Okinawa that the seawater from which Aguni Koshin Odo is made is free of pollutants. Water is pumped from the ocean up to the top of a thirty-three-foot-tall tower and allowed to trickle down the thousands of fine bamboo branches that hang from its ceiling. The water that reaches the reservoir at the bottom of the tower is pumped back to the top and allowed to trickle down the bamboo again. The tower’s perimeter is built of blocks with large perforations, which allow the sea breeze to blow through and start evaporating the seawater as it picks up subtle flavors from the bamboo. After about a week, the water sitting in the reservoir is a concentrate (kansui), about six times as saline as normal seawater. The kansui is then divided into two batches so that two different methods of evaporating the remaining water can be employed.
In the first method, which yields the majority of Aguni Koshin Odo produced, workers take round-the-clock shifts stirring the kansui with a long-handled wooden paddle in a wide, shallow pan (hiragama) over a low fire of driftwood and scrap wood. Wood is used instead of gas because, while it is more difficult to maintain a constant temperature with wood, wood generates a wavelength of radiation similar to that generated by the sun. The constant stirring and the shallowness of the hiragama allow for quick, even crystallization. After two days of this, when the crystals are well formed, the slushy solution is transferred to a dehydration tank, where the last of the water is slowly removed over four to five days. The longer the salt spends in this tank, the more nigari (bittern) will crystallize into the salt. Finally, the salt is pressed through sieves for two days to mature.
The second method takes longer but produces a more sought-after salt. The kansui sits in a shallow tank inside a greenhouse for solar evaporation. It takes anywhere from three weeks (in the summer) to two months (in the winter) for the salt to crystallize out. The salt made using this method is preferred by many Aguni salt fans for its larger crystals and subtle taste, but is not easily found outside of Japan.
ODO’S EXPERIMENT
We think of seawater as salt water, but when we think of salt, we think of just one thing: sodium chloride. In truth, the sea contains many salts—and many other things. Sodium chloride represents only about 78 percent of the mineral content of seawater, yet refined salt is very nearly