Whether referring to kosher salt, sea salt, table salt or Himalayan salt, anyone who eats out at a restaurant is talking about a material that’s more than 99% sodium chloride. The main differences lie in its size and texture, as well as the color and crystal clear trace minerals it contains. Kosher sea salt is harvested from sea waters harvesting locations in six different nations: Israel, Austria, Bulgaria, Czech Republic, Denmark, Estonia, Finland and Norway. The largest source of kosher sea salt comes from the Dead Sea, which is believed to be one of the world’s largest concentrations of salt mineral deposits. Other sources include Belgium, Germany, the Netherlands, Poland, Romania, and the United Kingdom.
Kosher sea salt is harvested by lifting sea water from the sea bed and then dissolving it within the sea salt’s tank. As it dissolved, the magnesium and iron minerals of seawater are carried away with it, leaving behind an oily film on the surface called marine grade. This film makes the sea salt more absorbent, thus it is used as a table salt. The higher the percentage of magnesium and iron contained in the seawater, the more it will absorb. Table salt cannot be used as a table salt without being processed with a mineral sea salt formula and must instead undergo a special procedure known as “ozonation.”
Zoned sea salt is any salt that contains a higher percentage of sodium chloride than natural sea salt. Most table salts are processed to get to these levels, but “refined” does not always mean “precious.” “refine” means that the impurities have been removed, but the overall composition of the salt is not changed. Oceanic and fresh sea salts can both be “refined,” though in different ways.
Oceanic sea salts that were harvested usually contain fossils, oyster shells, and other sea creatures. Many such salts also contain magnesium, iron, and trace minerals. Salt works best when it has been harvested from sea water that contains sufficient dissolved oxygen to permit natural convection to kick up a bout of surface moisture and to keep the molecules close enough for them to crystallize and form into salt. Salt works best in alkaline water, which happens to be the majority of the ocean’s water.
“Kosher” table salt is not actually kosher in the strictest sense, as there is no kosher certification for the harvesting of this kind of salt. However, kosher salt is not harvested with the same method as sea salt (which is technically kosher), and the kosher classification applies mostly to the surface layer of the salt. In general, kosher salt is a lot less expensive than sea salt. Some kosher table salt products do use kosher salt flakes, but these flakes tend to be quite small, so they do not clog pores as easily as regular table salt would.
Irrespective of whether you use sea salt or table salt in your cooking, there are inherent differences between the two that you have to be aware of. Sea salts are harvested using a method that looks a lot like harvesting terrestrial salts. But unlike terrestrial salts, sea salt is harvested by opening the stone and extracting the precious salt from the interior of the stone, which requires breaking the stone open, pouring the saltwater inside, and then filtering the liquid through fine mesh screens. This process also tends to strip the natural minerals from the mineral, which diminishes their effectiveness. Sea salts are also more expensive than table salts.
Table salt is harvested by spinning natural rock to remove the bulk, which includes any silica or magnesium that may be present. This leaves behind a thin film of magnesium and silica that has trace amounts of both minerals. These minerals are then mixed with laboratory minerals that can add up to about 50 percent more of those trace minerals to the salt. The end result is a product called sodium chloride, which has trace amounts of calcium, potassium, and magnesium; just right for seasoning food and for many other applications.
One important distinction between sea and table salt is the texture. Salt rocks harvested from the sea tend to have a duller and coarser texture, while table salt tends to have a clay-like texture, which some experts find to be better for food flavor. However, this difference doesn’t seem to be enough to justify giving a preference to one over the other. Many enthusiasts have a preference for one over the other, and many will claim a particular salt’s texture is a matter of personal preference, though others will argue that it comes down to the individual’s taste and point of view. Ultimately, all you need to decide is which type of texture will best meet your needs.