EWTN Catholic Q&A
White smoke & Black smoke
Question from Lily Monahan on 04-19-2005:

I am four years old and I wanted to know, how do they make the black and white smoke? Thank you and God Bless you!

Answer by Colin B. Donovan, STL on 04-26-2005:

Good question, Lily.

Just by burning the paper ballots of the Cardinals they get the black smoke. To get the white smoke they add a chemical to the burning ballots.

God bless.