This unique salt is steeped in tradition and has a deep-rooted history going as far back as two millennia! Harvesting occurs along the coastal regions of France, using techniques that have been honed over centuries. Celtic salt harvesting involves carefully evaporating sea water from clay ponds using the sun and wind which allows the process to preserve vital minerals and gives the salt its distinct flavor, grey hue and mineral-rich content. This whole process really allows for the natural flavour to come through as no mechanical and chemical processes are used. Because the salt is only 71 to 74% of sodium chloride, compared to the 98% most other salts are, the rest of it is comprised of bio-available minerals and trace elements (calcium, potassium, magnesium, iron, manganese, sulphur, zinc, iodine and other nutritive elements). 
Sel de Guerande is hand-harvested on the Celtic sea coast in Brittany. It is a nationally preserved area and registered as a World Heritage Site. The salt is created by sun and wind evaporation and it is neither filtered nor cleaned thus it is free of pollutants from mechanical and chemical processes. This salt is composed of only 71 to 74% of sodium chloride (for comparison most of the other salts are 98% sodium chloride), (ref: Dr Brian Clement). The remaining percentage is composed of bio-available minerals and trace elements (calcium, potassium, magnesium, iron, manganese, sulphur, zinc, iodine and other nutritive elements), which is why it is grey!