Back at Down Island Farm, they pump the seawater into a 76-by-12 evaporator, a building that looks similar to a greenhouse. The pump filters any sand, seaweed, or aquatic life (which they collect and feed to the chickens and peacocks) out of the water.
The evaporator is totally heated by the power of the sun; it can reach over 120 degrees inside! The heat causes the water to slowly evaporate, which can take anywhere from two and one-half to 10 weeks depending on the weather (hot and dry is optimal). As the seawater evaporates, the salt is left behind, slowly turning from clear to opaque to blotchy then solid, and forming piles of crumbly crystals. When a crust forms on top, it’s ready to harvest as finishing salt. Heidi and Curt gently rake the delicate sea salt crystals into pyramids and allow for a few more days of evaporation. Entering the evaporator again, Heidi and Curt collect the crystals in totes to bring inside for packaging or blending to make flavor blends.
275-gallon of seawater makes about 60 pounds of salt
MV Sea Salt produces two grades of salt – a coarse, natural grade known as “traditional” or “finishing” salt and sel gris, a more mineral-dense, moist salt. Flavor blends feature locally-grown ingredients. MV Sea Salt is more moist and tastes brinier than the sea salt you’d buy in a store. It tastes like Martha’s Vineyard. Really. It does. You can find ideas for using MV Sea Salt on our Sea Salt Recipe pages.