The unmistakable curved shape of its bottle has been part of Coca-Cola’s image since the original glass contour bottle was introduced throughout the United States in 1916. To this day people wonder where the design came from, and some odd theories about its origins have surfaced over the years, including one about its being modeled after a Victorian hooped dress.

(One popular misconception credits the bottle’s unique form to famed industrial designer Raymond Loewy. That one is easily dismissed as Loewy didn’t arrive in America until 1919, three years after what came to be called the “hobble skirt” bottle was in wide distribution. Loewy later designed products for Coca-Cola such as cans, coolers, and vending machines, which likely led to this misconception. He also called the Coke bottle “the most perfectly designed package in the world,” and it’s unlikely he’d have been that arrogant if he were describing his own design.)

None of the false theories is any more odd than what the Coca-Cola company itself claims as the correct origin, however.

Back in 1915, soda bottles were pretty much the same shape no matter which beverage they contained. What differentiated one unopened soda from another was its label. That was a workable system, except for one problem: paper labels slid off when the bottles they were affixed to became wet.

In those long-ago days, keeping soft drinks chilled was typically accomplished by leaving them in tubs of ice water. This led to confusion and frustration as customers blindly fished around in cold water for the brands they wanted. Finally, a light bulb went off over someone’s head: what if Coca-Cola’s bottle had an unusual shape? The days of brand confusion would be over, because a customer could easily pick out an ice-cold Coke by feel alone.

So much for the decision to shape the bottle differently; now on to where this particular shape came from. Though I grant this is a hard one to swallow, Coca-Cola swears it happened like this:

A heat wave shut down operations at the Root Glass Company of Terre Haute, Indiana, one of Coca-Cola’s bottle suppliers. As a result, there was free time to be frittered away on odd projects. Plant manager Alex Samuelson was puzzling over the Coke bottle design problem when he was struck by an inspiration. What if the bottle were made to resemble the shape of either a kola nut or a coca leaf, the two ingredients the flagship product had been named for?

He dispatched one of his employees (a fellow by the name of Clyde Edwards) off to the city library to look up information about those two items. A misunderstanding occurred, leading Edwards to the wrong page of the Encyclopedia Britannica. The sketches he returned with were turned into the bottle design we know and love so much today, but the vertical striations and curved, bulging middle bore no resemblance whatsoever to either the coca leaf or the kola nut. Instead, they were a darned good rendition of a cacao tree seed pod. Yes, cacao. As in chocolate.

While this story has been related in books, and with my own ears I’ve heard it told as gospel at both the Coca-Cola Museum in Las Vegas and its parent museum in Atlanta, it’s not the actual truth. Instead, the preceding account is a highly colored version of what actually occurred. (Mystique overshadows truth in other Coca-Cola origin tales, such as the company’s claim that the beverage was carbonated by accident.)

Instead, acutely aware of the need for a better container for its product, in 1915 Coca-Cola sponsored a design competition among its bottle suppliers. The contest listed only two requirements: the bottle had to be distinctive and had to fit existing equipment. While the Root Glass Company of Terre Haute’s plant manager Alex Samuelson and plant employee

Clyde Edwards were tangentially involved in the process that led to the design of what became the quintessential Coca-Cola bottle, the actual designer and the man who ultimately turned his own artistic concept into the prototype bottle was Earl R. Dean, the supervisor of the bottle molding room at that facility. Moreover, there was no “happy accident” of mistaking one page of the encyclopedia for another. Dean, inspired by Samuelson’s query about what made up Coca-Cola, posited that there might be a bottle design idea to be found in the look of either the coca plant or the kola nut (the two ingredients Coca-Cola is named for), and set out for the local library to unearth information about those two ingredients with Clyde Edwards in tow. (As the auditor at Root Glass, Edwards knew his way around the library and therefore was thought likely to be able to assist Dean in his search.)

There was no information to be found about either the coca leaf or the kola nut at the local library, which scotched that plan. However, a picture of a cacao pod in the Encyclopedia Britannica gave Dean a further jolt of inspiration: he realized that the striations on that rather odd-looking gourd-like thing might serve as the jumping-off point for a workable bottle design. He sketched a copy of the drawing, took it back to the plant, worked up a bottle design based upon it, presented it to C.J. Root (the plant’s owner), gained his approval, created a mold for the prototype bottle, and produced one. That bottle became the widely-recognized symbol of Coca-Cola.