We can only speculate when humans first started using salt. It’s likely that prior to the invention of agriculture, hunting and gathering tribes used salt to cure meat, preserve fruits, and flavor vegetables, but there is no firm history in the archeological record of this. Nor would there be, as the cultures moved and migrated, never needing to establish an organized supply of salt.
The first history of systematic use of salt is with the Chinese, who are the oldest literate culture still in existence and have written history describing about 8,000 years back. Chinese historians write of a magic lake of salt in the northern province of Shanxi, a high desert region not unlike the San Luis Valley.
High in the mountains of Shanxi is a body of salty water, Lake Yuncheng, over which Chinese tribal warfare is legend, all for control of the Lake’s salt. The abundance of human bones around the Lake, together with the legends, have convinced historians that Lake Yuncheng was likely the first salt source for an agricultural, and well organized human culture.
The first recorded history of salt production in China goes back about 3,000 years to the Xia dynasty. The techniques for salt production involved placing sea water in large clay pots and boiling by fire, or evaporating by sunlight, to reduce the salt crystals from the liquid.
When iron came into common use some 3,500 years ago, the Chinese began to use metal pans for salt production. The legendary Guo Zong, produced both fish and salt, and the these two enterprises were common together for the next 2,000 years, as preservation of fish with salt was a true innovation.
However, the Chinese did not sprinkle salt on their food, perhaps because salt was dear and expensive, so salt was used primarily as a means of preservation, being added to soy, to make soy sauce, and to vegetables in the pickling process.
As vegetables begin to decay, the carbohydrates (sugars) break down and yield lactic acid, which also serves as a preservative, but air borne yeasts and bacteria generally get in the mix and the vegetables begin to putrefy. This can be stopped by adding salt at the rate of only one percent of the weight of the vegetable and sealing the mix in a container with no oxygen. The result is lactic acid fermentation, or pickling.
Though salt is common today, for human cultures emerging with agricultural economies, salt was rare and valuable. It was used in pickling, but also to keep fish from rotting, and brine solutions were used around granaries to discourage rodents and insects. The Chinese built elaborate bamboo piping and trellis systems to move brine through entire provinces, remnants of which still stand. As we will see in upcoming columns, salt was also important and strategic to the development and expansion of Western culture. ❖