What makes Kosher Salt, Kosher Salt is the fact that the salt itself must fit in accordance with the laws of the Old Testament, and the Talmud. The salt must be overseen and certified by a rabbi for it to be labelled Kosher and follow the strict set of guidelines outlined in those two texts. The salt would then be fit to eat for all Orthodox Jews after it is certified Kosher Salt by one of over 400 Rabbinical Supervision agencies in the U.S. alone.