Salt Basics

July 02, 2012

What's the difference between all of the salts in the store, and how do they actually produce salt? Find out here

Salt is sold in many different sizes and forms, depending on its intended use. Sodium chloride is the main component of all salt, but the texture and shape of the crystals also impacts taste and cooking. The three main varieties of salt are table salt, kosher salt and sea salt.

Salts are derived from either the earth or the sea. Fine table salt (aka salt) usually contains additives to keep it from clumping due to moisture. Another additive, iodine, has been added to table salt for years to help prevent iodine deficiency disorders (IDD). In the United States, this process has effectively eliminated IDD, but around the world, IDD continues to be a problem.

Kosher salt crystals are larger, coarser, and do not contain additives. Many chefs prefer to cook with kosher salt, because of its heartier texture and seasoning capabilities. It is also used to kosher meat. Harvested like table salt, kosher salt is raked during evaporation, giving the grains a block-like structure.

Sea salt, as the name implies, is produced through the evaporation of seawater, and is usually less dense than table salt, therefore less salty. Sea salt can come in different colors and adds either a briny, sweet, or bitter taste to food, depending on the type of natural impurities it contains.

Other varieties of salt include fleur de sel, a slow-melting, hand-harvested crystalline salt that provides an earthy, pleasing flavor; chunky rock salt, which is used for making ice cream and de-icing roads; and fine-grained, concentrated pickling salt, which is used for brining pickles and sauerkraut.

Most salts are produced by one of three methods. The first and oldest method is solar evaporation, and has been used since salt crystals were first noticed trapped in pools of seawater. Solar salt production is the process of capturing salt water in shallow ponds and then allowing the sun to evaporate most of the water. Mechanical harvesting machines then gather the concentrated brine, and remove impurities. The result is pure salt crystallization.

A second common method is rock salt mining, one of the most dramatic methods of gathering salt. Mined salt appears in veins or domes, which are formed as pressure from the Earth forces salt up through cracks in bedrock. Salt is mined by a room and pillar method in a checkerboard pattern - leaving some salt pillars up for roof support. Once above ground, rock salts are separated by size and shipped to customers.

The third method is vacuum evaporation, or the evaporation by steam in large commercial evaporators. This method results in high purity salt that is fine in texture and is accomplished through the drilling of wells in salt deposits. Water is pumped into the well, dissolving the salt, and pushing the resulting brine up to the surface. Brine is then transferred to a processing area and boiled until all water is evaporated.

The National Academy of Sciences recommends that Americans consume a minimum of 500 mg per day of sodium to maintain good health. Most Americans consume much more than that -- on average, about 3,500 milligrams a day! To find our where salt may be hiding in your diet click here.