Coke, Twinkies, others say their “secret” recipes haven’t changed in a century, but some have

ATLANTA – Coca-Cola keeps the recipe for its 127-year-old soda inside a steel vault that’s bathed in red security lights. Cameras monitor the area to make sure the formula stays a secret.

But in a sign that the surveillance is as much about theatre as reality, the images that pop up on video screens are of smiling tourists waving at themselves.

The ability to push a narrative about a product’s origins and fuel a sense of nostalgia can help drive billions of dollars in sales. It’s why companies play up the notion that their recipes are sacred, unchanging documents that need to be closely guarded.

As it turns out, some products have changed, while others may not have. Either way, companies try to make people believe their recipes have remained the same.