Before refrigeration, most food was heavily salted. Many of these salted foods have persisted, such as sauerkraut, pickles, cured anchovies, cheese, salted butter, ham, corned beef, sausage, and bacon. We still eat these things because we like them. But they are no longer the mainstay of our diet.
I always wanted to write a book about a common food that becomes a commercial commodity and therefore becomes economically important and therefore becomes politically important and culturally important. That whole process is very interesting to me. And salt seemed to me the best example of that, partly because it's universal.
Things that become important to economies become ritualized and become deified. Because I'm Jewish, I always thought it was interesting that in Judaism, salt seals a bargain, particularly the covenant with God. Some people, when they bless bread, they dip it in salt. Same thing exists in Islam.