Pope Selection: What Black And White Smoke Mean At The Vatican Conclave

As the world watches St. Peter’s Square, a simple chimney atop the Sistine Chapel becomes the centre of attention during a papal conclave. On Wednesday, May 7, a plume of black smoke emerged from the chimney, signalling that the cardinals had not yet chosen a successor to Pope Francis in the first round of voting.

The ritual of using smoke signals from the chapel’s chimney is how the Vatican communicates the outcome of each ballot to the public. If white smoke appears, a new pope has been elected. If the smoke is black, it indicates no candidate has secured the necessary two-thirds majority.

Smoke signals have long been used across cultures to warn of danger, summon gatherings or convey messages. Indigenous communities, in particular, have developed intricate systems to communicate specific signals, reports CBC News.

The Vatican’s tradition of using smoke to announce the outcome of a papal election can be traced back to the 19th century, historians say. According to Frederic J Baumgartner in his 2003 book Behind Locked Doors: A History of the Papal Elections, the earliest documented use of smoke as a papal signal dates to 1823, The New York Times reported.

The smoke seen rising from the Sistine Chapel chimney is produced by burning the paper ballots, along with any notes the cardinals may have made during the voting process. These papers are fed into a cast-iron stove inside the chapel after each voting session. On the first day, one round of voting takes place. Thereafter, four rounds are held daily — two in the morning and two in the afternoon. Unless a new pope is elected, the ballots are burned after every two rounds.

Black smoke billowing from the chimney signals that no candidate has yet secured the required majority, while white smoke proclaims to the world’s 1.4 billion Catholics that a new pope has been chosen.

Initially, wet straw was added to the burning papers to produce white smoke, while dry straw yielded black. But this traditional method sometimes led to confusion, with smoke appearing grey or unclear. One example occurred in 1958 when an ambiguous plume caused uncertainty among onlookers.

By the 1978 conclave that elected John Paul I, the Vatican introduced chemical cartridges to ensure the smoke’s colour was distinct. The same system was used later that year when John Paul II was chosen following his predecessor’s sudden passing after just 33 days in office.

In the most recent conclaves, this black smoke is created by mixing potassium perchlorate, anthracene, and sulphur. When a new pope is chosen, the process changes — a different set of chemicals, including potassium chlorate, lactose and chloroform resin, are added to ensure the smoke billows white.

Beyond the smoke, another tradition reinforces the announcement. Once the white smoke rises, bells at St. Peter’s Basilica begin to ring, soon echoed by other churches across Rome, making the message clear both visually and audibly.