Robert L. Wolke, a food-science columnist for The Washington Post, clears up confusion about salt.
Q. Some recipes call for using kosher salt, often when rubbing directly onto meat. Can you explain the differences among kosher, “sea salt” and plain old salt? Do I really need to keep three kinds of salt in my pantry?
A. Salts do differ in physical form – in crystal size and shape – rather than in taste.
Commercial edible salts from the mine and from the sea are about 99 percent pure sodium chloride, though some sea salts might contain 1-2 percent of magnesium and calcium chlorides.
Sea salts are not “rich in essential minerals.” The crystallization process itself, whether by solar evaporation of seawater or vacuum evaporation of brine from a salt mine, is a purification technique that has been used by chemists for centuries.
Salt crystallized from seawater by slow solar evaporation develops larger, more complexly shaped crystals than rapidly crystallized mined salt. It is this coarser texture that elevates sea salts.
Cooking with sea salt is a foolish extravagance; the textural effect is gone as soon as the crystals dissolve. So when a recipe specifies “sea salt,” ignore it. Chefs know it’s best sprinkled on a dish just before serving.
Sea salts such as Hawaiian red salt and Indian black salt do have unique flavors: salt plus clay, which is what they are.
Kosher salt is a coarse-crystal salt used in koshering to coat meat to extract residual blood. Chefs use it because its crystals make it easy to judge amounts by pinching it from a dish.
So you do need three kinds of salt: kosher for cooking and seasoning; a coarse sea salt for topping meat, fish and vegetables; and regular table salt, the standard of measurement.
– The Washington Post
