Welcome to the I Can't Sleep Podcast,
Where I help you drift off one fact at a time.
I'm your host,
Benjamin Boster,
And today's episode is about salt.
This sponsored episode is an early birthday present to Tara from Russell.
Salt is a mineral composed primarily of sodium chloride.
When used in food,
Especially in granulated form,
It is more formally called table salt.
In the form of a natural crystalline mineral,
Salt is also known as rock salt or halite.
Salt is essential for life in general,
Being the source of the essential dietary minerals sodium and chlorine.
And saltiness is one of the basic human tastes.
Salt is one of the oldest and most ubiquitous food seasonings and is known to uniformly improve the taste perception of food.
Salting,
Brining,
And pickling are ancient and important methods of food preservation.
Some of the earliest evidence of salt processing dates to around 6000 BC,
When people living in the area of present-day Romania boiled spring water to extract salts.
A salt works in China dates to approximately the same period.
Salt was prized by the ancient Hebrews,
Greeks,
Romans,
Byzantines,
Hittites,
Egyptians,
And Indians.
Salt became an important article of trade and was transported by boat across the Mediterranean Sea,
Along especially built salt roads,
And across the Sahara on camel caravans.
The scarcity and universal need for salt have led nations to go to war over it and use it to raise tax revenues.
For instance,
Triggering the El Paso Salt War,
Which took place in El Paso in the late 1860s.
Salt is used in religious ceremonies and has other cultural and traditional significance.
Salt is processed from salt mines and by the evaporation of seawater,
Sea salt,
And mineral-rich spring water in shallow pools.
The greatest single use for salt is a feedstock for the production of chemicals.
It is used to produce caustic soda and chlorine,
And in the manufacture of products such as polyvinyl chloride,
Plastics,
And paper bulbs.
Of the annual global production of around 300 million tons,
Only a small percentage is used for human consumption.
Other uses include water conditioning processes,
De-icing highways,
And agricultural use.
Edible salt is sold in forms such as sea salt and table salt.
Table salt usually contains an anti-caking agent and may be iodized to prevent iodine deficiency.
As well as its use in cooking and at the table,
Salt is present in many processed foods.
All through history,
The availability of salt has been pivotal to civilization.
What is now thought to have been the first city in Europe is Solnesada in Bulgaria,
Which was a salt mine,
Providing the area now known as the Balkans with salt since 5400 BC.
Salt was the best known food preservative,
Especially for meat,
For many thousands of years.
A very ancient salt works operation has been discovered at the Poiana Slătani archaeological site,
Next to a salt spring in Lunca-Niapce County,
Romania.
Evidence indicates that Neolithic people of the Pre-Cucuteni culture were boiling the salt-laden spring water through the process of brigatons to extract salt as far back as 6050 BC.
The salt extracted from this operation may have directly correlated with the rapid growth of the society's population soon after production began.
The harvest of salt from the surface of Xiechi Lake near Yuncheng in Shanxi,
China,
Dates back to at least 6000 BC,
Making it one of the oldest verifiable salt works.
With the spread of civilization,
Salt became one of the world's main trading commodities.
It was a high value to the ancient Hebrews,
The Greeks,
The Romans,
The Byzantines,
The Hittites,
And other people of antiquity.
In the Middle East,
Salt was used to seal an agreement ceremonially,
And the ancient Hebrews made a covenant of salt with God and sprinkled salt on their offerings to show their trust in Him.
Salt may have been used for barter in connection with the obsidian trade in Anatolia in the Neolithic era.
Salt was included among funeral offerings found in ancient Egyptian tombs from the 3rd millennium BC,
As were salted birds and saltfish.
From about 2800 BC,
The Egyptians began exporting saltfish to the Phoenicians in return for Lebanon's cedar,
Glass,
And the dye tyran purple.
The Phoenicians traded Egyptian salted fish and salt from North Africa throughout their Mediterranean trade empire.
Herodotus described salt trading routes across Libya back in the 5th century BC.
In the early years of the Roman Empire,
Roads were built for the transportation of salt from the salt imported at Ostia to the capital.
In Africa,
Salt was used as currency south of the Sahara.
Slibes of rock salt were used as coins in Abyssinia.
The Tuareg have traditionally maintained routes across the Sahara,
Especially for the transportation of salt by Azalee salt caravans.
The caravans still cross the desert from the southern Niger to Bilma,
Although much of the trade now takes place by truck.
Each camel takes two blades of fodder and two of trade goods northwards and returns laden with salt pillars and dates.
In Gabon before the arrival of Europeans,
The coast people carried on a remunerative trade with those of the interior by the medium of sea salt.
This was gradually displaced by the salt the Europeans brought and sacks.
So the coast natives lost their previous profits.
As of the late 1950s,
Sea salt was still the currency best appreciated in the interior.
Salzburg,
Hallstatt,
Hallein lie within 17 kilometers of each other on the river Salzach in central Austria,
In an area with extensive salt deposits.
Salzach means Salt River,
While Salzburg means Salt Castle,
Both taking their names from the German word Salz,
Salt.
Hallstatt was the site of the world's first salt mine.
The town gave its name to the Hallstatt culture that began mining for salt in the area in about 800 BC.
Around 400 BC,
The townsfolk,
Who had previously used pickaxes and shovels,
Began open pan salt making.
During the first millennium BCE,
Celtic communities grew rich trading salt and salted meat to ancient Greece and ancient Rome in exchange for wine and other luxuries.
The word salary comes from the Latin word for salt.
The reason for this is unknown.
A persistent modern claim that the Roman legions were sometimes paid in salt is baseless.
The word salad literally means salted and comes from the ancient Roman practice of salting leaf vegetables.
Wars have been fought over salt.
Venice won the Salt War 1304 with Padua over supplying the product in certain areas.
And the War of Ferrara,
1482-1484 for the same reason.
It played a role in the American Revolution and the San Elisario Salt War.
Cities on overland trade routes grew rich by levying duties,
And towns like Liverpool flourished on the export of salt extracted from the salt mines of Chichester.
Governments have at different times imposed salt taxes on their peoples.
The voyages of Christopher Columbus are said to have been financed from salt production in southern Spain.
The oppressive salt tax in France was one of the causes of the French Revolution.
After being repealed,
This tax was re-imposed by Napoleon when he became the emperor to pay for his foreign wars and was not abolished until 1946.
In 1930,
Mahatma Gandhi led a crowd of 100,
000 protesters on the Dandi March,
Or Salt Satyagraha,
During which they made their own salt from the sea,
As a demonstration of their opposition to the colonial salt tax.
This act of civil disobedience inspired numerous individuals and transformed the Indian independence movement into a national struggle.
Salt is essential to the health of humans and other animals,
And it is one of the five basic taste sensations.
It is known to uniformly improve the taste perception of food,
Including otherwise unpalatable food.
Salt is used in many cuisines,
And it is often found in salt shakers on diners' eating tables for their personal use on food.
Salt is also an ingredient in many manufactured foodstuffs.
Table salt is a refined salt containing about 97-99% sodium chloride.
Usually anti-cacane agents such as sodium aluminosolicate or magnesium carbonate are added to make it free-flowing.
Iodized salt containing potassium iodide is widely available.
Some people put a desiccant,
Such as a few grains of uncooked rice or a salting cracker in their salt shakers,
To absorb extra moisture and help break up salt clumps that may otherwise form.
A lack of fluoride in the diet is a cause of a greatly increased incidence of dental caries.
Fluoride salts can be added to table salt with the goal of reducing tooth decay,
Especially in countries that have not benefited from fluoridated toothpaste and fluoridated water.
The practice is more common in some European countries where water fluoridation is not carried out.
In France,
35% of the table salt sold contains added sodium fluoride.
Unrefined sea salt contains small amounts of magnesium and calcium halides and sulfates,
Traces of algal products,
Salt-resistant bacteria,
And sediment particles.
The calcium and magnesium salts confer a faintly bitter overtone,
And they make unrefined sea salt hygroscopic,
I.
E.
,
It gradually absorbs moisture from air if stored uncovered.
Algal products contribute a mild fishy or sea air odor,
The latter from organobromine compounds.
Sediments,
The proportion of which varies with the source,
Give the salt a dull grey appearance.
Since taste and aroma compounds are often detectable by humans in minute concentrations,
Sea salt may have a more complex flavor than pure sodium chloride when sprinkled on top of food.
When salt is added during cooking,
However,
These flavors would likely be overwhelmed by those of the food ingredients.
The refined salt industry cites scientific studies saying that raw sea and rock salts do not contain enough iodine salts to prevent iodine deficiency diseases.
Salts have diverse mineralities,
Depending on their source,
Giving each a unique flavor.
Fleur de sel,
A natural sea salt from the surface of evaporating brine and salt pans,
Has a distinctive flavor varying with its source.
In traditional Korean cuisine,
So-called bamboo salt is prepared by roasting salt in a bamboo container plugged with mud at both ends.
This product absorbs minerals from the bamboo and the mud,
And has been claimed to increase the anti-clostagenic and anti-mutagenic properties of dunzheng,
A fermented bean paste.
Kosher for kitchen salt has a larger grain size than table salt and is used in cooking.
It can be used for brining,
In bread or pretzel making,
And as a scrubbing agent when combined with oil.
Salt is present in most foods,
But in naturally occurring foodstuffs,
Such as meads,
Vegetables,
And fruit,
It is present in very small quantities.
It is often added to processed food,
Such as canned foods and especially salted foods,
Pickled foods and snack foods,
Or other convenience foods,
Where it functions as both a preservative and a flavoring.
Dairy salt is used in the preparation of butter and cheese products.
As a flavoring,
Salt enhances the taste of other foods by suppressing the bitterness of those foods,
Making them more palatable and relatively sweeter.
Before the advent of electrically powered refrigeration,
Salting was one of the main methods of food preservation.
Thus,
Herring contains 67 mg sodium per 100 g,
While kipper,
Its preserved form,
Contains 990 mg.
Similarly,
Pork typically contains 63 mg,
While bacon contains 1,
480 mg.
And potatoes contain 7 mg,
But potato crisps 800 mg per 100 g.
Salt is used extensively in cooking as a flavoring,
And in cooking techniques such as with salt crusts and brining.
The main source of salt in the Western diet,
Apart from direct use,
Are bread and cereals,
Meat and dairy products.
In many East Asian cultures,
Salt is not traditionally used as a condiment.
In its place,
Condiments such as soy sauce,
Fish sauce,
And oyster sauce tend to have a high sodium content and fill a similar role to table salt in Western cultures.
They are most often used for cooking rather than as table condiments.
Only a small percentage of the salt manufactured in the world is used in food.
The remainder is used in agriculture,
Water treatment,
Chemical production,
De-icing,
And other industrial use cases.
In the practice of watering plants with salt as a fertilizer,
Applying a moderate concentration helps avoid potential toxicity.
Typically,
One to three grams per liter is considered safe and effective for most plants.
Sodium chloride is one of the most widely used inorganic raw materials.
It is a feedstock in the production of caustic soda and chlorine.
These are used in the manufacture of PVC,
Paper pulp,
And many other inorganic and organic compounds.
Salt is used as a flux in the production of aluminum.
For this purpose,
A layer of melted salt floats on top of the molten metal and removes iron and other metal contaminants.
It is used in the manufacture of soaps and glycerin,
Or it is used to saponify fats.
As an emulsifier,
Salt is used in the manufacture of synthetic rubber,
And another use is in the firing of pottery,
When salt added to the furnace vaporizes before condensing onto the surface of the ceramic material,
Forming a strong glaze.
When drilling through loose materials such as sand or gravel,
Salt may be added to the drilling fluid to provide a stable wall to prevent the hole collapsing.
There are many other processes in which salt is involved.
These include its use as a mordant in textile dyeing,
To regenerate resins in water softening,
For the tanning of hides,
The preservation of meat and fish,
And the canning of meat and vegetables.
Food grade salt accounts for only a small part of salt production in industrialized countries,
7% in Europe,
Although the worldwide food uses account for 17.
5% of total production.
In 2018,
Total world production of salt was 300 million tons.
The top six producers being China,
68 million,
The United States,
42 million,
India,
29 million,
Germany,
13 million,
Canada,
13 million,
And Australia,
12 million.
The manufacture of salt is one of the oldest chemical industries.
A major source of salt is seawater,
Which has a salinity of approximately 3.
5%.
This means that there are about 35 grams of dissolved salts,
Predominantly sodium and chloride ions per kilogram of water.
The world's oceans are a virtually inexhaustible source of salt,
And this abundance of supply means that reserves have not been calculated.
The evaporation of seawater is a production method of choice in marine countries with high evaporation and low precipitation rates.
Salt evaporation ponds are filled from the ocean,
And salt crystals can be harvested as the water dries up.
Sometimes these ponds have vivid colors,
As some species of algae and other microorganisms thrive in conditions of high salinity.
Away from the sea,
Salt is extracted from the vast sedimentary deposits which have been laid down over the millennia from the evaporation of seas and lakes.
These sources are either mined directly,
Producing rock salt,
Or are extracted by pumping water into the deposit.
In either case,
The salt may be purified by mechanical evaporation of brine.
Traditionally,
Purification was achieved in shallow open pans that were heated to accelerate evaporation.
Vacuum-based methods are also employed.
The raw salt is refined by treatment with chemicals that precipitate most impurities,
Largely magnesium and calcium salts.
Multiple stages of evaporation are then applied.
Some salt is produced using the Albager process,
Which involves vacuum pan evaporation combined with the seeding of the solution with cubic crystals,
And produces a grainy type flake.
The Ayoreo,
An indigenous group from the Paraguayan Chaco,
Obtained their salt from the ash produced by burning the timber of the Indian salt tree and other trees.
The largest mine operated by underground workings in the world is the Sifto Mine,
Located mostly 550 meters below Lake Huron in Goderich,
Ontario,
Canada.
About 7 million tons of salt are extracted from it annually.
The Kura salt mine in Pakistan has 19 stories,
11 of which are underground,
And 400 kilometers of passages.
The salt is dug out by the room and pillar method,
Where about half the material is left in place to support the upper levels.
Extraction of the Himalayan salt is expected to last 350 years at the present rate of extraction of around 385,
000 tons per annum.
The mine is also a major tourist attraction,
Receiving around a quarter of a million visitors a year.
Salt has long held an important place in religion and culture.
At the time of Brahmanic sacrifices,
In Hittite rituals and during festivals held by Semites and Greeks at the time of the new moon,
Salt was thrown into a fire where it produced crackling noises.
The ancient Egyptians,
Greeks,
And Romans invoked their gods with offerings of salt and water,
And some people think this to be the origin of holy water in the Christian faith.
In Judaism,
It is recommended to have either a salty bread or to add salt to the bread if this bread is unsalted when doing Kiddush for Shabbat.
It is customary to spread some salt over the bread or dip it into a little salt when passing it around the table after the kadoosh.
To preserve the covenant between their people and God,
Jews dip the Sabbath bread in salt.
Salt plays a role within different Christian traditions.
It is mandatory in the rite of the Tridentine Mass.
Salt is used in the third item of the Celtic consecration that is employed in the consecration of a church,
And it is permitted to be added to the water where it is customary in the Roman Catholic rite of holy water.
The Bible makes multiple mentions of salt,
Both of the mineral itself and as a metaphor.
Uses include the tale of how Lot's wife is turned into a pillar of salt when looking back at the cities of Sodom and Gomorrah as they are destroyed.
In the New Testament,
Jesus refers to his followers as the salt of the earth.
In Aztec mythology,
Huitzilopochtli was a fertility goddess who presided over salt and salt water.
Salt is an auspicious substance in Hinduism and is used in ceremonies like house warmings and weddings.
In Jainism,
Devotees lay an offering of raw rice with a pinch of salt before a deity to signify their devotion,
And salt is sprinkled on a person's cremated remains before the ashes are buried.
Salt is believed to ward off evil spirits in Mayahana Buddhist tradition.
When returning home from a funeral,
A pinch of salt is thrown over the left shoulder,
As this prevents evil spirits from entering the house.
In Shinto,
Shio,
Literally salt,
Is used for ritual purification of locations and people,
And small piles of salt are placed in dishes by entrances to ward off evil and to attract patrons.
