General & History
8000 years ago in Rumania, large scale salt production was already under way. Brine from a salt spring was concentrated into crystal salt by boiling it dry in clay pots. The pots were broken and the salt packaged for a very profitable trade with peoples in regions without a good supply. In China, salt harvesting from a salt lake began around the same time.
A major use of salt from those times was to preserve meat, fish, and later vegetables. While this is no longer necessary in developed regions of the world, the unique flavors produced by salt preservation have kept salted fish, meat and vegetables in high demand.
While the often repeated story that Roman legions were paid in salt is not actually true, it was still a very expensive commodity. Celts in Austria made a good living selling salted meat to Greece and Rome up to the beginning of the Common Era. By the Renaissance transportation and production had improved to the point salt was well on it's way to being the low cost commodity it is today.
Today food grade salt is a rather small market, accounting for less than 5% of production in Europe and North America. The rest goes to Industrial applications. World production is over 240 million tons per year.Varieties of Salt
There are two basic varieties of food grade salt: Refined Table Salt and Natural Salt, which may be evaporated from seawater or mined from deposits left by vanished lakes, seas and salt flats.
To make it shake even better small amounts of anti-caking substances are
added. A number of these are in use: tricalcium phosphate, calcium or
magnesium carbonates, fatty acid salts (acid salts), magnesium oxide,
silicon dioxide, calcium silicate, sodium aluminosilicate, calcium
aluminosilicate and Sodium ferrocyanide (yellow prussiate of soda).
Iodized Salt: This is usually Table Salt, but Sea Salt and Mineral Salt are also often iodized by addition of small amounts of Iodine compounds. Dietary iodine is insufficient for health in many inland and mountainous regions, causing swollen thyroid (goiter), stunted growth and severe mental retardation (cretinism). Iodized salt has largely eliminated these problems in North America, but the program is now loosing effectiveness due to various influences (see Salt and Health). Iodized salt also generally contains a very small (0.04%), nutritionally insignificant amount of the sugar dextrose, which stabilizes the potassium iodide to prevent free iodine in the salt.
Cook's Illustrated ran comparative tests in their test kitchen using salted popcorn. A few people said they could detect a faint chemical aftertaste from the iodized salt but most said they could detect no difference between iodized and non-iodized.
But you have sea salt without these problems? Ha! You've been deceived. Major salt processors refine sea salt to the point it isn't much different from their regular table salt, but since it came from seawater they call it "sea salt" and charge a higher price for it. Real sea salt is slightly bitter and would cake badly if ground fine due to moisture content. It's about 86% Sodium Chloride and the rest is moisture and other mineral salts (analysis in Salt & Health). Some purveryors of sea salt say it is "lower sodium" than regular salt, but you may have to use more for the same saltiness.
Celtic Sea Salt® is a brand name (established 1976) for very strongly marketed natural sea salts in the style of Brittany, France, but sourced from various regions. French Grey Sea Salt (Sel Gris) from Brittany is light grey in color from the clay salt pans it is harvested from. These are the same salt pans Sel de Fleur is harvested from.
An economical place to get natural sea salt is from a Korean market,
because natural sea salt is important to making salt fermented kimchi,
and without kimchi there is no Korean cuisine. The photo specimen is
Korean. Here in Los Angeles it sells for around 2015 US $1.50/pound in
2 pound bags, less in larger bags.
Natural mined salt is generally slightly gray in color, though it can
be other colors depending on what geological processes it's gone through
and what minerals were carried through it by groundwater. The photo
specimens are from Russia (left) and Armenia (right). They are ground
coarser than table salt and are slightly gray with a few darker speck
in them. They can be used in salt shakers if the shaker is sturdy enough
to be whacked firmly to break up the clumps every time you use it.
Celebrity chefs and writers of gourmet recipes now automatically call for kosher salt - its the "in" thing. They imagine the iodine in the salt will ruin the taste of their recipe, though it is highly unlikely to be at all detectable. This is worrisome to health officials, but celebrity chefs aren't concerned about your health, they are concerned about your wallet. If avoiding iodine is the point, non-iodized table salt is just as easily available today.
The one place where kosher salt has a definite advantage is in rubs and the like, where you don't want the crystals to dissolve quickly - and there the low density Diamond Crystal salt has a wide advantage over others. Twice the volume for the same saltiness makes for a more even coating.
It pisses me off that chefs and food writers automatically call for
"kosher salt" without specifying which brand they use. Different volume
for the same saltiness makes it necessary to adjust recipes. Multiply
by the adjustments below when converting table salt to kosher - divide
by the adjustment when converting kosher to table salt.
Ice Cream Salt
Himalayan Pink Salt
Numerous health claims are made for this salt, but none have been scientifically verified. Basically, it's Precambrian sea salt (somewhat different composition from current sea salt) contaminated by ground water with minerals (zinc, iron, sulphur, copper, chromium and others). It may have between 60 and 84 minerals, but since it's 98% Sodium Chloride, and most of the rest is Iron and Sulphur, there's likely little benefit from the trace minerals, at least for the quantities you should be using salt in. On the upside, there will be correspondingly little harm from the toxic minerals it contains (including uranium, radium, plutonium, lead and mercury). If you like it, use it, but don't expect much in health benefits.
The photo specimens were purchased from an Indian market in Glendale,
California, labeled simply "Natural Crystal Salt" - but they still
charged over US $4.50 per pound. Yes, it tastes pretty much like salt -
but at least you can be pretty sure it isn't refined. If you buy it
ground, you can't tell what it might be, and it is often faked up
Finishing Salts are salts that are sprinkled on food at the time of serving, though they may also be included in rubs and the like. They generally have an unusual texture, unusual color, or both, and may have slight differences in taste. You would not use them for cooking, because the texture and color and taste you are paying for would be totally lost. Various health claims are made, including that they have less sodium than regular table salt, but this is true of any natural sea salt. Few have a flavor much different from that of natural sea salt.