Sea Salt

The oldest seasoning

Sea salt is one of humanity’s oldest harvested foods — produced by evaporating seawater for at least 8,000 years. Archaeological evidence shows large-scale salt production at coastal sites from Bronze Age Mediterranean to ancient China to pre-Columbian Mexico.

Salt was so essential to ancient civilizations that it functioned as currency — Roman soldiers were sometimes paid in salt (giving us the word “salary,” from Latin salarium). Salt taxes were major revenue sources for medieval European states.

Three production methods

Sea salt is harvested in three main ways:

• Solar evaporation (most traditional) — seawater pumped into shallow pools, evaporated by sun and wind over weeks/months
• Boiling/heated evaporation — seawater boiled to crystallize salt; faster but more energy-intensive
• Cold evaporation (modern industrial) — seawater frozen, removing fresh-water ice and concentrating salt

Each method produces salt with slightly different mineral profiles and crystal structures. Traditional solar-evaporation salts retain more trace minerals; industrial salts are typically purer sodium chloride.

Regional specialty salts

Around the world, traditional salt production has developed distinct regional products:

• Fleur de sel (France) — flaky thin crystals harvested from the surface of evaporation pools by hand; finishing salt
• Sel gris (France) — grey-tinged French salt, less refined, more mineral-rich
• Maldon sea salt (England) — pyramid-shaped crystals, prized for their crunch
• Hawaiian alaea salt — red salt mixed with iron-rich volcanic clay
• Hawaiian black lava salt — black, mixed with activated charcoal
• Korean bamboo salt (jukyeom) — sea salt packed into bamboo and roasted multiple times
• Himalayan pink salt — actually mined from ancient sea-bed deposits, not modern sea salt
• Persian blue salt — naturally blue mineral salt from Iran

Each has its devotees and its specific culinary applications.

Iodine considerations

Most sea salt is not iodized — unlike table salt, which has iodine added to prevent goiter and other thyroid disorders. In regions where iodine deficiency is common, exclusive consumption of sea salt could lead to mild iodine deficiency.

This is generally not a concern for people eating diverse modern diets including seafood, dairy, and fortified products. But the issue does occasionally come up in dietary recommendations and nutrition discussions.

Microplastic problem

A 2018 study found microplastic particles in over 90% of commercial sea salts sampled worldwide — reflecting the increasing plastic pollution of ocean waters. The amounts are small (typically dozens to hundreds of particles per kilogram), and the health effects of microplastic consumption are still being researched.

Some specialty producers have begun marketing microplastic-free sea salt harvested from particularly clean sources or filtered during production. The microplastic finding has driven some consumers toward Himalayan or other mined salts as alternatives.

A flavor difference

Beyond the dietary considerations, sea salt actually tastes different from refined table salt:

• More complex flavor (trace minerals contribute)
• Different crunch (larger irregular crystals vs uniform fine grains)
• Slightly less harsh on the tongue
• More nuanced in finishing applications

For cooking, the differences are subtle but real. For finishing — sprinkling at the table — the differences become more pronounced, and serious cooks often keep multiple salts for different uses: kosher salt for cooking, fleur de sel for finishing, smoked or specialty salts for accent.