Diet Coke loyalists made it nearly impossible to fix the struggling brand — here's why Coca-Cola is making massive changes anyway

Diet Coke's recipe will remain unchanged as Coca-Cola
While Diet Coke sales have declined in recent years, Coca-Cola says it won't change the flavor that is "loved by millions of fans."
Instead, Coca-Cola is revamping Diet Coke's design, rolling out a new marketing campaign and adding four new flavors.

Coca-Cola is making massive changes to Diet Coke — but it isn't tinkering with the iconic beverage's recipe.

On Wednesday, Coca-Cola announced it is rolling out modernized Diet Coke packaging and a new ad campaign as well as quirky new flavors such as Feisty Cherry and Zesty Blood Orange.

But the beverage giant was quick to say it was not changing the recipe for the original Diet Coke.

The second line of Coca-Cola's post on the brand revamp reads: "And no, the one-and-only Diet Coke is not being reformulated. It continues to be available nationwide."

There's a reason why the beverage company is so quick to reassure customers that Diet Coke's recipe will remain unchanged. While sales have been declining for years, the drink still has a dedicated fan base — one that would be quick to revolt if anything changed about Diet Coke.

"I don't think we're likely to change Diet Coke," CEO James Quincey said in a call with reporters in October. "It has a large following."

It has been clear that Coca-Cola needed to address its Diet Coke problem for a long time. According to the company, it began working on developing new Diet Coke flavors two years ago.

For the last few years, Diet Coke has been the weakest link in the company's cola lineup. In October, Coca-Cola reported the brand's sales by volume declined in the mid-single digits last quarter. Industry publication Beverage Digest reported Diet Coke US sales by the dollar dropped 1.9% in 2016.

Despite the decline, Coca-Cola determined that the risk of alienating loyal customers with a new recipe was too great. Adding new flavors, along with a more modern design and ad campaign, is an attempt to fix the brand without incurring the wrath of loyalists.

Coca-Cola "has heard fans loud and clear on one thing: the same great Diet Coke taste loved by millions of fans is not changing," the company said in its post on the brand revamp.