Salt is the most important ingredient in cooking. Without it, most meals would taste bland and unexciting. Salt is a crystalline mineral made of two elements, sodium (Na) and chlorine (Cl). Sodium and chlorine are absolutely essential for life in animals, including humans. They serve important functions like helping the brain and nerves send electrical impulses. The main difference between the salts is the taste, flavor, color, texture and convenience.
Refined Salt (table salt) is the most common. It is usually highly refined. It is heavily ground and most of the impurities and trace minerals are removed. The problem with heavily ground salt is that it can clump together. For this reason, various substances called anti-caking agents are added so that it flows freely. Food-grade table salt is almost pure sodium chloride, at 97% or higher. Iodine is often added to table salt.
Kosher Salt is used for all cooking. It dissolves fast, and its flavor disperses quickly, so chefs recommend tossing it on everything from pork roast to popcorn. Kosher salt got its name because its craggy crystals make it perfect for curing meat, a step in the koshering process. Cooks prize crystals like these, because their roughness makes it easy to pinch a perfect amount.
Himalayan Pink Salt is harvested in Pakistan. It is mined from the Khewra Salt Mine, the second largest salt mine in the world. Himalayan salt often contains trace amounts of iron oxide (rust), which gives it a pink color. It also contains small amounts of calcium, iron, potassium and magnesium, and slightly lower amounts of sodium than table salt.
Black Salt, also known as Kala Namak, is actually a pinkish-grey color. It is mined in India and has a strong sulphuric smell. It is commonly used to spice food in Southeast Asia and has recently become more popular in the US among vegan chefs who use it for the flavor.
Flaked Sea Salt adds a complex flavor to steamed vegetables or shellfish. This salt adds a hint of briny flavor. It comes from England's Essex coast. Its texture is soft, with sheer, pyramid-like flakes. This is the fastest-dissolving of all of the salt grains.
Celtic Salt is a type of salt that originally became popular in France. It has a greyish color and also comes from and contains a bit of water, which makes it quite moist. Celtic salt contains trace amounts of minerals and is a bit lower in sodium than table salt.
Rock Salt is used for making ice cream and de-icing. Rock salt is paired with ice in old-fashioned hand-cranked ice cream makers to regulate the temperature. It is also used to de-ice sidewalks and driveways during the winter. It is not sold for use directly on food. It is usually packaged in an organic, unprocessed form. It has large, chunky, non-uniform crystals. Minerals and other harmless impurities can give it a grayish color.
Crystalline Sea Salt is used for adding a pungent burst of flavor to just-cooked foods. These crystals can complement anything from a fresh salad to a salmon fillet. It comes from coasts from Portugal to Maine, California to the Pacific Rim. It can be either fine or coarse. The size of the irregular crystals affects how fast it dissolves. It varies in color, depending on the minerals it contains. These natural impurities can add subtle briny, sweet, or bitter flavors to the salts.
Fleur de Sel is a special-occasion table salt. It is delicately flavored and adds a perfect hint of saltiness to freshly sliced tomato or melon. It comes from coastal salt ponds in France. Some call it the caviar of sea salt and it is hand harvested. It is crystalline and melts slowly in the mouth.
Pickling Salt is used for brining pickles and sauerkraut. It is also used to brine a turkey, and is more concentrated than kosher salt. Pickling salt may come from the earth or the sea. It is almost one hundred percent sodium chloride and is the purest of salts.
Bottom line, the main purpose for salt is to add flavor, not nutrition.