Where Sea Salt Comes From: Evaporation Ponds, Salt Flats, and Salt Lakes

Sea salt is produced by evaporating seawater until only dissolved solids—primarily sodium chloride—remain. Three natural and engineered settings accomplish this:

1. Sea Salt Ponds (Solar Evaporation Ponds)

Shallow, diked basins in coastal zones. Seawater enters, sun and wind evaporate water over weeks/months. Salt crystallizes in stages: first calcium carbonate, then gypsum, finally halite (NaCl). Harvested mechanically or by hand. Traditional in France (Guérande), Portugal, Spain, California, Australia.

2. Salt Flats (Salars / Playas)

Natural depressions where groundwater or seasonal floodwater evaporates, leaving salt crusts. Some are ancient seabeds (Salar de Uyuni, Bolivia—world's largest). Others are active coastal flats (Bonneville Salt Flats, Utah). Harvesting ranges from artisanal to industrial.

3. Salt Lakes

Terminal lakes with no outflow. Inflowing water carries dissolved minerals; evaporation concentrates them until saturation. Examples: Great Salt Lake (Utah), Dead Sea (Israel/Jordan), Lake Assal (Djibouti). Salinity often exceeds seawater 5–10×, yielding distinct mineral profiles (magnesium, potassium, bromides).

Sea Salt vs. Table Salt

Sea salt retains trace minerals (magnesium, calcium, potassium) and irregular crystal structure, affecting flavor and texture. Table salt is refined to ~99.9% NaCl, often with anti-caking agents and iodine added.

All salt ultimately comes from the sea—some just took a geologic detour.