Secrets Unleashed

The Science Behind the Explosion

Magnified Image of Mentos Surface Believe it or not, the main reason for the Diet Coke and Mentos explosion is due to the mint candy's rough surface. According to New Scientist, the rough, dimply surface of Mentos encourage bubble growth because they effeciently disrupt the polar attractons between water molecules, creating bubble growth sites.

Diet Coke is the best combination with Mentos because research has found that the surface tension in water containing the sweetner aspartame is lower than the surface tension found in sugary water, explaining why Diet Coke creates a more extravagant fountain than regular Coke.

The last two contributing factors to the dramatic geysers are the Mentos density and coating. First, when the Mentos are dropped into the two-liter bottle, they sink rapidly creating bubbles that formulate further bubbles as they rise. Then its gum arabic coating helps reduce surface tension in the Diet Coke.