Sea Salt - Historical Production

Historical Production

Mineral salt has long been mined wherever it was available; the salt mines of Hallstatt go back at least to the Iron Age. However, there are many places where mineral salt is not present, and the alternative coastal source has also been exploited for thousands of years. The principle of production is evaporation of the water from the sea brine. In warm and dry climates this may be accomplished entirely by using solar energy, but in other climates alternative and often expensive fuel sources must be used. For this reason, modern sea salt production is almost entirely found in Mediterranean and other warm, dry climates.

Such places are today called salt works, instead of the older English word saltern. An ancient or medieval saltern could be established where there was:

1. Access to a market for the salt,
2. A gently-shelving coast, protected from exposure to the open sea,
3. An inexpensive and easily worked fuel supply, preferably the sun,
4. Another trade such as pastoral farming or tanning which could benefit from the nearness of the saltern (by producing, for example, leather or salted meat) and in turn provide the saltern with a local market.

In this way, salt marsh, pasture (salting), and salt works (saltern) enhanced each other economically. This was the pattern during the Roman and Medieval periods around The Wash, in eastern England. There, the tide brought the brine, the extensive saltings provided the pasture, the fens and moors provided the peat fuel, and the sun sometimes shone.

The dilute brine of the sea was largely evaporated by the sun, and the concentrated slurry of salt and mud was scraped up. The slurry was washed with clean sea water so that the impurities settled out of the now concentrated brine. This was poured into shallow pans lightly baked from the local marine clay, which were set on fist-sized clay pillars over a peat fire for the final evaporation. The dried salt was then scraped out and sold.