Expert: Chris Manley - 8/28/2008

Question
Hi Chris,
I have heard that if mentos(the chocolate) mixes with cold drinks like coke or Pepsi- it forms deadly poison, is it true? Is it harmful if I eat mentos after drinking coke or Pepsi?


Answer
The two do not form a poison, the CO2 in the soda rapidly forms bubbles on the surface of the candy.  Similar to what happens on the surface of a glass when you pour a soda into it, only this happens much more quickly.  

This reaction will not happen with a piece of candy that has already been eaten (unless you swallow it whole and then drink a can of soda quickly) because the properties that cause this reaction on the surface of the candy are changed when you eat it.