All Salt Is Not the Same

To answer these questions about good ol' NaCL, we have to trace salt production back to its origins. And for much of the salt we consume, those origins are in salt mines where the last remains of oceans evaporated in prehistoric times.

In hot spot locations around the world, these seabeds contain rock salt deposits that are procured by humans via salt mining. In some cases, a technique called solution mining is employed, by which rock salt is dissolved into water and then pumped to the surface.

The other leading source for salt deposits lies in our open oceans and salt lakes. Thanks to the natural process of solar evaporation, sea water dissipates in shallow ponds, leaving only the salt behind. From there, humans collect the salt brine and crystals with salt pans. These origin points play an enormous role in why salts have such varied tastes and uses.

While many of us think of it as a simple garnish, common salt is an enormous industry. From paper pulp mills and water treatment facilities to cosmetics and textiles, sodium chloride is a valued commodity. Of course, it's also a sensation in our foodie culture, where different salts offer unique taste profiles.

"The key components of flavor are taste, aroma, mouthfeel (e.g., texture + temperature), and what we term in 'The Flavor Bible' as the 'X Factor,'" Karen Page, author of "The Flavor Bible," said in an email. Her book (which she co-authored with Andrew Dornenburg) is a go-to index that helps chefs and other culinary professionals pair ingredients in dishes and meals.

Table salt — perhaps the most common variety — is also the most processed. It's mined, and either brought up as rocks (rock salt) or dissolved underground and then evaporated later. Table salt is treated to have fine grains and avoid caking. It's also often fortified with iodine, a chemical our bodies don't produce, which is essential for proper thyroid function.

But many food lovers skip table salt; some because they think the taste is altered by iodine and prefer kosher salt or sea salt. Kosher salt doesn't have any additives, and its name comes from the fact that it meets Jewish dietary guidelines. Kosher salt is also coarser than table salt.

There's a wide variety of sea salt, and flavors of salt vary based on where the saltwater is. Most grocery store sea salt is evaporated through man-made means, instead of naturally. But more expensive sea salts come from shallow ponds and salt pans that are allowed to evaporate naturally, and the salt crystals are harvested.

Salt from the top of the pans is usually white and neutral in flavor, such as "fleur de sel," or flower of the salt. Meanwhile, salt from the bottom of the pans usually has some color and more nuanced flavor picked up from the pan, such as "sel gris," or gray sea salt. Sea salt produced via natural evaporation can have a variety of textures. For example, Maldon Sea Salt, which comes from England's east coast, is known for its wide, flat, fragile, crunchy flake.

Mined salt also can have different colors and flavors based on where it comes from. For example, Himalayan pink salt comes from the Khewra salt mine in Pakistan, the second largest salt mine in the world. (It's also one of the oldest, as it's believed that Alexander the Great discovered Khewra salt mines in 320 B.C.E.) The pink color comes from traces of rust in the salt.

But, as author Page points out, there's more to salt's flavor than taste alone. "Texture is a key aspect of mouthfeel, which is often a function of the size of the salt grain," she said. "Very fine grains will 'melt' into a dish more easily, while crunchy, coarse grains will add texture to the dish. Think about how the coarse salt adds to the crunchiness and deliciousness of a hard pretzel."

The size of the salt grain also makes a difference in how the salt is used. Fine salt is more often used during the cooking process, while larger grain salt is sometimes used just before serving — what chefs call 'finishing salt'.

"Certain ingredients should be salted early on, while others should be salted later in the cooking process," Page said. "And some dishes should simply be finished with a sprinkling of salt before serving, allowing you to maximize both flavor and texture. Finishing salts are those whose flavor and texture are not enhanced via the cooking process and should be added at the very last minute to a dish."

Many cooks and chefs — including Page — keep a variety of salts on hand. Page and her co-author Dornenburg always have smoked salt in their pantry. "It's great to have both a sea salt and kosher salt on hand, plus a variety of finishing salts for different effects," she said.

"Smoked salt is great as a finishing touch to Andrew's vegetarian split pea soup. Some vegetarian friends have turned it away, thinking there was ham in it! But it's just the salt adding its smoky savoriness to the soup." Now that's one powerful garnish!