It's bright orange, tastes like nothing else on a shelf, and for most of the last hundred years has done something almost no other soft drink on earth manages: outsold Coca-Cola in its home market.
From "Iron Brew" to Irn-Bru
The drink was launched in 1901 by Robert Barr in Falkirk, originally sold as "Iron Brew". The name changed to the phonetic "Irn-Bru" in 1946, largely because UK labelling law required drink names to accurately reflect their contents, and the drink wasn't actually brewed from iron - it just contains a small amount of ammonium ferric citrate, an iron compound, among its ingredients.
The secret recipe
- Known to very few people — A.G. Barr has never published the full recipe, and it's reportedly known in complete form to only a handful of people at any given time.
- Guarded like a corporate crown jewel — the formula is kept secure rather than patented, since a patent would require publishing the full ingredient list.
- The flavour itself defies easy description — most drinkers describe it as somewhere between bubblegum and citrus, which is part of why it's so hard to copy convincingly.
Outselling Coca-Cola on home turf
For most of the 20th century, Irn-Bru was the best-selling soft drink in Scotland, ahead of both Coke and Pepsi - a feat almost no other country's local soft drink brand has managed against Coca-Cola's global dominance. That performance is why it picked up the "Scotland's other national drink" nickname, sitting alongside whisky as a genuine symbol of Scottish identity rather than just a regional favourite.
The 2018 recipe change
When the UK's Soft Drinks Industry Levy came into force in April 2018, taxing drinks above a set sugar threshold, A.G. Barr reformulated Irn-Bru to roughly halve its sugar content rather than pass the tax on in price. The change prompted a genuine public backlash, with long-term fans stockpiling the original recipe and petitioning for it to be brought back - a reaction that says a lot about how attached people are to the exact taste of the original. Fans of bold, fizzy flavours might also want to browse the site's fizzy sweets, several of which chase a similarly hard-to-place tang.
Frequently asked questions
Why is Irn-Bru called Scotland's other national drink?
Irn-Bru earned the nickname "Scotland's other national drink" because it's one of the only soft drinks in the world to consistently outsell Coca-Cola in its home market, giving it a cultural status in Scotland usually reserved for whisky.
Is Irn-Bru's recipe really a secret?
Yes - A.G. Barr has kept the Irn-Bru recipe confidential for over a century, reportedly known in full to only a small number of people at any one time, with the formula held securely rather than published or patented.
Did Irn-Bru's recipe change?
Irn-Bru was reformulated in 2018, roughly halving its sugar content, after the UK introduced the Soft Drinks Industry Levy (the "sugar tax") - a change that prompted a significant public backlash from long-term fans of the original recipe.