Tower of Thorns
We spoke with Blackthorn Salt’s passionate founders Whirly and Gregorie about their love for tradition, sustainability, crystals and of course their impressive Tower of Thorns - a UK first and the only graduation tower in the world using sea water.
Blackthorn’s method of making salt is quite unique. Can you tell us about the process?
The Blackthorn Tower sits at Ayr, on the West Coast of Scotland, a mere stone’s throw from the sea itself and right on the site of traditional Ayrshire Salt works at Salt Pans Road. Each crystal comes from 100% seawater, gathered locally, and evaporated on the only working Thorn Tower in the world. We trickle seawater down a tower which is packed tightly with blackthorn twigs to evaporate it. We run the liquid around the tower, evaporating it by exposure to the wind and sun using no man-made power at all to increase its salinity from 3.5 to 22%: incredibly a whooping 24,000 litres of the original batch of 26,000 litres is dried off entirely naturally, leaving just 2,000 litres of concentrated brine for crystalising.
The second stage at Blackthorn is converting that 22% brine into crystals (which form at 25%). This takes place in the Pan House, where our organically approved Blackthorn crystals are grown incredibly slowly to ensure an exceptional mineral array. These work along with the bark tannins to enhance flavours unlike any other and lead to the distinctive character that Blackthorn has become so renowned for.
There are no chemicals or industrial processes used; no bleaching, seeding, or adding and the result is an organically approved, sustainable and natural salt which tastes of the sea, but also has a deeper mellowness to it and moreishly helps tastes last for longer.
Did you just decide one day to build this tower of thorns or was it an idea that developed over time?
Salt is part of our Master Salter and founder, Gregorie’s soul. With his family rooted in salt since the 1800s, it truly is what makes him tick. It was his drive and unwavering determination to discover a salt that paid heed to our heritage but would be worthy of tomorrow’s world that led to his investigation of the old ways of salt making. His curiosity was rewarded when, in 2005, he journeyed across Europe to visit graduation towers and witness just how mind blowing, effective, yet sustainable they really are. But would they work with sea water instead of rock brine? Inspired and sleepless, it was another 12 years before he was satisfied and started to build our very own Blackthorn Tower here on the West Coast. The first of its kind in the UK, and the first to use seawater, in the world, ever. Gregorie’s expertise and vision in all things salt is unparalleled, and Blackthorn Salt is the triumph of his fascinating odyssey.
What’s the upkeep of the tower like? How often do you have to replace the thorns?
The tower requires very minimal upkeep – apart from the regular checking and turning of the taps done by our master salters, the tower is pretty much self-sufficient. The increasingly salty seawater, or brine, helps to preserve the blackthorn bundles on the tower, as salt seals wood – think how long shipwrecks last... It is likely that we will need to replace the blackthorn in the end, but not because of degeneration of the blackthorn itself, more due to a build-up of calcium sulphate around the thorns (the first crystal to form from seawater) which may prevent the wind/air from passing through them. In the old rock brine towers, the blackthorns were replaced around every 7-10 years, however, sea water’s composition is so different, it may have an effect on the time, but we guess it will be around the same. We can return old thorns to the soil to provide sustenance for new thorns to grow. Those new ones themselves take 7-10 years growth and so match the cycle on the tower. Looking to complete circular economies and ensure that nothing is wasted is always a question we ask of ourselves and is incredibly rewarding as well as being fundamental to our method.
Can you tell us about a typical day in the life of a master salter?
We only have a small team of salters here at Blackthorn, Gregorie and Malky who really know their craft. Throughout the day, they meticulously check and adjust flow rates within the Thorn Tower to make sure it is working in harmony with the natural elements of sea and wind.
Weather means a lot to us at Blackthorn and depending on what form of dreichness, drizzle, wind strength and direction or sunshine that we happen to be experiencing for any given time, they will adjust the 54 wooden taps to make sure that the trickle-factor is tailored to that moment at that point on the tower. Running too fast if the wind is weak is pointless, too slow and it is wasteful. Then there are other checks to make, the valves and filters, the concentration levels and humidity effects.
In the Pan House, there is cleaning always, but some days are a deep clean, then maybe re-filling, crystal monitoring, agitating, experimenting, or harvesting; or it may be a clear, calm seawater gathering day and Blackthorn packaging day; maybe there is a Trade Tour or some design innovations we are looking at.
We are always, learning, looking for ways to improve, reduce our footprint and ensure that every box of Blackthorn Salt is the best it can be.
What dish does Blackthorn Salt work best with?
The beauty of Blackthorn Salt is that it works in harmony with any and all flavours under the sun. With our salt, “less is more” resonates. A pinch of Blackthorn can transform a dish – the saline tang alerts the palate then deeper enhanced flavours of other ingredients shine through. Mineral-packed Blackthorn Salt can make sweets sweeter, make mouthfuls more moreish, even bin the bite from bitterness. Blackthorn’s flavour profile has all the characteristics we look for in a salt – it gives an echo of the sea, but there is also a depth and mellowness which is provided by those precious minerals for the bitter, sweet, sour and salty elements and there is the bark tannins and earthiness to bring out the lasting sensation and more savoury umami flavours. The result is a salt which respects and elevates all the appealing flavour aspects of each mouthful, allowing them to resonate satisfactorily and leaving a lingering taste.
Folk, chefs and experts far more foodie and ambitious than we, have used Blackthorn for a multitude of purposes – from ferments and pickling to bread, chocolate, and ice cream making, cheese making, serving with an exclusive gin, or floating on a gazpacho, for use within a beer, pre-brining meat, salt baking and even gravadlax – but as a general rule, we suggest first trying it as a classic finishing salt.
What’s your favourite local?
As a business, we are local to Ayr, however as a family, the small village of Straiton is home, and there you can find a community shop, ‘Straiton Stores’, run on a not for profit but for the benefit of the community basis, by volunteers. The shop has been central to the village for many years and was astonishing in its efforts throughout the pandemic, especially with respect to the elderly. The store sells an array of goodies and we are honoured that Blackthorn Salt is there amongst them.
What is your ultimate food destination and why?
The uninhabited island of Fuday in the Outer Hebrides, having caught mackerel from the boat on the way across from Eriskay and South Uist, escorted by leaping dolphins. The mackerel could be accompanied by langoustine and crab from the pots that morning, all cooked and finished simply on a wee beach fire with butter, possibly some garlic, and a pinch of Blackthorn. There may be the bonus of locally picked fresh samphire and it could possibly be washed down with a glass of rose or a simple beer…
Why? Simplicity, fresh, idyllic surroundings, peace, cleanliness, joy of a Hebridean swim just beforehand and company of lovely friends, seals and eagles, we couldn’t ask for more! Although I think that Valentine Warner encapsulates some of this in a far more professional capacity at Holmen of Lofoten, the ‘Kitchen on the Edge’ and then there are always those pipe dream places like Geranium and Noma in Copenhagen, New York’s Eleven Madison Park and The Fat Duck in London or the Osteria Francescana in Modena which would just be a sheer honour to go to.
If you could travel through space and time, who would you have a drink with?
This is such a hard question – would we go back in time and meet with the early innovators of graduation towers? Or would we simply stay in the present moment and appreciate a drink with some of our foodie heroes? We initially thought we’d rather like a broad mix, a proper party with our family and friends. The opportunity to hear from Gregorie’s architectural heroes and environmentalists (John Muir, David Attenborough, Jane Goodall) ought not to be passed up, but it would also fun to add some characters across time and geography like Boudica into the mix as well. Some musical entertainment to go alongside would be essential – a line-up of all the top 25 bands of all time... the list could go on and on.
However, eventually we decided that tempting though all this was, most importantly, we would relish the opportunity to chat again with those who we have lost and wish we’d been able to spend more time with and a perhaps a few from the future who we may never meet or see fully grown.
What tunes do you listen to in the kitchen?
A large family of five, our music tastes are pretty broad and we can cover the full spectrum from Pink Floyd and Dire Straits to Ed Sheeran, Lewis Capaldi and Disney. However, there’s always a few favourites we rely on to keep the peace while cooking up a storm in the kitchen: a bit of Bohemian Rapsody by Queen and Shotgun from George Ezra generally does the trick with a touch of Snow Patrol thrown in for good measure!