Sea Salt Explained: Why You Float in the Dead Sea and How Salty Water Works

Sea salt is the salt obtained by evaporating seawater, and it is far more than ordinary table salt: it carries a natural blend of sodium chloride together with trace minerals such as magnesium, calcium, potassium, bromides and iodine. These dissolved substances raise the density of the water they come from and give sea salt its distinctive flavour and mineral character. The story of sea salt runs from the ancient shorelines where people first scraped crystals from drying pools to today's gourmet finishing salts prized in professional kitchens.

What is sea salt?

Sea salt is a natural, largely unrefined salt produced when seawater evaporates and leaves its dissolved minerals behind. Unlike heavily processed table salt, which is refined down to almost pure sodium chloride and treated with anti-caking agents, sea salt keeps a portion of the naturally occurring trace minerals and electrolytes present in the ocean. That difference in composition is why sea salt appears in so many forms — coarse crystals, fine grinds and delicate flakes — and why cooks treat it as both a seasoning and a finishing ingredient rather than a single generic commodity.

Salt has shaped human commerce for thousands of years. Production dates back to at least 6000 BC, and the mineral was once so valuable that the Ancient Romans used it as a medium of trade and payment. Today the same substance is harvested at scale for agriculture and industry, yet the artisan, hand-harvested end of the market has grown into a distinct gourmet seasoning-salt category.

Why doesn't a person sink in salt water?

A person floats in very salty water because the dissolved salt raises the water's density, and denser water pushes back on a submerged body more strongly. Looking at a striking magazine photograph — a man lying on the water without a swim ring, calmly reading a newspaper — you naturally ask why he does not sink. The caption answers it: "In water with a high specific gravity, even someone who cannot swim will not go under." The picture was taken on the Dead Sea, where the salt of the sea greatly increases the density of the water.

Archimedes' principle and the density of salt water

Archimedes' principle explains the floating: any body immersed in a liquid is pushed upward by a force equal to the weight of the liquid it displaces, so denser liquid produces a stronger upward push. Dissolved substances increase the specific gravity of water. A litre of water from the Dead Sea weighs almost 1,200 grams — about 200 grams more than ordinary water. Because that heavier water displaces more weight for the same volume, a person can lie on its surface and stay afloat much like oil or a slab of ice.

The Dead Sea

Why the sea is called "dead"

The Dead Sea earns its name because neither plants nor animals can live in its water. When specialists analysed this death-bearing water they found that near the surface it holds 21.7 percent dissolved salt, while at the bottom it resembles a saturated brine. That concentration is many times greater than any ordinary ocean, which is why living organisms cannot survive in it.

The Dead Sea's mineral salt reserves

The Dead Sea holds more than 20,000 million tonnes of valuable mineral salt, used in agriculture as fertiliser. Because of this enormous store, potash-extracting companies that draw on the salty water of the Dead Sea occupy a near-monopoly position on the world market for these minerals.

Where does the salt in the sea come from?

The salt in the sea is carried there by water flowing off the land. "Where does the salt in the sea come from?" is a question people ask often, and the answer lies in the constant journey of water through soil and rivers.

For a long time it was believed that seawater simply dissolves salt deposits that had lain on the sea floor since the Earth was forming. But that only pushes the question back a step: how did the salt get into those ancient seas in the first place? We know that a raindrop dissolves mineral substances as it passes through the ground, feeding salty water into mineral springs, and that a river such as the Rhine carries salt down to the sea.

The role of groundwater and river water

Both observations point to the correct answer: groundwater dissolves the salts held in the soil and in riverbeds, and the flowing rivers carry them out to sea. Over vast stretches of time these dissolved minerals accumulate because water evaporates from the ocean surface while the salt stays behind. It is no surprise, then, that seawater contains not only salts but other minerals as well — even gold and uranium. The "gold reserve" of the world ocean has been estimated at around 8 million tonnes.

The composition of seawater

The salt content of seawater varies widely from one body of water to another. The water of other large inland seas is far less salty than the Dead Sea: the Caspian Sea holds only about 1.4 percent salt, and the Baltic Sea even less.

Salt content in different seas and oceans

Ocean water carries about 3.5 percent salt on average, which means that one cubic metre of seawater contains roughly 3.5 kilograms of salt. Besides pure common salt (sodium chloride), the water also holds bitter salts (sulphates) and small amounts of bromine and iodine salts (carbonates and bromides) that give the water its bitter taste. This mix of dissolved compounds is exactly what makes evaporated sea salt richer in trace minerals than refined table salt.

Minerals, gold and uranium in seawater

Seawater is effectively a dilute solution of nearly every element found on Earth. Alongside sodium chloride it holds magnesium, calcium and potassium compounds, and in vanishingly small concentrations even precious and radioactive metals such as gold and uranium. The quantities per litre are tiny, but across the whole ocean they add up to enormous figures — the estimated 8 million tonnes of dissolved gold being the most famous example.

Methods of harvesting sea salt

Sea salt is harvested chiefly by letting the sun and wind evaporate seawater, though ancient deposits and caves are also mined. The two approaches — solar evaporation of fresh seawater and extraction of salt laid down by long-vanished seas — supply most of the salt used for cooking and industry today.

Evaporation in shallow bays

The method of solar salt-making is extremely simple. Seawater is channelled into shallow lagoons or bays, where the hot southern sun evaporates it quickly, leaving the salt behind on the floor of the pond. Salt is produced this way in many countries around the Mediterranean, and the same principle underlies the artisan salt pans of France, Sicily, Australia, New Zealand, South Africa and Brazil.

Harvesting salt from ancient deposits and caves

Some of the finest mineral salts are not evaporated from today's oceans at all but mined from the dried beds of prehistoric seas. Himalayan Pink Sea Salt, for example, is quarried from ancient marine deposits in the Himalaya Mountains region straddling Pakistan and the Himalayas, where it has been protected underground for millions of years. Cave-harvested salts such as Celtic Pink Cave Salt are drawn from similar sealed deposits, and because they never came into contact with modern pollution they are prized as all-natural, unrefined salt without chemical additives.

Types of sea salt and their origins

Sea salt comes in a wide range of varieties defined by where the seawater was gathered and how the crystals were formed. Producers around the world have built distinct product lines, from the pyramid-shaped flakes of Maldon in England to the moist grey crystals of Celtic Sea Salt® in France and the pink mineral salts of the Himalayas.

Well-known gourmet sea salt varieties include:

• Maldon Salt — hand-harvested from seawater drawn off the Blackwater Estuary near Maldon in Essex, England, and famous for its hollow pyramid crystals.
• Celtic Sea Salt® — a French mineral-rich salt sold in forms such as Light Grey Celtic®, Celtic Fine Ground™, Celtic Kosher™, Fleur de Sel Sea Salt, Makai Pure® and Celtic Pink Cave Salt, popularised by Jacques Delangre and Selina Delangre.
• Himalayan Pink Sea Salt — mined from ancient deposits, coloured by its trace-mineral content.
• Fleur de Sel — the delicate top-layer "flower of salt" skimmed by hand from evaporation ponds in France.
• Sicilian Sea Salt and Tidman's Natural Rock Salt — traditional Mediterranean and rock-salt options.

Maldon Sea Salt and its traditional artisan production

Maldon Salt is made by boiling filtered seawater from the Blackwater Estuary in shallow pans until soft, hollow pyramid crystals form on the surface, which are then raked off by hand. The company has been run by the Osborne family for generations — figures such as Cyril Osborn, Clive Osborn, James Osborn and Steve Osborn are associated with its heritage — and its signature pyramid flake is the reason chefs reach for Maldon as a finishing salt. Compared with table salt, which is machine-produced and refined to uniform grains, Maldon Sea Salt keeps an open, crunchy texture and a clean, briny flavour that dissolves cleanly on the tongue.

Grain size and texture (coarse, fine, flake)

Sea salt is categorised largely by grain size and texture, and each type suits a different job in the kitchen:

• Coarse salt — large, hard crystals ideal for salt grinders, brining and crusting; salt grinder refills are usually coarse.
• Fine ground salt — dissolves quickly and measures evenly, making it the everyday choice for baking and general seasoning.
• Flake salt — thin, brittle crystals such as Pure Flake Finishing Sea Salt, Kosher Flake Sea Salt and Maldon's pyramids, used as finishing salts and coarse salts that add crunch and a burst of flavour on top of a finished dish.

Flavour and sensory characteristics

Sea salt tastes cleaner and more complex than table salt because its trace minerals soften the sharp, purely saline edge of sodium chloride. The flavour profile changes with origin: grey Celtic salts carry a moist, briny minerality, Fleur de Sel is subtle and slightly sweet, and Himalayan pink salt has a mild, rounded taste. Texture is part of the sensory experience too — a flake dissolving on the palate delivers salt in bright bursts rather than a flat, even saltiness.

Comparison of sea salt types and origins

Flavour-infused salts extend the range still further. Producers such as the Prince William Sound Salt Company, which draws pristine seawater from Prince William Sound in Alaska, and gourmet sellers on platforms like Etsy offer smoked, citrus, herb and spiced blends — Alder Smoked Sea Salt, Salish Alder Smoked Sea Salt, Bacon Smoked Sea Salt, Black Truffle Sea Salt, Garlic Truffle Sea Salt, Roasted Garlic Sea Salt, Chili Lime Sea Salt, Lemon Twist Sea Salt, Rosemary Lemon Sea Salt and Fresh Lemon & Lime Flake Sea Salt among them. Small-batch, hand-harvested lines like these are typically sold in tins, grinder refills and gift sets such as the Sea Salt Vial Gift Box, at premium prices reflecting their artisan production.

Culinary uses of sea salt

Sea salt is used to season, finish, preserve and cure food, and the form you choose depends on the task. Fine grinds season during cooking and baking, coarse crystals brine and cure, and flake salts finish a plate at the last moment. For centuries salt has also served as a preservative, drawing moisture out of fish and meat to keep them safe long before refrigeration existed.

Chef endorsements and use in professional kitchens

Professional chefs favour premium flake salts because they can be pinched and sprinkled precisely, giving control over seasoning that pouring from a table-salt shaker cannot match. Maldon Salt in particular is a fixture in restaurant kitchens and has been featured by food media and creators including Delish, Sorted Food and cooking channels on YouTube. Its clean flavour and crunchy pyramid crystals make it a standard finishing salt for grilled fish, roasted vegetables and even desserts.

Pairing with fish and seafood

Flaky finishing salts and mineral-rich sea salts pair especially well with fish and seafood, where the goal is to lift the natural flavour without overwhelming it. Establishments built around seafood illustrate the pairing well: a Maine lobster shack such as the Sea Salt Lobster Restaurant, which opened as a fresh-never-frozen seafood concept, uses good finishing salt on Lobster, Crab, Oysters, Clams, Mussels and Scallops. Wild Alaskan seafood is a natural partner too — a light flake of hand-harvested salt finishes salmon and halibut beautifully, and complementary flavours from smoked or citrus salts echo the character of grilled fish, Haddock included. If you enjoy pairing salt with the day's catch, a trip focused on fishing makes the freshest possible starting point.

Citrus zest infusion

Citrus-flavoured sea salts are made by blending flake salt with dried Lemon or Lime zest, capturing bright, aromatic oils in the crystals. Products such as Lemon Twist Sea Salt, Fresh Lemon & Lime Flake Sea Salt and Rosemary Lemon Sea Salt bring an instant lift to grilled fish, roasted vegetables and salads, and coarse citrus salts are also popular for rimming a margarita glass. You can create a similar infusion at home by rubbing fresh zest into flake salt and letting it dry.

Health effects and benefits of sea salt

Sea salt supplies sodium and trace minerals the body needs, but its health benefits over table salt are modest and its risks come mainly from consuming too much. Sodium helps regulate hydration, blood pressure and muscle function, yet the difference in mineral content between sea salt and table salt is small once you account for typical serving sizes. It is worth being clear that the scientific evidence for many popular "mineral salt" health claims is limited.

Effect on digestion

Sea salt contributes to healthy digestion mainly by providing the sodium chloride the stomach uses to make digestive acids and by supplying electrolytes that support fluid balance. Some people find unrefined sea salt gentler than heavily processed table salt, but the practical difference for digestion is minor; a balanced diet matters far more than the type of salt on the table.

Effect on the heart and blood pressure

All salt is essentially sodium chloride, so sea salt affects the heart and blood pressure in the same way table salt does when eaten in the same amount. Excessive sodium consumption is linked to high blood pressure and raises the risk of heart disease, and people with kidney disease are usually advised to limit salt intake closely. Choosing sea salt as a "lower-sodium alternative" is a common misconception — by weight its sodium content is comparable to table salt, though its flakes can mean you use less salt for the same perceived saltiness. Non-culinary home uses, such as a sea-salt bath to soothe skin irritation or eczema, are traditional remedies; organisations like the National Eczema Foundation caution that such measures relieve symptoms rather than cure the condition, and the underlying research remains limited.