Salt - information every cook should know

By JOE O'CONNELL, cbbqa Past President
First posted August 24, 2001

Updated By BILL WIGHT, cbbqa member
December 10, 2002

Salt has been used since antiquity to preserve and season food.  But cooks routinely make mistakes in using salt.  This will explain the necessary information..

Non-biological food

Salt is a mineral and the only non-biological food that humans eat routinely.  Interestingly, water is the only non-biological liquid that humans drink routinely.

Chemistry

Common salt or table salt, is a compound called sodium chloride.  That is, salt is a molecule that combines one atom of sodium (Na) and one atom of chlorine (Cl), which forms a molecule of sodium chloride (NaCl).  To make sodium chloride in the laboratory, you can react caustic soda (NaOH) with hydrochloric acid (HCl), to produce NaCl and water (H₂O).  

In fact, the combination of any acid and base forms a salt plus water, which is written in the chemical equation:

acid + base -> salt + water

Examples of such salts include potassium chloride, silver nitrate and barium sulfate.  See Laszlo at 141.  For more information about salt's crystalline form, its cubic structure, its chemical properties, and similar facts, see the Salt Institute.

Where salt comes from

Commercial salt is produced in three ways.

Sea salt (or "solar salt") refers to salt which is produced by evaporating sea water ("salt water") in large ponds.  Sea water contains about 2.6% sodium chloride (by weight), and there is an inexhaustible supply.  Sea salt is generally more expensive than mineral salt.  It is usually sold as a coarse salt (and alternative to Kosher salt) and contains other trace elements which give sea salt a unique flavor.

Mineral salt occurs naturally in many places in the world as the mineral halite ("rock salt").  It is mined and used in many processes.  Most commercial table salt is mined.

Chemical processes can be used to produce a highly pure form of salt, but this is very expensive and restricted primarily for health and scientific purposes. 

Why salt works:  taste and smell

Salt is one of only four tastes that the human tongue can distinguish.  (The others are "bitter", "sweet" and "sour".)

This article uses the following terms:  the word "taste" refers only to the perceptions of the tongue;  the word "smell" refers only to the perceptions of the nose;  and the word "flavor" refers to the perceptions of both the tongue and nose (so flavor combines taste and smell).  

When the tongue tastes the salt, the brain receives a message that something is being eaten, so the brain tells the nose to start to work.  When the nose receives the message, the nose begins to sense smells of the food.  A person perceives that the salt "enhances" that flavor of the food, but in reality the salt only wakes up the odor receptors.

As a result, the nose will be turned on as soon as the tongue taste salt.  It follows that the salt can be added either in the food or in any accompanying manner.  Having a saltine just before eating a bowl of carrots will have the same effect as salting the carrots before eating.

Why Kosher salts works better in brines

There are many myths and urban legend nonsense about why barbecue cooks should use Kosher salt for brining.  Here is the science (and fact).

The structure of mineral salt is as a cubic crystal.  A single grain of Kosher salt is composed of many cubes, stuck together into a big grain.  As a result, a single grain of Kosher salt can absorb much more liquid than a grain of granulated salt.  (To the right is a photograph of a grain of Kosher salt, magnified 75 times.)

Equivalents

A grain of Kosher salt is larger than that of a grain of table salt.  As a result, a teaspoon of Kosher salt does not weigh as much as a teaspoon of table salt.  Most recipes that require the addition of salt assume that the salt is fine-grained table salt.  Therefore, if a recipe requires a certain amount of table salt, the question is "how much Kosher salt is needed to equal a certain amount of table salt?"

Unfortunately, not all Kosher Salts are the same.  They have salt grains which are of different sizes, so their table-salt equivalents are different.

Morton's Coarse Kosher Salt is simply granulated (table) salt that has been compacted into flat flakes.  Morton's Coarse Kosher Salt weighs 8.1 oz. per cup, while ordinary table salt weighs 10.2 oz. per cup.  Therefore, one part of table salt can be replaced with 1 1/4 part of Morton's Coarse Kosher Salt.  For example, a recipe that requires 4 teaspoons of table salt would require 5 teaspoons of Morton's Kosher Salt.  Alternatively, because they are almost equivalent, Morton's itself recommends that its Kosher Salt may be used measure for measure in place of table salt in quantities under a cup.

Here is the entire email received from Morton Salt on October 31, 2001 at 12:29 PM PST (2029 GMT):

Thank you for contacting Morton Salt.

The brand of Kosher salt that is used will affect the amount of Kosher salt that should be used when "Salt" is called for in a recipe.  For Morton Coarse Kosher salt, the salt particles are larger than granulated table salt so there will be some differences.  Generally, Coarse Kosher Salt and Table Salt can be interchanged in cooking when small amounts of salt are used.  One cup of Table salt is 10.2 oz, while Morton Coarse Kosher Salt is 8.1 oz. per cup.  In this case, 1-1/4 cups Coarse Kosher Salt should be used for 1 cup of Table Salt.

We hope this information is useful to you.

Sincerely,

MORTON SALT
Consumer Affairs web site

On the other hand, Diamond Crystal Kosher Salt weighs 5 oz. per cup.  Therefore, a recipe which requires one part of table salt may substitute 2 parts of Diamond Crystal Kosher Salt.  

Sea salt and other brands of Kosher Salt should also usually be used in a two-for-one ratio.  

However, in the case of a recipe in which the amount of salt is important, the weight of the salt should be compared with table salt.

Finally, salt is salt when it is in a liquid.  That is, there is absolutely no chemical difference (except as noted below for the impurities and additives) between Kosher Salt, sea salt, table salt and the other salts listed below, when they are dissolved in water.  The exception is related to additives, either natural or processed.  Sea salt, for example, contains "impurities" which give it a special taste and color, and many commercial salts (like Morton's Iodized Table Salt) contain additives for various purposes (these are described in detail below).

Kosher, sea, table and other salts

Salt comes in many varieties:  table salt, sea salt, Kosher salt, canning salt, pickling salt, and even "lite" salt.  The most important of these will be discussed.

Kosher salt is a coarse flake salt.  It usually contains calcium silicate  (in the United States) or another anti-caking agent (in other countries) to prevent caking, but its grains are very large and coarse.  Kosher salt contains no iodine. In certain recipes (and in Margaritas), Kosher salt adds a "crunchy" texture. 

Sea salt is a coarse, flake salt, like Kosher salt.  Unlike Kosher salt, however, sea salt contains many "impurities" -- trace amounts of minerals from evaporated sea water -- which add a slightly different taste.  Some sea salts (like "Black Sea Salt") have distinct flavors because of the presence of trace elements and minerals.

Rock salt is sold in large chunky crystals but is not usually sold as "food grade".  Rock salt is used to make ice cream and for similar cooling purposes.   

Most commercial salts other than Kosher Salt are fine-grain.

Table salt means a fine-grain ("granulated") salt to which is added an agent to keep it from lumping.  Table salt can be purchased with iodine ("iodized") or without ("plain"), but it contains calcium silicate to prevent caking (see additives, below).

Canning and pickling salt means a fine-grain salt with no additives (neither iodized nor anti-caking agents).  This is better for certain recipes, in which calcium silicate may cloud the liquid or settle to the bottom.  

Popcorn salt has grains even finer (smaller) than table salt, which means that it will stick better to popcorn.

In summary, granulated (fine grain) salt comes in three varieties:  with no additives whatsoever ("Canning and pickling salt");  with only anti-caking agents added ("Plain Table Salt");  and with both anti-caking and iodine added ("Iodized Table Salt").

Some commercial "salt" contains less or no "sodium".

Lite salt uses the salt potassium chloride in equal parts with sodium chloride (regular salt).  This reduced the amount of sodium in the salt.

Salt substitutes have no sodium and use only potassium chloride, for people on a sodium-restricted diet.

More information about commercial salts is available at Morton Salt's website and in the Epicurious Online Food Dictionary.

Gourmet Salt

In Guérande France, Only Women Are Allowed To  Do It

If you ever thought that salt was just plain old salt, you should visit Guérande. On France's Atlantic coast, on the edge of a sweeping, shallow bay, stretch marshes where salt production has been raised to an art form. As with all classical art forms, the raw materials are relatively simple: seawater, sun, and wind.

Drawing: A harvester creates gentle waves that push salt crystals into a pile, where they will dry. MEG MATSON

The sun and wind evaporate the seawater, and you are left with salt. But not just any common table salt. One of two salts produced here is "The Flower of Guérande," whose crystals are skimmed almost individually from the surface of the shallow water in salt pans - only in the evenings, only after the hottest days, only when the breeze is right, and only by women.

The salt smells faintly of violets. Lest you think this is a marketing gimmick, a cunning way to get daft "foodies" to pay $20 a pound for salt instead of less than 50 cents, which ordinary table salt costs, hear what Jean-Marc Notelet, a Paris chef, has to say of sel [salt] de Guérande. "I don't use a grain of refined salt in my kitchen," he explains. "It burns the food it touches the way it burns your tongue if you taste it. But Guérande salt is more subtle, less salty, less aggressive. It is just more agreeable."

Pricey 'fleur de sel' is worth its salt -- and then some

By Maria Puente / USA TODAY

Americans have learned to be choosier eaters, and we're getting more so, even about our condiments. You've heard of "gourmet" olive oil, vinegar, honey. Now there's gourmet salt.

For some discerning palates, the regular stuff isn't good enough anymore. Now top chefs and health-conscious diners reach for "natural" sea salt -- or even better, "fleur de sel" (flower of salt), the creme de la creme of sea salts, which can cost $56 a pound.

"It has a distinct and delicate flavor, and mineral characteristics that accentuate raw seafood or vegetables, a quality of earthiness that heightens everything on a plate," rhapsodizes Matthias Merges, chef de cuisine at Charlie Trotter's restaurant in Chicago.

But sea salt is still salt. It's imported, harvested from seawater by salt "farmers" using medieval techniques. The moist, coarse, grayish-white, crumbly crystals contain about 85 percent sodium chloride, plus magnesium, calcium and other beneficial minerals. Fleur de sel is used for "finishing" only; regular sea salt is used for cooking. (Kosher salt has a similar texture, but it's only regular salt processed under Jewish dietary laws.)

Regular iodized table salt, dug out of domestic mines formed by seawater millions of years ago, is about 99 percent sodium chloride with traces of minerals. Cheap and plentiful, it's about 50 cents a pound.

As with wine and olive oil, sea salt prices and flavors depend on who makes it and where. The sea salt best known in the United States comes from France: Farmers channel seawater into clay ponds where it evaporates and eventually turns to salt crystals. Fleur de sel is the best, harvested by hand-skimming the ponds' surfaces.

Why go to such trouble? Fans say this salt not only tastes better, it's also better for you because it contains none of the additives typically used in regular salt, such as anti-caking chemicals.

"People are paying more attention to their health and seeking out more natural, unprocessed foods," says Marquita Moore, general manager of the Grain and Salt Society. The Asheville, N.C., company is one of the largest importers of fleur de sel, which it sells as Flower of the Ocean for $56 a pound. In 1980, the firm imported about 7,000 pounds of sea salt; now, 300,000 pounds a year.

Health food stores and high-end groceries carry a plethora of choices: Dean & Deluca stocks brands from England, Italy and France, at prices from $2.25 for about 8 ounces to $9.75 for 4.4 ounces.

There's even a restaurant called Fleur de Sel, opened recently in New York. Chef-owner Cyril Renaud's French relatives get a special fleur de sel made by small producers on the island of Noirmoutier. Served in small containers on the restaurant's tables, it "lights up the food, makes it lively," Renaud says.

But taste is subjective: Recently, Good Housekeeping magazine reports that in blind tests, only two of eight tasters chose Flower of the Ocean over two kinds of domestic kosher salt.

Additives

Commercial salt often contains additives for dietary or aesthetic reasons.

Potassium iodide is added to table salt for health reasons.  A lack of iodine in the diet causes "goiter", a thyroid gland deficiency.  Iodine is added to table salt in the form of potassium iodide.

Dextrose is a sugar that stabilizes the iodine in commercial salt.  Morton's Iodized Table Salt contains 0.04 percent dextrose or 40 milligrams per 100 grams of salt, which is so small an amount that it is dietetically insignificant..  

Calcium silicate is a white, odorless, tasteless, anti-caking agent with no nutritional characteristics.  Anti-caking agents basically serve to absorb moisture inside the package that would otherwise be absorbed by the salt.  In this manner, it permits salt to keep its freeflowing characteristics.  It is added at less than one half-percent to both iodized and plain table salt.  However, calcium silicate is not water soluble, so it may cloud that water and settle at the bottom of some canning recipes (which is an aesthetic issue but not a health problem).  

There is more information on this at Morton's website. 

Further information

• Myths and urban legends about salt
• Morton Salt
• Flower of Guerande
• Salt Institute about salt
• Chemistry - Salt Institute salt chemistry
• Salt Institute on salt in food
• Salt Institute resource guide
• Chemistry of salt
• Navy on structure of sodium chloride
• Image of a single grain of Kosher salt
• Cooks Thesaurus on Salt
• Mrbloch salt archive
• WaltonFeed.com overview of terms and types of salt
• Redmond Real Salt sea salt
• WaltonFeed.com introduction to salt
• Laszlo, Pierre.  Salt.  Columbia University Press, New York, 1998 (trans by Mary Beth Mader).