What is fleur de sel?
Artisan salt producers harvest their fleur de sel from salt saturated sea water. This saturation is obtained by letting the sea water follow a lengthy path through salt pans while the water evaporates and the concentration of salt multiplies by eight.
Some of the salt in the pans changes into crystals on the surface of the water forming a delicate crust. This is fleur de sel.
The crystals are collected by hand once a day, a time-consuming job with revenues as low as a few grams per square meter. On top of that, only during one month a year, from mid-July till mid-August, the circumstances are favorable for harvesting fleur de sel.
Therefore, because of its relative scarcity, fleur de sel is one of the most expensive salts.