How do they create white and black smoke for the Papal Conclave?

As the world begins to look ahead to the upcoming conclave following the death of Pope Francis, Patrick Madrid took a moment on The Patrick Madrid Show to demystify one of the most iconic traditions in the papal election: the white and black smoke signals from the Sistine Chapel.

Madrid explained that the smoke—white for a successful election, black for an inconclusive vote—is not merely a symbol but the result of careful chemical preparation. Since 2005, the Vatican has used a precise combination of compounds to ensure clarity. For white smoke, the mixture includes potassium chlorate, lactose (a sugar compound), and rosin, a resin derived from pine trees. When burned together, these create a clean white plume that unmistakably announces a new pope has accepted his election.

Conversely, black smoke is produced using potassium perchlorate, anthracene (a hydrocarbon), and sulfur—a blend that yields thick, dark smoke to indicate no decision has been reached.

Before modern chemistry, the process was more rudimentary—and more confusing. Wet straw was added to the burning ballots to produce darker smoke, but this often resulted in murky gray emissions, leaving spectators uncertain. To avoid ambiguity, the Vatican adopted chemical compounds during the 2005 conclave that elected Pope Benedict XVI.

Madrid also described the care with which the ballots are handled: each one is counted, threaded with a needle to ensure none are missing or added, and then ceremonially burned.

As the Church prepares for another conclave in the coming weeks, Catholics around the world will once again turn their eyes to the small chimney above the Sistine Chapel—awaiting the moment when white smoke signals that the successor to St. Peter has been chosen.

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At this pivotal moment in our Church history, don’t just observe the conclave – understand it, experience it, and pray through it with Relevant Radio at Conclave2025.com.