The History of Salt

Let's take a closer look at the 2018 U.S. statistics. In salt consumption, road deicing accounted for 43% and the chemical industry took 39%. Food processing was 3%. Agriculture followed at 3%, general industry at 2%, and water treatment at 1%.

It would be a mistake to conclude from this that 'only 3% of salt is eaten.' Bags of salt sitting on supermarket shelves are lumped under the 'distributors' category (7%) in these statistics. Still, the general picture is clear: salt's biggest customer isn't the human tongue, but winter roads and chemical plants. And because these are figures for a single country—the United States—they do not represent a global average. Demand for road deicing can also swing wildly depending on that winter's weather.

The prices are also worth noting. In the same statistics, the average unit price per ton varied depending on its form: $10 for salt in brine form, $58 for rock salt mined from the ground, $100 for solar salt evaporated from seawater, and $200 for refined vacuum salt purified by boiling or vacuum evaporation. Chemically, they are all the same sodium chloride, yet the price difference spans twenty times. That doesn't mean the expensive salt is better. What creates the price isn't the substance itself, but how it is shaped and processed, and how far it has to travel.

What about production? Global salt production in 2024 was estimated at about 280 million tons. China led with 55 million t, followed by the United States at 40 million t and India at 28 million t. What's notable is that this is actually slightly down from 300 million tons in 2018. Because the compiling agencies and editions differ between the two years, one should be cautious about comparing them directly. Even so, salt production certainly hasn't been increasing in recent years.

Yet this common commodity comes with an unusual condition. Under its entry for salt, the U.S. Geological Survey notes that there are no substitutes and no recycling. In other words, it is something you cannot do without no matter how cheap it gets, and something nothing else can replace.

That is where the story ends up today: an abundant, cheap mineral, only a small fraction of which is eaten. But viewed against the whole span of human history, this ending was reached only very recently.

Traces of human salt-making go back earlier than you might think. At the Poiana Slatinei site in Lunca, Romania, evidence of Neolithic salt-making dates back to around 6000 BCE. It is one of the earliest confirmed instances of organized salt production. It is hard to pin down as the "world's first," however. Several candidate sites date to around the same period, and excavation reports span wide date ranges.

Similar evidence turns up in China. About 6,000 years ago, people of the Dawenkou culture along the southwestern coast of Bohai Bay boiled brine drawn from underground to make salt. The method was simple: boil down the salty water, and the moisture evaporates, leaving salt behind. The real issue was fuel. Because this simple task consumed staggering amounts of firewood, salt remained something that not just anyone could produce for a very long time.

There was also salt dug from the earth. The rock salt mines in Hallstatt, Austria, operated in earnest between the 8th and 5th centuries BCE. The artifacts recovered here are remarkable. Thanks to the salt preserving organic matter, miners' leather shoes, woven fabrics, wooden backpacks, and tools survived without rotting away. That is also why Europe's entire Iron Age culture of this era came to be known as the "Hallstatt culture." In a way, the mine itself proved what kind of substance salt really is.

Now let's look at this from the state's perspective. Salt is an ideal item to tax. Three conditions align. First, humans cannot survive without salt, so even if the price jumps, people cannot significantly cut back on buying it. Second, the places where it can be produced are limited: salt evaporation ponds, rock salt mines, and salt lakes. Third, control is simple if you just choke off those few passages.

There is one more advantage. If you embed the tax right into the price of salt instead of collecting it separately, buyers hardly notice they are paying a tax. Collection costs stay low, and public resistance remains minimal. This is a state monopoly. The state takes exclusive control over production or sales, collecting taxes hidden inside the price of the goods.

Yet there was one critical weakness in this control: seawater is everywhere. Where coastlines are long and the sun shines bright, people could simply make salt right on the beach. Later on, this very loophole would blow up in a famous, dramatic fashion.

In 119 BC, Emperor Wu of Han was in urgent need of money. The costs of warring with the Xiongnu had become impossible to bear. His solution was a state monopoly on salt and iron. The government established around 50 state-run salt works nationwide, staffing them with convict labor. Instead of extracting more taxes from the peasantry, he simply added a tax to the price of goods people had to buy anyway.

The true significance of this decision soon came to light. In 81 BC, after Emperor Wu had died, Huo Guang—the man holding actual power—brought the issue to the imperial court for debate: should the state monopolies on salt and iron continue?

The Confucians opposed them. Their argument was that the state should not compete with its people for profit. They also pointed out that iron tools produced by state-run workshops were shoddy. The Legalists fired back. Abolishing the monopolies, they argued, would only hand massive profits to wealthy merchants who could destabilize the empire, leaving military expenses to be covered by taxing the peasants once again.

The debate ended in a compromise. Only the liquor monopoly was repealed, while salt and iron remained under state control. Huan Kuan, an official of the time, later compiled the transcripts of this dispute into *Discourses on Salt and Iron* (*Yantie Lun*).

It was 2,000 years ago that the court gathered to debate whether the state should intervene in the market, and salt was the subject on the table. Even reading those arguments today, the core issues remain exactly the same.

The monopoly system was repeatedly revived after that. In the late 8th century, Tang chancellor Liu Yan overhauled the Salt and Iron Commission and rebuilt the salt monopoly. It is recorded that during the final 100 years of the Tang dynasty, nearly half of all state revenue came from salt. While this figure is repeated across general histories and cannot be traced back to year-by-year primary data, the scale itself is unmistakable. Roughly half of the imperial budget was being carried by a single seasoning.

The Ming dynasty took things one step further. In 1370, it instituted the Kaizhong system (*kai zhong fa*): merchants who delivered grain to frontier garrisons received *yanyin*, or official salt distribution permits, in exchange. The state obtained military provisions without spending hard cash, while merchants walked away with monopoly profits from salt. The monopoly rights to salt were effectively used as currency.

In Europe, salt even gave rise to cities. In 1158, Henry the Lion built a new bridge and market to redirect the salt toll revenues that had been flowing to the Bishopric of Freising toward himself. That site became the origins of Munich. While one cannot explain the birth of a city entirely through salt, who controlled the salt routes was unmistakably one of the catalysts.

In Poland, salt was essentially the state treasury. The Wieliczka and Bochnia rock salt mines, where full-scale mining began in the 13th century, provided up to one-third of the royal revenue in Krakow during their peak. Since the exact year for this figure cannot be confirmed, it is more accurate to read it as "such was the case at one time."

And actual wars broke out. From 1482 to 1484, Venice and the Duchy of Ferrara clashed. It all started when Ferrara attempted to take control of the Comacchio salt pans, which threatened Venice's monopoly on the salt trade. Under the Treaty of Bagnolo on August 7, 1484, Venice secured Rovigo in Polesine and the Po River delta. It was a case where nations went to war and borders shifted over a seasoning.

The most violent scene unfolded in Moscow. On June 1, 1648, the Salt Riot broke out. It was triggered by Boris Morozov, the tsar's closest advisor, who abolished several taxes and shifted the burden entirely onto salt. On paper, it was a neat tax reform. But urban dwellers and artisans survived the winter on salted fish. For them, a spike in the price of salt meant their entire dinner table collapsed.

On June 2 and 3, crowds marched on the Kremlin, and on June 11, Morozov was exiled to a monastery. Records state that 1,700 to 2,000 people died and 15,000 to 24,000 houses burned down. Yet the outcome of this event was not reform. The legal code drafted the following year actually cemented serfdom instead. Messing with the salt tax was not merely altering product prices; it was tampering with people's daily meals.

France's salt tax had a name: the gabelle. It began as war funding. Its starting point was a temporary levy placed on salt in 1229 when Louis IX took control of the mouth of the Rhône River, and in 1246, saltworks were built in Aigues-Mortes to fund the Crusades. Sources disagree on when this temporary levy hardened into a permanent tax. The years 1286, 1341, and 1360 all appear in records. What is certain is that over the course of the 13th and 14th centuries, a temporary wartime levy hardened into a permanent royal tax.

The real issue was not the tax rate, but the map. France was divided into six salt tax zones, and prices varied across each region. Looking at figures compiled in 1784 by Finance Minister Jacques Necker, salt that cost 31 sous in Brittany was 611 sous in Berry. That was about twenty times higher within the exact same country.

In the "Grandes Gabelles" region where the tax was heaviest, anyone over eight years old was required to buy a mandated quota of salt every year. It amounted to up to about 7 kg. It was salt you had to buy whether you ate it or not, whether you needed it or not. This region held one-third of France's population and paid two-thirds of the kingdom's salt tax revenues, yet consumed only one-fourth of the nation's salt. What drew such hatred was not the size of the tax, but this imbalance.

Faced with a twentyfold gap, smuggling was inevitable. Those who bought salt in cheap regions to sell in expensive ones were known as "faux-sauniers," and the agents who cracked down on them were called "gabelous." The gabelous searched homes and bodies without a warrant. Records even survive of women caught smuggling salt hidden inside false buttocks. Armed smuggling meant the death penalty, while unarmed smuggling brought 10 years in the galleys. Even though roughly 3,000 people were punished each year, smuggling never disappeared.

Did the Revolution eliminate this tax, then? Not at all. What the National Assembly did in 1790 was free those imprisoned for gabelle violations. Napoleon soon revived the tax itself, and the gabelle was only finally abolished in France in 1945. Counting only from that post-revolution measure, it survived for another 155 years.

In 1352, the traveler Ibn Battuta reached Taghaza, a salt-mining village in the heart of the Sahara. It had taken 25 days from Sijilmasa. The village he saw was bizarre. Houses were built from slabs of salt and roofed with camel skins. It was truly a salt village built upon salt. Each camel was loaded with two thick slabs of salt.

Here, we need to address a widespread myth: the story that in the Sahara, salt was traded for its equal weight in gold. In Ibn Battuta's records—a primary source for this trade—no such exchange rate exists. While gold dust was indeed traded in Taghaza, that did not mean an equal exchange.

What actually set the price was distance. The price of salt was determined primarily by transportation costs, jumping fourfold between Oualata and the capital of Mali. What was expensive was not the salt itself, but moving the salt. This distinction is crucial to our entire story. Salt was not expensive because it was a rare mineral; it was expensive because its sources were limited and transporting it was arduous.

Trade routes were not permanent. Taghaza was abandoned after the Battle of Tondibi in 1591, and the center of trade shifted to Taoudenni, 150 km to the southeast.

Out on the ocean, a shift was happening in the opposite direction. In the 17th century, inexpensive salt from Southern Europe began to be supplied to Northern European maritime nations. For the first time, salting and drying cod became commercially viable. Because salt cod could be loaded onto ships without spoiling for a long time, it became a cornerstone of the triangular trade linking the New World and the Old World. A slight drop in the price of salt was all it took to reshape the food map across the ocean.

Around the same time, England moved in the opposite direction. In 1693, under William III, England reinstated the salt tax, and in 1696, it doubled the rate. This tax would not be abolished until much later, in 1825.

After the British East India Company took control of Bengal, the salt tax rose rapidly. Through the era of Warren Hastings, Bengal's salt tax climbed from 0.3 rupees to 3.25 rupees per maund (about 37 kg). At the time, an agricultural laborer earned just over 3 rupees a month. Because the two figures come from different base years and regions, we shouldn't simply divide them and conclude that "a month's wage bought 37 kg of salt." Even so, they show just how heavily the tax was tilted, and in which direction.

When taxes are heavy, smuggling follows. In 1803, the British began setting up salt customs posts in Bengal, and these posts gradually linked together and grew into the Inland Customs Line that cut across the subcontinent. By 1869, it reached 4,030 km from the Himalayas all the way to Odisha near the Bay of Bengal. Along a substantial portion, they planted and cultivated thorny bushes. They had erected a living hedge.

Here too, we should be careful not to exaggerate. The living hedge did not cover the entire 4,030 km. As of 1878, the live hedge ran for about 800 miles, and the section kept in "good" condition or better was 411.5 miles. Still, the scale was astonishing. In 1872, the force guarding this line numbered 14,188 people: 136 British officers, 2,499 subordinate officers, and about 11,288 Indian staff. To stop the smuggling of salt and sugar, they drew a line across an entire continent.

This barrier was abolished on April 1, 1879. The reason is intriguing. Once the British gained control of Sambhar Salt Lake in Rajasthan and equalized tax rates across regions, the incentive to smuggle vanished. The tax did not disappear; the method of control had simply changed. Then in 1882, British India enacted the Salt Act, monopolizing the harvesting and sale of salt. It became illegal for an Indian even to scrape up salt along the seashore.

This is where the weakness of control mentioned earlier comes to the surface. India has a long coastline. Anyone can draw seawater. The very fact that the law tried to forbid it was itself the vulnerability.

On March 12, 1930, Gandhi left the Sabarmati Ashram and began walking. He set out with 78 people. After walking for 24 days, they reached the coast of Dandi on April 6, and at 8:30 a.m., he picked up salt, breaking the Salt Act. Most sources record the distance walked as 387 km. Depending on the source, it varies slightly between 385 km and 390 km.

The procession that had started with 78 people had transformed into an entirely different scale by the time it reached Dandi. The crowd that gathered exceeded 50,000, and the column stretched over 3 km. In the civil disobedience movement that followed, more than 60,000 Indians went to prison. At the time, the salt tax reportedly accounted for about 8.2% of British India's tax revenue. In purely fiscal terms, it was not an overwhelming share. What Gandhi targeted was not the tax revenue, but the legitimacy of a rule that turned even the salt on the seashore into someone else's property.

The Gandhi-Irwin Pact of 1931 included a provision allowing coastal residents to collect salt for their own consumption. The tax itself had not disappeared. And after being abolished, the 4,030-km customs line was almost entirely forgotten. In 1995, Roy Moxham, a conservator at a London library, stumbled upon a mention of it in the records, searched for its traces on the ground, and published a book a few years later in 2001.

Salt extraction technology was pushed to the extreme as well. In 1835, in Zigong, Sichuan, what was then the world's deepest salt well was drilled. It was about 1,000 m deep. It was not dug by machines, but by human labor—repeatedly dropping heavy chisels to crush the rock bit by bit. The Shenhai Well, which survives to this day, reaches a depth of 1,001.4 m, though it remains unclear whether both records refer to the exact same well.

There is another reason this well was so remarkable. As workers drilled down, they tapped natural gas, channeled it through bamboo pipes, and burned it as fuel to boil down the extracted brine. Remember how fuel was always the bottleneck in salt making? Zigong effectively pulled both the raw material and the fuel straight from the ground. Furthermore, this deep-drilling technique later influenced European oil drilling.

The true turning point came from chemistry. Starting in 1861, Ernest Solvay researched methods to produce soda ash from brine and limestone, and in 1864 he opened a factory in Couillet. By the 1890s, most of the world's soda ash was produced using this process. Soda ash is the fundamental raw material for glass, soap, and detergents. Behind the story of how glass windows became so affordable stood salt.

In 1892, the chloralkali process began operating on an industrial scale. This technique passes an electric current through brine to extract chlorine and caustic soda. Chlorine is used to produce PVC and disinfectants, while caustic soda is essential for manufacturing paper, soap, and refining aluminum. In 2022, global chlorine production reached about 97 million tons—an increase of about 2.8 times from 35 million tons in 1987.

This shift fundamentally altered the role of salt. In the U.S. statistics mentioned earlier, the chemical industry accounted for 39%, and 87% of that volume is supplied not as solid granules, but as liquid brine. Salt had transformed from a seasoning sold in bags into an industrial raw material flowing through pipes.

Around the same time, salt also became an instrument of public health. In 1922, Switzerland began distributing iodized salt canton by canton. Prompted by trials conducted by two physicians, the idea of preventing goiters through salt became national policy for the very first time. On May 1, 1924, iodized salt went on sale in Michigan in the United States, and that autumn Morton Salt launched nationwide distribution. The defining trait of salt—that everyone consumes a little bit every day—was tapped this time not for taxation, but for public nutrition policy.

Even into the 20th century, the salt tax remained alive. In fact, it dug in even deeper. In 1913, Yuan Shikai secured the Reorganization Loan with an international banking consortium, pledging the salt tax as collateral. A Briton, Richard Dane, led the Chinese Salt Administration until 1918; while there were only several dozen foreign employees, there were over 5,000 Chinese staff members. The nation's salt tax had become collateral for foreign debt. Even in 1931, the salt tax accounted for about one-third of the official budget revenue of the Chinese Nationalist Government, ranking as the second-largest source of revenue after customs duties.

Even when political regimes changed, the system endured. In February 1950, the People's Republic of China established the China National Salt Industry Corporation, reinstating the state salt monopoly. Then, after abolition was announced in 2014 and producers were permitted to sell directly to consumers starting in January 2017, the state salt monopoly that began in 119 BC effectively came to an end. It was an institution that had lasted well over 2,000 years. Even today, however, prices remain monitored, and most salt companies are still state-owned.

Other countries followed a similar timeline. France's gabelle was abolished in 1945, and India's salt tax was repealed in 1946 under Nehru. Taxes that had lasted for 700 years or for more than a century vanished in clusters around the mid-20th century.

Why around that time of all eras? Historical records do not explicitly state the reasons for abolition. Yet the state of salt during this same period is well shown by a single mine in Poland. Wieliczka halted its production of table salt in 1996. The reason it ended nearly 700 years of mining was not that the salt had run out. It was falling salt prices and mine flooding. A mine that once supplied one-third of the royal revenue simply lost its reason to mine because salt had become far too cheap.

Today, this mine lives on in a different way. Reaching a depth of 327m with 287km of tunnels, it was one of the twelve sites inscribed on UNESCO's inaugural World Heritage list in 1978, and in 2025, it welcomed a record-high 1.91 million visitors. A place that once sold salt has become a place that sells scenery.

To sum it up: rarely did a salt tax end through rebellion alone. The Moscow riots only entrenched serfdom further, and in France, the tax survived for another 155 years after the measures following the revolution. In places like India, independence brought the tax to an end. While circumstances varied from country to country, they shared the fact that multiple nations let go of it all at once in the mid-20th century. It was a revenue source the state would never have surrendered in earlier times. It is worth noting that this coincided with the era when salt was losing the value that made it worth controlling.

For a long time, Korea relied on jayeom—boiled salt. It was made by pouring seawater into large cauldrons and boiling it down with firewood. Because it required so much fuel, it was never cheap. Right up through the Joseon Dynasty, most salt in Korea was produced this way.

State monopolies were hardly an unfamiliar concept either. In 1309, King Chungseon of Goryeo enacted the Gakyeombeop (榷鹽法), seizing salt-boiling cauldrons for the state and setting fixed sales prices. It shared the same underlying logic as Emperor Wu of Han's salt monopoly discussed earlier, even echoing the same official justification: "preparing for state expenditures."

Things began to change during the modernization period. In 1907, Korea's first modern solar salt flat was built in Juan, Incheon. By trapping seawater in vast salt pans and evaporating it using only sunlight and wind, it required virtually zero fuel costs. In exchange, it needed expansive tidal flats and clear weather.

Historical records differ on who should be credited with establishing this salt flat; some credit the Korean Empire government, while others point to the Japanese Residency-General. What is certain is that an experimental salt pan was established in Juan in 1907, and its scale expanded dramatically afterward. It grew to 260,000 pyeong between 1908 and 1911, and expanded further to 370,000 pyeong between 1917 and 1918.

Salt became a monopoly item here as well. On April 1, 1921, the Monopoly Bureau of the Japanese Government-General of Korea was re-established to oversee tobacco, salt, and ginseng. In 1942, the Chosen Salt Monopoly Ordinance was enacted, firmly establishing salt as a statutory monopoly. This system lingered for some time even after liberation until it was abolished in 1962, and the salt business was fully privatized the following year.

What followed was even stranger. Enacted on October 28, 1963, the Salt Management Act defined salt as 'crystals containing 40% or more sodium chloride.' Rather than being defined as an edible product, it was classified purely by its chemical composition. Under this law, solar salt was treated as a mineral. In 1996, regulatory oversight of edible salt moved from the Salt Management Act to the Food Sanitation Act, but solar salt was left behind.

After undergoing rigorous analysis beginning in 2005, the Salt Management Act was finally amended in November 2007, and on March 28, 2008, solar salt was officially listed in the Korean Food Code. Counting from 1963, it took 45 years. Until then, the term 'solar salt' did not even exist in the Salt Management Act; the word entered the statute for the first time with the 2007 amendment. Something served on dinner tables every day had legally remained a mineral on paper for 45 years.

This isn't just something to laugh off. Salt has two distinct faces: it is a food, but it is also an industrial raw material. As seen in the earlier US statistics, the vast majority of salt went to factories. It is up to each country to decide which regulatory framework to apply, and when that decision misaligns, gaps like this emerge.

The salt flats themselves also dwindled. After 1970, rapid industrialization and urbanization forced many salt flats to close, and today only tidal salt flats along the west coast, such as those in Sinan and Buan, remain well known.

Let's look at Uyuni in Bolivia. It is a salt flat covering an area of 10,582 km², with salt reserves estimated at about 10 billion tons. Yet the amount actually harvested is less than 25,000 tons per year. They are barely touching a tiny fraction of the reserves. Today, the true value of this place lies not in its salt, but in the lithium lying beneath it. As of 2024 tallies, Bolivia is estimated to hold about 22% of the world's lithium resources. The value of salt flats has effectively shifted from salt to another element.

Just because something is cheap does not mean supply is secure. As of 2018, the United States relied on net imports for 28% of its salt. Its import sources, averaged from 2014–17, were Chile at 38%, Canada at 28%, Mexico at 11%, and Egypt at 4%. It is a setup where nearly 30% of a commodity that has no substitute and cannot be recycled is brought in from abroad.

Let's also touch upon health. Here, we will stick strictly to the facts. The World Health Organization recommends that adults consume less than 2,000 mg of sodium per day, or less than 5 g of salt. In 2021, the global average daily intake for adults was estimated at 4,278 mg, or about 11 g of salt. In 2023 alone, deaths associated with excessive sodium intake were estimated at about 1.7 million people. Note that this is an estimate of association, not a confirmed figure of direct causation.

Thresholds also vary by institution. The American Heart Association's recommendation of 1,500 mg per day is stricter than that of the World Health Organization. Within academia, real disagreements persist as well. A 2016 review noted that studies supporting the cardiovascular benefits of sodium reduction and those disputing them have accumulated side by side. Apart from the recommendations of international organizations, the specific debates are still being settled.

Finally, let's wrap up with three things worth watching.

First is production volume. Global salt production actually declined from 300 million tons in 2018 to about 280 million tons in 2024. Because different tracking organizations compiled the data, comparing the two years directly requires caution, but production is at least not growing. The trend of salt cheapening in the 20th century connects directly to the transformations seen in earlier chapters. If this number starts to rise again, the reason will likely lie not in seasonings, but in the chemical industry.

Second is the role of salt flats. As more locations like Uyuni are valued for lithium rather than salt, local political and environmental discussions also pivot around a different axis.

Third is the debate surrounding sodium. How international recommendations, national policies, and academic disagreements are resolved will directly shape food labeling and processed food standards.

For 2,000 years, salt was a resource that states held tight and never let go. Today, we scatter it across icy winter roads and flush it down industrial pipes. But becoming cheap and becoming unimportant are two very different things.