Published September 1, 2002. From Cook's Illustrated.
Food magazines and celebrity chefs are touting the flavor of gourmet salts that cost up to $36 per pound. Do they really taste better?
Step into just about any gourmet shop and you will find sea salts from around the world in a variety of colors and textures. Most are pricey, up to 100 times the cost of table salt. We wondered if a pinch here or a smidgen there is really worth $36 a pound. Will your biscuits or steak taste better if you spend more money on salt?
And what about choosing an everyday salt for adding to pasta water or chicken stock? More home cooks are following the lead of chefs and keeping kosher salt (rather than table salt) next to the stove. Chefs have spread the word that these oversized grains of salt have a pure, clean flavor and that it's much easier to pick up these large crystals with your fingers. While the argument about crystal size is persuasive, we wondered if kosher salt really does taste better than table salt.
Salt is either mined from ancient seas that dried up millions of years ago or obtained by evaporating seawater. In their pure form—sodium chloride—salts from both locations taste the same. What distinguishes one salt from another in color and flavor are the type and amount of minerals (such as magnesium, calcium, and potassium) and/or clays attached to the crystals of sodium chloride. The size and texture of the crystals—whether big flakes, irregularly shaped large grains, or regularly shaped small—are largely determined by the way the salt is processed.
What is referred to as sea salt is obtained from seawater held in large, shallow ponds or large pans. As the water evaporates, coarse crystals of salt fall to the bottom. The crystals are then collected by raking. Some sea salt is made from seawater that is artificially heated. This process produces relatively large flakes. The white fleur de sel, or "flower of salt," is harvested by skimming off the thin film of salt that forms on the surface of the pans. As a result, it is extremely expensive. (The brand we tested costs $36 a pound.)
Table salt is usually obtained by pumping water into an underground salt deposit to dissolve the salt, pumping the brine to the surface, settling impurities, and vacuum—evaporating the clear brine. Rapid vacuum evaporation yields the tiny, regularly shaped grains that fit through the holes in a salt shaker. Some table salt is taken from the sea and then processed by vacuum evaporation to yield small crystals.
Kosher salt can be mined or harvested from the sea. Processing is designed to produce coarse, irregular crystals that will cling to meat for the purpose of koshering, in which the salt is applied to draw blood and juices out of just-butchered meats. Kosher salt is manufactured under rabbinical supervision, which, along with the large size of the crystals, is what distinguishes kosher salt from most other salts, especially table salt.
Unlike kosher salt and sea salt, most table salts contain additives. Iodized table salt contains potassium iodide, which protects against thyroid disease. Dextrose may be added to help stabilize the iodine, and calcium silicate or one of several other drying agents are often added to prevent caking. Many chefs claim these additives can impart an off flavor.