The article examines data from archaeological and written sources regarding the ancient salt-making industries in Georgia. It also discusses the technological processes used to produce table salt from seawater and saline water.
Salt has played a significant role in human development since ancient times. Its all-encompassing influence on the living environment was largely determined by the presence of sodium and chlorine, essential components of the human body that play a crucial role in metabolism.
In ancient Georgia, salt was predominantly used as a primary food component for both humans and animals. Additionally, it was utilized for various economic purposes, such as preserving skins for storage.
According to various written sources, salt was brought to Georgia from other countries since ancient times; however, it appears that salt extraction also took place within Georgia.
The primary sources of salt were salt mines and saline water solutions, which could be either artificial (created by dissolving rock salt or natural salt deposits) or natural (derived from seawater, salt lakes, and salt springs).
The stone fragments were first crushed, and after manually removing mechanical impurities, they were used as intended. Sometimes, salt was purified by dissolving it in water and then recrystallizing it. As for saltwater—whether from the sea, lakes, or springs—the final product was obtained as a precipitate through evaporation.
It is worth noting that Vakhtang VI (1675–1737), in his work Chemistry, distinguishes between rock salt and self-precipitated salt (i.e., malex, obtained through the evaporation of brine), which he refers to as “khashur.”
The extraction of salt from seawater in the territory of Georgia is evidenced by the remains of ancient salting plants discovered through archaeological excavations. In particular, evidence from the Eneolithic period BCE was found near the port of Ochamchire. In this area, dating to the 1st millennium BCE, the presence of salt-evaporation pools for extracting salt from seawater was confirmed, clearly demonstrating that salt extraction from seawater has been practiced in the territory of Georgia since aIn calm weather conditions, these growths remain on the surface of the solution for quite a long time, despite their enlargement, and only begin to sink when water penetrates their structure.”
The scientific literature provides well-documented insights into the technology of extracting salt from seawater. With this knowledge, we can readily deduce the working principles of the Ochamchire salting plant. In the case of evaporation of solutions in open space, a solution less often releases crystals, which form a kind of pyramidal, four-sided funnel. In general, the separation and growth of such crystals are influenced by slow heating (which occurs naturally under normal conditions) and the process mainly occurs on the surface of the solution, also driven by sunlight, which only heats these upper layers. That is why crystallization starts from the top, and the formed crystal, which keeps the upper side dry, remains on the surface until its upper side becomes wet. After wetting, these crystals, as we mentioned, sink, and new crystals form on the surface of the solution in their place. Unlike the center, the crystals at the sides stick together and therefore do not sink. As the water level decreases due to evaporation, a crystalline crust forms, creating a funnel-like surface layer. After some time, the solution is drained from this crust, and the finished product is used for its intended purpose. This crust contains almost all of the table salt, while impurities such as bitter salts of magnesia and calcium sulfate remain in the solution.
Salt mining was carried out in the Ochamchira region in a similar way, and it is clear that these practices must have been passed down to the population of subsequent centuries. However, we do not find any facts confirming this due to the lack of appropriate sources. In this regard, the 18th century was somewhat fortunate, as there are several interesting reports from that time.
In 1771-1772, Guldenstedt (1745-1781) visited Georgia, and with the help of Emperor Erekle II, he studied the mineral resources and mineral waters of the region in great detail. He is the author of an interesting account of a salt spring he discovered near the village of Machkhaani in Kakheti. According to this account, ‘a spring of edible salt emerges from sandstone. It is one foot in diameter and flows calmly without bubbles. In March 1772, it did not overflow its banks, though this could have happened at other times, as brackish water is common around it. The inhabitants used it as needed.
As we can see, Guldenstedt examined this spring quite carefully and even noted that its flow varied depending on the season and year (this conclusion was made possible by the salinization of the adjacent territory, which could only result from the periodic overflow of the spring’s banks). At that time, when studying mineral waters, it was considered necessary to record both seasonal changes and the traces of its influence on the surrounding environment. Guldenstedt also adheres to this practice and provides such information regarding the mentioned spring. However, the most important detail in this information is that the local population used it ‘as needed.’ This suggests that they exploited this deposit. Unfortunately, Guldenstedt does not specify how this salt was extracted—whether naturally, by collecting sedimentary ‘khashuri’ on the banks of the springs, or artificially, by placing the water from this spring in a special basin and allowing it to evaporate over time.
The second option should be preferred, as it actually confirms the possibility of obtaining salt artificially. According to another account by Guldenstedt, King Erekle had a salt factory in Tbilisi.
It is clear that in this factory, salt must have been obtained artificially.
Several salt springs were known near Tbilisi (near Lake Kojermi, near the spring in the village of Mijari, near the village of Mukhrovani, etc.), so the Erekle factory must have used one of these springs as raw material.
The primary product was obtained on-site by draining the salt-containing water into special ponds. The resulting precipitate was then transported to the factory (transporting the salt-containing water itself was, of course, unprofitable). There, it was dissolved in hot water, and the impurities that precipitated on the surface during the boiling process were removed by skimming. In our opinion, the secondary aeration process should have been carried out until the solution was nearly dry, as, in such a case, the bitter salts of magnesia would also have been included in the resulting precipitate, which would have significantly deteriorated the quality of the product. To avoid this unprofitable outcome, the separation of the salt from the solution should have been done in its thickened state before the solution became completely dry.
The process of separating salt from the solution was to begin once a sufficient amount of precipitate had accumulated in the solution thickened by evaporation. This precipitate was transferred to another vessel in a wet state and dried by heating. The finished product was then used for its intended purpose.
Obviously, the work of the Erekle factory was based to some extent on the experience of its predecessors, and in fact, a tradition was being continued here, the foundations of which were laid much earlier, likely existing before the factory’s activities began.
The existence of salt mines in ancient Georgia further demonstrates that production processes based on chemical methods were widespread in our country since ancient times.
Author: Raul Chagunava
Translated from Georgian by Elene Shengelia.