Salt is more than a flavor jump-start. It is one of the four basic flavors and an essen­tial nutrient that our bodies rightfully crave. Often incorrectly referred to as sodium, salt consists of 40 percent sodium and 60 per­cent chloride. While all salts originate from the sea, a number of the major North Amer­ican salt mines are nowhere near a presently existing ocean. Salt is concen­trated in underground deposits in unex­pected places such as Kansas, Ohio, and Michigan, which were at one point covered by the ocean. 

As a general rule, use coarse salt crys­tals in cooking water or to sprinkle onto or into foods for seasoning. Fine-grained salts are preferred for most baking because they measure and dissolve evenly. Here's a guide to common forms of salt available today. 

Table Salt: One of the most widely used salts, table salt goes through a refining process that removes traces of other natu­rally occurring minerals. Chemical additives such as sodium silicoaluminate, calcium phosphate, or magnesium carbonate are sometimes blended in to prevent clumping. Table salt and iodized salt are preferred in baking for their fine-grained texture and ac­curacy of measure. 

Iodized Salt: A form of table salt, iodized salt is fortified with iodine that was lost during processing. Iodized salt was the first "func­tional food," fortified in the early 1920s in re­sponse to a Midwest-focused epidemic of goiter (hyperthyroidism) that was caused by iodine deficiencies. 

Kosher Salt: This inexpensive salt is evaporated from a brine, usually under specific conditions approved by the Or­thodox Jewish faith. It contains no additives or added iodine. Kosher salt is popular among chefs because its coarse texture makes it easy to pinch up between your fin­gers and sprinkle onto foods. Measure for measure, 1 teaspoon of kosher salt contains less salt than the same amount, of table or iodized salt. 

Sea Salt: Available in 'both fine and coarse grains, sea salt has become in­creasingly available in markets but at a higher cost than table or kosher salt. Sea salt is made from evaporated sea water. Some salt farmers evaporate the water in enclosed bays along the shoreline, then rake up the salt by hand. This type of salt tends to include several naturally present trace minerals, such as iodine, magnesium, and potassium, which give sea salt a fresher, lighter flavor than standard table salt. Expensive varieties, such as sel gris, Esprit du Se/, and Fleur de Se/ from France are usually gray in color and slightly moist. These are best used where their tremendous flavor and presence is pronounced, such as on a boiled potato or a slice of tomato. You can also get pink, brown, and black sea salts from India. 

Rock Salt: Sold in large crystals, rock salt has a grayish hue because it is unre­fined. Rock salt makes a great bed for serving oysters and clams. Or combine it with ice to make ice cream in hand-cranked ice cream makers.