Decoding the Vatican’s Smoke Signals: The Tradition Behind Announcing a New Pope

When the cardinals convene behind closed doors in the Sistine Chapel to begin selecting the next pope, the world’s attention shifts to a chimney rising above the chapel’s roof. This chimney emits a plume of smoke that communicates the progress of the election: white smoke signals that a new pope has been elected, while black smoke indicates that the voting remains inconclusive.

This signaling method dates back to the 19th century, originating when papal conclaves were held at the Quirinale Palace, the former papal residence in Rome that now serves as the Italian president’s official home.

Historical research into the use of smoke as a communication tool during papal elections points to 1823 as the earliest documented instance. While cardinals had previously burned their ballots during conclaves, there was no clear record that the resulting smoke was intended to inform the public about the election’s outcome.

The smoke is produced by burning the ballots and any notes the cardinals have made, all placed into a cast-iron stove after each voting session. On the first day, a single round of voting takes place; thereafter, up to four rounds occur daily, split evenly between morning and afternoon sessions. Ballots are burned following every two rounds of voting, except when a pope is successfully chosen.

Until recent decades, wet straw was added to the stove to generate the white smoke that signals an election result. However, this method was not always consistent.

Notably, during the 1958 conclave, white smoke appeared twice on the second day of voting, creating confusion as no pope had yet been elected. This incident highlighted the challenges of relying solely on smoke color for public communication.