The oldest known salt mine is located near the city of Provadia, Bulgaria. The salt mine is called Solnitsata, and it began producing salt as early as 5400 B.C. In 2700 B.C., a treatise on pharmacology called the Peng-Tzao-Kan-Mu was published, including descriptions of 40 different kinds of salt and descriptions of salt extraction methods. Egyptian artwork from as early as 1450 B.C. depicts salt. Salt was extremely important through most of human history, but became exceptionally so towards the middle ages and the renaissance. Venice became a wealthy city due to its sole control and monopolization of salt mines in the area. Other notable cities followed suit: Tuzla, Bosnia-Herzegovina (tuz means “salt” in Turkish), and Salzburg, Austria (Salzburg translates to “salt fortress” in Austro-Bavarian). Salt has even been responsible for toppling regimes. At the end of the 16th century, the Dutch Revolt was successful in bankrupting King Philip II of Spain due primarily to their blockade of the Iberian salt mines. Taxes on salt, called the gabelle in France, happened continent-wide and financed most monarchs during that time. Salt was such a powerful economic driving force that taxes on it skyrocketed from 14 times the cost of production to 140 times the cost of production between 1630-1710.
The easiest (yet most dangerous) method of salt extraction is salt mining. Shallow sea basins with little to no water exchange with lakes, rivers, and oceans will dry up over time in an arid climate. As the water evaporates, it leaves behind the salt contained within. Winds will deposit clay and dust over top of the salt deposits, and tectonic forces will push the deposits further beneath the earth. The salt is extracted by digging down to the pocket and manually extracting the salt. Salt mines theoretically could be up to 100% salt, but usually contained between 40-70% salt. Salt mining was highly lucrative; one miner could mine enough salt to feed one thousand families per year. Salt mining was dangerous due to rapid dehydration caused by contact and inhalation of salt; as such, mining was done by slaves or prisoners.
Soon, between the decreasing availability of rock salt mines and the increasing technological abilities of the time, it became increasingly easier to manufacture salt by evaporating seawater or inland brine pools. The water would be collected in large, shallow clay bowls (or later on, metal tins) and heat would be applied to evaporate the water, leaving behind salt. This process was much faster and safer, as the manufacture of salt did not have to happen deep underground.
Food – Salt was used to season food, as well as preserve it. For most of history, the only way to preserve meats was to submerge them in a saltwater brine or use a dry salt rub. The salt draws water out of the meat through osmosis, inhibiting the growth of microorganisms. Salted meat and fish was a staple of nearly every culture’s diet through all of history.
Religion – Salt is used heavily in religious rituals across the globe. In Judaism, religious offerings usually include salt. There are numerous mentions of salt in the Bible as well. The word “salvation” comes from “sal”, the latin word for salt. A Shinto tradition is for Sumo wrestlers to throw salt in the ring before a match in an effort to drive away evil spirits.
Currency – The word “salary” was coined by the Romans. A salary was paid to soldiers so that they could buy salt. Salt was also routinely exchanged for goods and services throughout history and across cultures.
“History.” History | Salinen. N.p., n.d. Web. 18 June 2014.
“History of Salt.” History of Salt. Akzonobel, n.d. Web. 17 June 2014. https://www.akzonobel.com/saltspecialties/salt/salt/
“History Of Salt.” History of Salt. N.p., n.d. Web. 17 June 2014. http://www.saltworks.us/salt_info/si_HistoryOfSalt.asp
“Salt Uses & Tips.” America’s Sea Salt Company. N.p., n.d. Web. 19 June 2014.
Thomas H. Maugh II | Los Angeles Times. “Bulgarians Find Oldest European Town, a Salt Production Center.” Los Angeles Times. Los Angeles Times, 01 Nov. 2012. Web. 19 June 2014.