A true Texas original is celebrating a major milestone.
Dr. Pepper is now the oldest major soft drink in America.
According to the U.S. Patent Office a Waco drugstore served the first glass on December 1st, 1885.
Fast forward 125 years and Dr. Pepper sells more than 530 million cases worldwide.
Reporter Kevin Cokely recently took a VIP tour of the company's headquarters and top secret flavor lab.
Dr. Dave Thomas, the senior vice president for research and development at Dr. Pepper-Snapple led the tour.
He's one of only three people in the entire world who know the super-secret formula for the unique blend of 23 flavors in Dr. Pepper.
The 125 year old formula is so secret even the vault its locked away in is secret.
Still, Thomas was willing to share some of the other secrets behind Dr. Pepper's success.
Real doctors, including Dr. Thomas, work at Dr. Pepper.
About 75 people work at the company's state of the art R & D lab in Plano, many of them scientists with PhDs and other advanced degrees.
Together they work on improving the more than 50 products already in the Dr. Pepper-Snapple group
and create new ones.
Experts called "flavorists" come up any new drinks, like the most recent Dr. Pepper Cherry.
The flavors technology lab is filled with samples of more than three thousand flavors, including the 23 in Dr. Pepper.
Every new product starts in a chemistry lab where scientists put the formulas together.
Some formulas are less secret than others.
Sometimes people may be a little blue tasting Dr. Pepper products.
Blue lights in the sensory lab mean taste testers can't tell a new drink's true color.
"Sometimes you may have subtle color differences, and you want to take that variable out of the equation," Thomas explains. "So by having a blue light, it just mutes everything so that colors not a variable."
There is one thing they admit is not in Dr. Pepper: Anything to do with prunes.