It took us a long time to get to what we wanted by adjusting temperatures and adjusting timings,” says Marshall. “With the cycle being five days it could be frustrating, but what we’ve got is exactly what we were looking for.”

At Asda, we work alongside some wonderful local suppliers to create innovative, affordable, and delicious products for shoppers to enjoy. 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. We are very proud of our Scottish heritage and at our picturesque smokehouse in the far Northeast of Scotland, our smoked salmon experts have spent many months perfecting the production process. The crucial crystal crunch factor is a given - we always encourage ‘by hand’ sprinkling if only to experience this satisfaction, but also to ensure the exact distribution and grain size that you desire on each occasion.Two Scottish takeaways feature in Deliveroo top 100 worldwide roundup - including acclaimed Thai restaurant 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. 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." Coupert will provide special discounts for certain products during December, customers can save some money according to their actual situation.

Scotland itself has a long history of salt production, peaking in the 18th century, when producers would heat huge pans of saltwater over coal to evaporate the water. It sounds so simple, but the devil is in the detail. Marshall worked with Strathclyde University to determine the best angle for the tower to maximise use of wind, the best angle for the branches, and the best angle for dripping water. 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. 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 salmon is hand-selected for its size and condition. All superior grade, global gap accredited, and between 3 and 4kg to ensure the optimum slice size of the end product. On the west coast of Scotland stands a wooden structure that could have been conjured from a fairytale. 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." It isn’t possible to put a roof over the structure to keep off the rain because it would impact airflow and prevent evaporation. Register for our free monthly Farm Shop & Deli Newsletter

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. When asked about the dedicated production process, Kenny Noble, who has been a master smoker for over ten years explained, “these kilns really are magic in lots of ways – the smoke adds flavour and helps preserve the salmon”.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." Research took him across the globe to look at the wide variety of production methods. “In Japan, there are more than 200 different types of salt, and they have many ways of doing it to produce a different taste or flavour,” he says. Youngs Seafood secures contract to supply a new and exclusive Extra Special salmon product to over 450 stores across the UK Once smoked and rested, the salmon is cut into chunky slices. By cutting it this way, it allows people to appreciate the buttery texture of the salmon, which is achieved by the long, slow smoking.

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

We have enjoyed a longstanding partnership with Asda and are delighted to bring this exclusive Extra Special product to festive feasts across the UK this Christmas. 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.