Bottles of Coca-Cola in a supermarket in Arizona, USA,
Bottles of Coca-Cola in a supermarket in Arizona, USA, October 20, 2009. REUTERS

Ira Glass and his crew at This American Life did some digging and discovered what they believe to be the original recipe of Coca Cola.

The latest weekend edition of the weekly radio show produced by Chicago Public Radio revealed the soft drink's recipe - which is guarded in a massive vault in the Coke's (NYSE: KO) corporate headquarters in George. The recipe dates back to 1886.

The most important part of the formula is the 7X, considered the backbone of the drink, which includes orange oil, alcohol, nutmeg oil, lemon oil, coriander, neroli and cinnamon.

This American Life actually published two version of the confidential drink. One recipe was taken from a photograph in an Atlanta Journal-Constitution article from 1979 and the other from a 1992 book about the cola industry, that purports to be the original recipe written by the 19th century chemist who created Coca-Cola.

The members of the radio show did a taste test and were unable to differentiate between their blend and the actual soft drink.

Here is the formula as it was revealed on the show.

Coca Cola Recipe From This American Life

Fluid extract of Coca: 3 drams USP

Citric Acid: 3 oz

Caffeine: 1 oz

Sugar: 30 (unclear quantity)

Water: 2.3 gal

Lime juice: 2 pints, 1 quart

Vanilla: 1 oz

Caramel: 1.5 ox or more for color

The secret 7X flavor (use 2 oz of flavor to 5 gals syrup):

Alcohol: 8 ox

Orange oil: 20 drops

Lemon oil: 30 drops

Nutmeg oil: 10 drops

Coriander: 5 drops

Neroli: 10 drops

Cinnamon: 10 drops

You can listen to the broadcast at www.thisamericanlife.org.