Salt — chemically sodium chloride (NaCl) — is a mineral that has been central to human food systems for thousands of years. It serves as a flavour enhancer, a preservative, and a functional ingredient in processes like fermentation, curing, and bread-making. Historically, salt was so valuable it was used as currency and was a driver of trade routes and geopolitical conflict.
Table salt, sea salt, rock salt, and flake salt are all the same compound but differ in crystal size, trace mineral content, and processing. Specialty salts like pink Himalayan salt or fleur de sel command premium prices largely for texture and appearance rather than meaningful compositional differences.
Salt is produced in enormous volumes globally — over 300 million tonnes per year — though only a fraction goes to food use. The majority is consumed by the chemical industry and for road de-icing in cold climates.
How it's produced
Salt is obtained through three main methods. Solar evaporation is the oldest: seawater or brine is channelled into shallow ponds and left to evaporate under sun and wind, leaving salt crystals behind. This method dominates in warm, dry climates including parts of Australia, India, and the Mediterranean.
Rock salt is mined directly from underground deposits — ancient seabeds buried by geological processes — using conventional mining or solution mining, where water is injected into the deposit and the resulting brine is pumped to the surface. Vacuum evaporation, where brine is boiled in sealed vessels, produces the fine-grained table salt most common in household shakers. Australia is a significant salt producer, with large solar salt operations in Western Australia and South Australia.
What it costs the planet (per kilo)
≈ Estimated from its category — typical for salt & minerals, not measured for this item yet. Sources & methods →
What comes from this
Your household's take
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