He succeeded in identifying the precise ingredients that give the drink its unique taste, after its trade recipe had remained a secret for more than 139 years.
Armstrong's experiments showed that more than 99% of Coca-Cola is made up of sugar, which is to be expected, as the product label states that one liter contains about 110 grams of sugar, 96 milligrams of caffeine, 0.64 grams of phosphoric acid, in addition to caramel coloring.
But the real challenge in recreating Coca-Cola at home lies in the remaining 1% of ingredients, which give the drink its distinctive flavor. Armstrong discovered that the secret lies in a blend of "natural flavors," including a mixture of essential oils such as lemon, lime, tea tree, cinnamon, nutmeg, orange, and coriander, as well as a natural pine-like flavoring called "Vincol."
This mixture is left to mature for 24 hours before being diluted with edible alcohol. Surprisingly, a very small quantity of these oils is enough to produce thousands of liters of Coca-Cola.
Coca leaves play a key role in Coca-Cola's distinctive flavor. These leaves, grown in South America, are from the same plant as cocaine, but Coca-Cola uses a cocaine-free extract. In the United States, Stepan Inc. is the only entity authorized to import coca leaves and does not sell them to the public.
Coca leaves contain natural compounds called tannins, which are responsible for the astringent or bitter sensation in the mouth and are also found in tea, coffee, and wine. These compounds are non-volatile, meaning they often don't show up in conventional chemical analysis, which explains the difficulty in detecting them. To solve this problem, Armstrong used commercially derived tannins to mimic the taste of authentic coca leaves.
Using mass spectrometry, Armstrong analyzed and precisely separated the chemical components of the original beverage. He was then able to create a chemically identical version, without the need for coca leaves.
In the final version, tannins and water are mixed with caffeine, sugar, vanilla extract, phosphoric acid, caramel coloring, vinegar, and glycerin to thicken the consistency. A concentrated blend of diluted essential oils is then added, and the mixture is combined with carbonated water (sparkling water containing carbon dioxide bubbles) to give the drink its characteristic fizzy texture.
Armstrong asserts that the result is almost identical to the original drink, noting that the cost of preparing liters of diluted Coca-Cola is only a few cents, and all the ingredients are legal and readily available online. However, he advises using protective equipment when handling the concentrated chemicals.
