MEET THE MAKERS
Using a historical technique involving a structure called a graduation tower, Gregorie Marshall has brought salt production back to Ayrshire
The striking structure standing on the Ayrshire waterfront looks like a giant art installation. But the timber A-frame, slotted with spiky bundles of blackthorn branches, has a practical purpose: to produce sea salt.
It’s the work of master salter Gregorie Marshall, founder of Blackthorn Salt, who was inspired by a visit to Germany and Poland to view ancient graduation towers once used to produce rock salt. Having previously trained as an architect, Gregorie drew up plans for a similar structure, but for sea salt instead.
Salt is as much a part of Gregorie’s heritage as Ayrshire’s — in addition to Blackthorn, he also runs Peacock Salt, a company set up by his great-grandfather in 1874. But while Peacock —a salt importer — has thrived for nearly 150 years, domestic salt production in Scotland has decline during this time, with the last Scottish pan house closing down in 1959.
Now, thanks to Gregorie, salt is being produced in Ayrshire once more, using nothing but west coast seawater and a traditional method, which, although new to Scotland, dates back to the sixth century. Seawater, pumped to the top of the tower, trickles slowly down through the blackthorn branches, the increased surface area created by the thorns accelerating the evaporation process. The cycle is repeated until the salinity of the water has risen from 3.5% to about 22%, at which point the resulting brine is then pumped into the neighbouring pan house, where it’s heated. At this stage, the pyramid salt crystals form.
“We worked with the University of Strathclyde to determine the best angle of the tower for maximum evaporation
