LONDON — It’s orange, fizzy and tastes like liquid bubble gum.

And while whisky is Scotland’s national drink to the world, to many locals, Irn Bru is a close second.

The company that makes Irn Bru says it will reduce the amount of sugar in its iconic drink this month, a change that has caused an uproar among its large fan base. The change in recipe, widely attributed to a new soda tax that comes into force in Britain this year, has also led to reports of panic buying in Scottish supermarkets.

“It’s one of our symbols of being unique and different in the way we feel about ourselves,” said Stephen M. Blythe, a technology lawyer in Glasgow.

After he saw an announcement on the company’s website about the change in his favorite drink, he set up a Facebook page to try to stop the recipe alteration. He has since joined forces with another man who began a Change.org petition for the cause.