Scotland’s Larder: Meet Gregorie Marshall from Blackthorn Salt in Ayrshire

As part of our Scotland's larder series, we talk to Gregorie Marshall about his unique Blackthorn Salt Tower in Ayrshire.

Published 8th Sep 2020
Updated 31 st Oct 2023

This humble condiment, salt, is a staple of every kitchen cupboard and as part of our Scotland's Larder series we meet Gregorie Marshall of Blackthorn salt.

Gregorie and his wife Whirly are the owners of a unique structure which stands proud in the coastal landscape, looking like something out of a fairy-tale or a set from a Tim Burton film.

This couple have turned a salty obsession into an artisan business by building a unique graduation or salt evaporation tower, and in so doing have reintroduced a historic industry back to this corner of the world.

Blackthorn Tower set in the Ayrshire landscape.

Having created such an impressive structure, it should come as no surprise that Gregorie has a background as an architect before taking the decision to join his family's salt-making firm.

He is now the fifth generation of his family to be involved in the salt industry and just happens to be the current managing director of Peacock salt as well as running Blackthorn Salt as a standalone business.

The company was founded by his ancestor, John Craig Peacock, who was originally involved in the shipping industry on the Clyde.

Initially the company sold all manner of sailing goods, including rope, but as salt was the main method of food preservation at that time, they soon specialised and began shipping from Spain and delivering it to Newfoundland amongst other places.

Now Peacock salt sells anything from rock salt to Himalayan salt and Epsom salts in industrial quantities, to be used in everything from de-icing to cosmetics and fish processing and the food industry.

At age 35, Gregorie became the managing director of Peacock Salt, but prior to that he wasn't always that keen to be involved with the family business, as he says: " I stuck my head, in the sand."

Gregorie met his partner Whirly, a lawyer, at a music festival on the Isle of Jura. They got married and had three children, Rory now aged  (11), and two girls Lara (10) and Millie (6).

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They realised their life had slowed down a bit, so they were both happy with the decision to move to Ayr, as Gregorie  explains: " it was the right time, the sensible time and a good time to join the company, with change happening, within the business.

"Now, I'm absolutely glad we did, 100 per cent glad."

View from inside the tower looking out through the Blackthorn twigs.

The Blackthorn Project

Gregorie first became aware of salt evaporation or graduation towers about 15 years ago and after some research headed to Germany to visit them.

Seeing them up close, began his obsession with tower building began and it has taken them 15 years to get to the point they are at now, with a fully functioning salt graduation tower producing a finished product.

In the 6th Century, the first graduation towers used straw to filter the brine, but technology matured over the following centuries and blackthorn bushes became prized for their hardiness and longevity.

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Today the towers in Germany and Poland, which no longer actively produce salt are run as spas, inviting tourists and locals with respiratory difficulties to come and breathe the brined air.

Although Gregorie hasn't done any specific covid therapeutic research he says: " salt pretty much kills most things, so it can't be bad."

On his return home Gregorie began to dream up his own Blackthorn project, which was "my initiative, from the start," he said.

These massive European structures appealed to his architectural side so he started the planning, asking 'how could we do one here?'

Then the real hard work began in earnest, to realise the vision of making artisan salt from seawater in Scotland in an environmentally friendly manner.

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With lots of help from Strathclyde University, research into the exact forces at work and how the Blackthorn twigs aid the evaporation process of salt seawater had to be completed.

Then they could begin to look at different locations and work out the best conditions for the process to work, in all types of humidity and weather.

The brine is pumped through the tower and moved by a series of taps.

The process

Scottish West Coast seawater is slowly trickled down through the enormous thorn tower whilst the wind evaporates excess water.

The salt water is dribbled through 54 wooden taps and a series of channels, which are adjusted daily according to the weather conditions, to maximise evaporation, producing a more concentrated brine.

The final stage is to take the salty brine, add some gentle heat to create crystals of sodium chloride with natural trace elements.

Although it is the same simple process as hanging your up clothes outside to dry,  Gregorie explains that: "It is a dark art, which depends on how fast the wind blows, air humidity and wind direction with the ideal being 45 degrees from the prevailing wind, however, the Scottish weather is not always predictable."

Gregorie added: "the blackthorn twigs increase the surface area and create smaller droplets of water meaning more air can pass over it, but we are learning every day so I still don't know exactly how much salt it will produce, but we will work it out.

"It keeps us guessing, I'm one for new things and I'm always learning, which is part of the fun. I'm still pushing to get it to work better"

The West coast seemed an obvious location to build, on the aptly named Saltpans Road in Ayr, because it was near his office and warehouse facilities.

However, as the seawater in Ayr is too diluted and filled with silt washed down by the Ayr river, Blackthorn salt has to source 28000 litres of seawater at a time from Troon.

Gregorie said: "you are allowed to take so much seawater before you have to ask the Queen for permission, but we are nowhere near that level at the minute."

The best time for collection "depends on level of the tide, and still settled weather. Naturally, seawater is around 3% saline solution, 3.5 % is ideal" " said Gregorie.

The water is then transported to their holding tanks, before being filtered and circulated. It is then pumped to the top of the tower at a rate of 1000 litres per hour, moving slowly through the tower until the salty brine reaches around 22% salinity.

It is then pumped into the pan house which uses double-skinned pans for the next stage, the heating process. When the brine reaches 26% strength, the salt crystals begin to form.

The whole process Gregorie explains: "takes about 5 days, but you need to keep an eye on it.

" I'm not quite happy, I'm still searching for the perfect size of salt crystal and tinkering with that part of it. To find the crystal size we want, make it easy it is to crush with your fingers, delicate enough not to leave clumps but still looks nice.

"The finished product has a slightly golden colour which comes from the tannins of the blackthorn, originally we were aiming for pure white but that removes the trace elements magnesium and calcium and you lose the taste," he said.

Blackthorn salt crystals

Time & Tide

The area has a long but obsolete industry with historic salt pans, a stone’s throw away from the Blackthorn Tower at Newton, Craigie and Alyson salt pans, you can also see the old derelict Maryburgh salt pan houses (now Maryborough) which remain standing only one mile away.

In the past, all around Scotland's coastline, fires were ablaze to simmer seawater to create salt which was one of the highest value commodities of the day.

Gregorie said; "we have restored an industry with a modern twist, to on an old process which was energy-intensive. We are making it more sustainable."

Environmental concerns are at the heart of the project, to create an entirely natural product and building the tower took a lot of effort, Gregorie explains that no one has done it ever before.

He adds: "Archie and his craftsmen took on the challenge, that no one else would. The frame is made from renewable Scottish wood,  Larch, and Douglas fir timbers and some of the blackthorn bushes were sourced from Gledpark in Dumfries and Galloway."

Blackthorn is a hardwood with lots of spikes, the ideal size of bushes in the tower take 7-10 years to grow and although they don't know exactly how long the current bushes will last, the Blackthorn they used was about 7 years old. In the future, they are hoping to grow a field of blackthorn and to harvest them in 7 years, Gregorie said, "but all in good time."

The bonus might be a bumper harvest of Blackthorn berries, which the couple would love to see turned into Sloe gin, as a by-product of the salt-making process.

Onsite they have an electric pump, powered by solar panels and the process is very energy efficient, Gregorie said, "we'd love to add a windmill but costs would escalate so practical me, had to make the call about what was feasible."

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Even the packaging has been lovingly created. Gregorie explains that the box design has no plastic, and finding a box that was easy to open and could be reused was a challenge, he said; "eventually we got there, but it wasn't easy."

The stylish pack features a blackthorn flower designed by Graven images, duo Janice Kirkpatrick and  husband, Ross Hunter  who live close by in Ayrshire.

Gregorie said: "We particularly like the flower design, because the thorn in them offsets the flower. Initially, we tried thorns but it looked like Alcatraz."

The couple believe the process has been worth it, to turn their crazy dream into a reality. "It has taken a long time, 15 years, to get to this stage," said Gregorie.

Just when they were ready to take their high-end product properly to the marketplace, lockdown happened.

Gregorie said, "it has been quite tricky, we are living in strange times, which hopefully we will get through."

The couple didn't rest on their laurels during lockdown, they created a viral social media campaign called #Passthesalt which saw gift samples of their product with a miniature of homemade sloe gin being sent to industry insiders to raise product awareness.

Gregorie believes lockdown saw a renewed interest in locally sourced food, with "everyone playing their part working together and all moving in the same direction.

"Here in our village, the community has come together, our little shop has been really doing the job: delivering, vegetables, shopping, and takeaway curry deliveries" and he hopes that continues versus the convenience of aimlessly wandering about a supermarket."

The couple are really hoping that everyone in Ayrshire can get behind and support their unique artisan salt venture as it grows.

Taste test

"Rolling sweetness but mellow, it tickles your tastebuds, just like it trickles down the thorns."

Blackthorn Salt, Saltpans Road, Ayr, KA8 8BZ

01292 292 029

Location:none
Catriona is a freelance writer based in the Scottish Borders, and a nominee for Food and Drink writer at this year's Scottish Press Awards.
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