Salt comes in hundreds of varieties, flavors, even colors now. The home cook can find many of these at local grocery stores and even more at specialty shops and online. But, what is the difference? Why does table salt cost under $1 for a container and sea salt cost hundreds of dollars for an equal amount?
There is little difference chemically between edible salts. All are 97.5% sodium chloride or higher.
The difference lies in the processing of these salts and the origin.
Table Salt is mined from underground deposits. Calcium silicate is added as an anti-caking agent.
Table salt is made up of fine crystals, has a sharp taste and feels uniform in texture. The grain is so fine that 1 teaspoon of table salt contains more sodium than a tablespoon of sea salt or Kosher salt.
Sea Salt is obtained from evaporated seawater. It usually receives no processing, so there are many minerals present. These minerals can add to the flavor of the salt and can color the salt, sometimes pink, brown and gray. When these salts are cooked or dissolved, they lose their unique flavor, so are best used as a seasoning. These salts are usually expensive.
Kosher Salt is named for the process of "koshering" used in Jewish dietary law. Kosher salt contains no preservatives and can be mined like table salt or obtained from the sea or underground. It has large crystals which make is useful for preserving as it draws moisture out of meats. Kosher salt is not recommended for baking as the crystals don't dissolve without high moisture content. Usually, kosher salt if fine to use in cakes but not cookies or breads.