Have you ever wondered how salt is made? It can be naturally occurring, due to the evaporation of seawater, which leaves salt deposits that can be easily collected. This is probably how early humans first encountered the mineral sodium chloride and began using it to preserve food. Salt production is done in three ways – through seawater evaporation, rock salt mining and brining.
Photo: Fine Dining Lovers artwork
How is salt produced?
These days the modern method of salt production replicates the natural one, but at scale. Seawater is pumped into large evaporation ponds where the natural process of solar evaporation can take place aided by the wind. This requires a constant high temperature, long exposure to the sun and low rainfall. For this reason, the commercial production of salt is concentrated in areas around the Mediterranean, in Africa or in the southern coastal states of the USA.
Seawater naturally contains high salt content, but the salt yield from the water can be increased by the process of salt brining. This involves pumping seawater underground to dislodge and dissolve salt deposits in the underlying bedrock. The saltwater is then surfaced and treated with vacuum evaporation to remove mineral impurities, before the brine is then pumped into shallow ponds or salt bed. Most table salt is produced in this way and as it produces nearly pure sodium chloride salt crystals, it is inexpensive and effective.
Rock salt is also present in the underlying bedrock and is located in veins underground. The salt is the remnants of bodies of water that have long since dried up, leaving the rock salt deposits behind. The salt is mined in the traditional way, using dynamite to blast off large boulders of salt, which are then crushed before being sent to the surface. As rock salt usually contains large amounts of impurities, it is generally used for industrial purposes, like de-icing roads.
Salt varieties
Regular table salt is the most common salt you can find as a condiment for your food, but there is a myriad of different flavoured and specialised salts, including sea salt like Maldon sea salt, which is made using tidal movements in England, all with different flavouring effects for different foods.
What is kosher salt?
Salt has always been a foundational substance for human civilisation and many of the oldest human settlements were established because of their proximity to salt beds or salt mines. Salt has been used to cure and preserve food for millennia as well as a currency and crucial trading commodity. Today salt is much easier to produce at scale meaning it is considerably less valuable, but no less important to the way we eat. Pass the salt.
