An out-of-date Irn-Bru bottle is being sold on eBay for £250 – but that isn’t as bizarre as it sounds. When the recipe was changed in 2018 in response to the sugar tax, the drink’s maker, AG Barr, confidently predicted that most people wouldn’t notice the difference. This proved to be a tragic miscalculation. A furious campaign (“Hands off our Irn-Bru”) was launched to protest against the decision, with a change.org petition getting just under 54,000 signatures.

Things reached such a frenzied state that 2,000 people signed up to a plan to break into the factory and steal the original recipe (Scotland’s answer to the storming of the Bastille). Disappointingly, this scheme never came to fruition. But the people of Scotland spoke with their wallets – AG Barr announced that its profits this year have plummeted by 20%.

It is widely agreed that the new recipe just doesn’t hit the same spot as the original. While I don’t hate the new version with quite the same venom as many of my countrymen, I would say it lacks a certain je ne sais quoi (except we know exactly what it lacks: about four teaspoons of sugar per can). After the sugar tax came into force, Scotland was plunged into the murky atmosphere of prohibition-era Chicago, haunted by rumours of corner shops where bootleggers still sold the original version under the counter. Obviously, this couldn’t last. The stockpile was always going to run dry sooner rather than later. The tragic result of all this is that now, in an act of desperation, some poor soul has no choice but to pay £250 for an out-of-date bottle.

None of this is particularly surprising when you consider the influence Irn-Bru exerts over the nation’s psyche. As Ryan Allen, the architect of the “Hands off” campaign, wrote in an emotionally charged appeal: “[Irn-Bru] is a national treasure in Scotland and really is part of our culture.” As well as the drink itself, Irn-Bru adverts are a much-loved institution, which express a particularly Scottish brand of ribald cruelty. My favourite is a festive spoof of The Snowman, in which the titular creature experiences such an intense craving for the drink that he allows a small boy to plummet to his death.

A strange mythology surrounds the company, too, that claims there are only three people alive who know the recipe and they are not allowed to travel on the same plane together. I had long assumed this was an urban myth, but it’s true (possibly not the plane bit). Although retired, the one-time head of Irn-Bru Robin Barr, still personally mixes the ingredients once a month in a sealed room, and then adds them to a giant vat.

Scotland is often said to be one of the only countries in the world, along with the likes of Cuba and North Korea, where Coca-Cola is not the most popular soft drink. Pathetically, this makes me feel a sliver of patriotic pride. I imagine the Coca-Cola executives clenching their fists in rage at plucky, defiant little Scotland foiling their plans once more. What better to way to cock a snook at the forces of global capitalism than by glugging a carbonated beverage that tastes only of rust and sugar? Whether Irn-Bru’s status as an unwavering symbol of Scottish identity can survive being made slightly healthier remains to be seen.