The Science of Making Sea Salt

Wight Salt Science will explore natural processes; the water cycle, evaporation, and what happens from start to finish in this process of harvesting the Salt Crystals

We will look at the Salt Crystals themselves, what they are made up of, and how Sea Salt and the process of harvesting it differs from inland mined table salt.

We will also discover ways of reclaiming the pure water that evaporates in this process by using a Solar Still. Solar Stills are simple but totally effective in separating salt from seawater or impurities from polluted water to make it drinkable.

We are using natural evaporation methods to get Sea Salt. The Isle of Wight has arguably the best climate in the UK but it isn’t based in the Mediterranean with a warm climate most of the year, so some creative thinking was required as my aim was to harness as much natural energy as possible.

At my plant in Yafford, about 10 miles from Ventnor, a small microclimate is created using a large polytunnel. The clear thermal liner over the polytunnel traps any heat from the sun and increases the temperature inside the tunnel making it hotter than the outside. This creates ideal conditions for the Seawater to evaporate in wide shallow tanks.

I will be setting up a webcam very soon inside the tunnel so that you can all see;

• The process of slow evaporation in real time and in a time lapse.

• How a solar still works to reclaim the fresh water from the Sea Water, effectively demonstrating key aspects of the water cycle in miniature form.

Solar Stills are used by the Navy at sea for an emergency water supply and in hot countries, where a polluted water supply can quickly be made safe and drinkable.

This is one example of how a Solar Still works:

Solar Still Diagram

The Suns rays heat up the area inside the glass which causes the water to heat as well. Pure water molecules evaporate into the warm air to rise and condensate onto the glass. The water then trickles down the sides of the glass into collection troughs. Eventually all the clean pure water is evaporated and collected leaving the impurities or salt (if seawater) behind.

Seawater is approximately 3.5% salt and other trace elements, so in 1000 litres there is approximately 35kg of salt with up to 965 litres of pure, distilled water that potentially could be claimed back.

Wight Salt Science will be an on-going exploration to innovate harnessing as much natural energy as possible.

See the developments as they happen by following us on Instagram.