Carbonation and Coca-Cola

“What is the difference?” I asked the person across from me after they tasted the flat Coca Cola and the carbonated Coca-Cola. While it took them a while to get to their answers, they all followed the lines of “The flat one tastes duller and sweeter, and the bubbly one hits all around your mouth.”
At our Science Speakeasy Event, I presented a classic name brand: Coca-Cola alongside Robert Kriegel. With my knowledge of carbonation, I believed I had it all thought out, however during this event, I learned as much as I was taught. I do wish I could provide the recipe to Coca-Cola’s iconic taste for more insight, however, most are aware that the recipe is one of the biggest secrets known to man. On their website, it lists their ingredients as carbonated water, high fructose corn syrup, caramel color, phosphoric acid, natural flavors, and caffeine. While the corn syrup, caramel color, flavors, and caffeine make up a large part of what makes coca-cola iconic. I would like to focus on the process of carbonation and why phosphoric acid is involved.

The process of Carbonation seemed quite simple on the surface, but there was so much more to explain it. I learned from Robert that carbonation was made possible due to the high rates of solubility in carbon and that to carbonate a beverage you had to get specifics correct on the matters or temperature, pressure, and particle size. While you can dissolve other gasses in water, Carbon Dioxide is the best.
Carbon Dioxide also adds a bit of acidity, lowering the Ph Levels of the soda which gives it that tangy taste when carbonated. Also, it is part of the reason flat Coke tastes so sweet. But the main contributor to the acidity was through phosphoric acidity in the soda. The all-around your throat feeling was due to the sensation of the carbonated bubbles popping and exploding the flavored liquid all over your mouth.
However, with all of this fun science, Kriegel informed me that the CO2 concentration increases in the environment due to fossil fuel burning is increasing the carbon levels in the ocean causing it to have a small amount of carbonation. He warned me that if the carbon levels continue to increase it would cause harm to animals living in the water.

Chandrashekar, J., Yarmolinsky, D., Buchholtz, L. von, Oka, Y., Sly, W., Ryba, N. J. P., & Zuker, C. S. (2009, October 16). The Taste of Carbonation. Retrieved from
The Editors of Encyclopaedia Britannica. (2020, February 20). Carbon dioxide. Retrieved from