Salt: Our 101

March 20, 2008

One of our readers, Bob Kilpatrick, sent me an email asking about the differences between salts. He noted that "these days it seems that there are more varieties of salts popping up on the store shelves; but truthfully isn't salt ... salt?"

What might be surprising to learn is that salt is sold in many different sizes and forms, depending on its intended use. Although sodium chloride is the main component of all salt, the texture and shape of the crystals also impacts taste and how the salt reacts with food. The three main varieties of salt are table salt, kosher salt and sea salt.

Coming from the earth or the sea, fine table salt usually contains additives to keep the small crystals from clumping due to moisture, which is more common in salts with smaller crystals. One such additive, iodine, has been added to table salt for years to help prevent iodine deficiency disorders (IDD). In the U.S., this process has effectively eliminated IDD, but around the world IDD continues to be a problem. Salt contains little iodine naturally, so fortifying it with added iodine can be an effective dietary solution, and the technology for doing so is readily available and inexpensive.

Kosher salt crystals are larger and coarser, and contain no additives. Many chefs prefer to cook with kosher salt, thanks to its crunchier texture and seasoning capabilities. This salt 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, like the name implies, is produced through the evaporation of seawater, and is usually less dense than table salt, and 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 salt is produced by one of three methods. The first and oldest method is called solar evaporation, and has been used since salt crystals were first noticed trapped in pools of sea water. 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 called 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 called vacuum evaporation, or the evaporation of salt brine by steam heat 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/day of sodium to maintain good health. Most Americans, however, consume much more than that – on average, about 3,500 mg/day. A minority of the population can lower blood pressure by restricting dietary salt, but there is no conclusive evidence that reducing dietary sodium improves the risks for heart attacks or strokes in the general population.

In fact, two recent studies provided conflicting results. In April 2007, the British Medical Journal looked at two prior clinical trials and found a 25% lower risk of cardiovascular events in a group that had reduced their sodium intake years earlier. Meanwhile, an October 2007 analysis of a large Dutch database, published in the European Journal of Epidemiology, documented no benefit of low-salt diets in reducing death rates, stroke or heart attack. So, it seems, the verdict is still out.

What we do know is that the body's salt to water ratio is vital to sustaining a healthy metabolism. Human blood contains .9% salt, which helps us maintain the electrolyte balance we need in and out of cells. Inadequate salt can lead to dehydration, especially in athletes.

China surpassed the U.S. as the world's top salt producer in 2006, producing 48 million metric tons. The U.S. came in second, with 46 million metric tons. Germany, India and Canada produced 18, 16, and 15 million metric tons, respectively. Worldwide production equaled a whopping 240 million metric tons. Throughout history, salt – or sodium chloride – has played an important role as one of the world's most effective food preservatives. Salt was used well before recorded history, played a vital part in the European exploration of the Americas, and has served a key role in many wars, economies and religions – as well as in diet and folklore.

Posted on Monday 3/24 by Dana
I've recently written a blog entry about salt that I think adds some info to this discussion ( you can read it here: http://danamccauley.wordpress.com/2008/03/19/fancy-and-flavoured-salt-101/).

What is important to remember is that many of the specialty salts currently becoming popular are meant to be used sparingly as finishing salts to add flavor but also texture to cooked foods.

Posted on Sunday 3/23 by Andrew
While there may not yet be a statistically proven direct link between excessive salt consumption and cardiovascular death, too much salt does cause or worsen a variety of potentially life-threatening conditions which, when salt consumption is drastically reduced, improve or stabilizein many sufferers. If your ankles swell up after a couple of trips through the drive-through, try cutting your salt, and, of course, see your doctor.

The real problem is that prepared food manufacturers think it's okay to load every serving with hundreds of milligrams of sodium. A typical can of soup, for example, contains as much as 900 mg. per "serving," or 1,800 mg. per can (what most people would normally consider a serving). A slice of pizza can have as much or more, and one Big Mac has a whopping 1,100 mg., which, with an order of fries, puts you dangerously close to the 1,500 mgt. daily limit that doctors recommend for most people, and especially those with hypertension or other water-retention problems.

Health and consumer advocates are pressuring the FDA to rein in the out-of-control food industry, and have even suggested that the FDA remove salt's GRAS (Generally Regarded as Safe) designation. Several European countries are ahead of us on this, and many American made food products have a lower salt content when sold in these countries.

But the solution lies within ourselves. We have to read labels, know what limits are best for us, and make the necessary sacrifices and substitutions in order to live a long and healthy life. The food industry is only giving us what they think we want. As Pogo said, "We have met the enemy, and he is us."

This discussion has been closed!