Table salt, sea salt, kosher salt – what's the difference?
February 16, 2005
QUESTION: What is the difference between sea salt, kosher salt and good old sodium chloride? I always thought that NaCl was salt, period.
P.E., San Diego
ANSWER: Chemically speaking, a salt is any combination of an anion of an acid and a cation of a base. This means that not every salt has to contain sodium. Calcium carbonate, the calcium compound in foods and some dietary supplements, can also be considered a salt.
In non-scientific food discussions, however, the term salt or table salt commonly refers to sodium chloride, the familiar white granular seasoning.
Sea salt comes from evaporated seawater. The mineral content of sea salt is not limited to the sodium and chloride that make up the traditional salt molecule. Additional minerals can give the salt subtle flavor characteristics that can enhance foods.
I was initially skeptical that sea salt had special qualities, but I changed my mind when I did a blind tasting of salts while in Italy. The experience was enough to induce me to keep some sea salt on my shelf for cooking.
Depending on the brand, table salt can contains a small amount of an additive to prevent caking and encourage a smooth flow. This is often silicon dioxide, the primary ingredient of sand. It is not absorbed and has GRAS (generally regarded as safe) status as an additive. If the table salt is iodized, a source of iodine also will be added.
Kosher salt is pure sodium chloride, usually without any additives, and it often comes in coarse crystals. It is not necessarily a kosher product, but it can be certified as kosher for Passover use. The real connection is that kosher salt has been used in the process by which foods are made kosher. It is no better or worse than any other form of table salt. I hope this helps clear up the differences.
Salt has played an integral yet largely unappreciated role in history. Those interested in learning more can read "Salt: A World History" by Mark Kurlansky (Penguin).