When a pope dies or resigns, centuries-old traditions and rituals unfold as the Roman Catholic Church begins the process of electing a new Bishop of Rome. These traditions include the use of smoke to announce the selection.

The dean of the Sacred College of Cardinals calls all cardinals under age 80 to gather in the Vatican for a private meeting, called a conclave, to select a new pope from their midst. The cardinals who are eligible to vote use paper ballots and later burn them to communicate with the outside world.

Cardinals are appointed by the pope for life, but they are no longer eligible to vote after age 80. As of February 2025, 125 cardinals were eligible to vote and 14 were not.

Deliberations and Voting at the Vatican

The conclave is highly secret. Once the cardinals arrive at the Vatican for the meeting, they cannot leave, nor can they talk with anyone outside the proceedings. They begin with a mass in St. Peter's Basilica and then enter the Sistine Chapel to start their deliberations and voting. No recording devices are allowed in the chapel, and technicians check for hidden microphones and cameras before balloting begins.

Paper ballots are distributed, and each cardinal secretly writes a candidate's name on his paper. With the folded ballot in hand, each cardinal approaches an altar in order of seniority and places his ballot into a chalice.

Although each cardinal votes in secret, ballots are opened and counted in front of the group. A cardinal must have a two-thirds majority to become a pope. If no one reaches that number after a vote, the process repeats once on the first day and four times on succeeding days until a new pope is selected.

Ballots are taken to a furnace or stove and burned after several rounds of voting. Chemicals are added to the paper to turn the smoke black or white. Black smoke indicates the cardinals have not elected a pope and white means they have.

There have been problems in the past when the smoke coming out of the chimney was an inconclusive gray. Consequently, the Vatican has taken steps to remedy the situation. The solution has been to construct what is essentially a smoke bomb and to add chemicals to the smoke. The system now in use has been refined and tested to help ensure the best possible outcome.

Practical and Symbolic Reasons For Using Smoke

The Vatican has used smoke for centuries to signal the election of a new pope. This tradition has continued despite the advent of radio and television in the 20th century and digital communications in the 21st. There are several practical and symbolic reasons for using smoke to communicate important news about the election of a new pope:

1. The smoke's color is a way to instantly tell the world's 1.2 billion Catholics whether a new pope has been chosen. Black smoke may be a disappointment, but the release of white smoke is a highly anticipated signal that heralds a new Bishop of Rome and a new era in the Roman Catholic Church. With television cameras aimed at the chimney on top of the Sistine Chapel, the world is watching. Consequently, the Vatican needs to release smoke whose color is unmistakable.
2. Smoke also has several symbolic meanings for Catholics. It represents divine guidance in the selection of the new pope and offers Catholics around the world an opportunity to connect with centuries-old traditions visually. In recent times, black smoke has come to signify reflection and patience. White smoke stands for purity, unity, divine choice, guidance and clarity, and the beginning of a new era led by a new pope.
3. The appearance of smoke was also significant in the Old Testament because it indicated God's presence and intervention. One example was when smoke rose from the burning bush on Mount Sinai.
4. Before the advent of modern communications, smoke allowed Catholics gathered at the Vatican to see and understand the results regardless of their language or proximity to St. Peter's Basilica.
5. Additionally, the church began using smoke in its early history as a security measure. The cardinals locked themselves away from the outside world to deliberate and vote in absolute secrecy, as they do today. By using smoke to announce the results, they did not have to unlock the door where their meetings took place, which might have introduced security breaches to their proceedings.

Black smoke also heightened the suspense of conclaves held in early church history. The repeated release of black smoke added a layer of mystery to the Catholic Church's internal decision-making processes, as it continues to do today. The release of long-awaited white smoke, on the other hand, creates feelings of relief and excitement among Catholics.

Earlier Problems With the Smoke

At previous conclaves, the Vatican burned damp straw with the cardinals' ballots and notes to produce black smoke. To obtain white smoke, they burned their ballots and notes without straw. Most smoke contains tiny particles that result from incomplete burning, and its color depends on the content of those particles. Black smoke generally consists of carbon particles, while white smoke consists of water and fuel vapor or mineral ash.

But the Vatican has sometimes had problems with black smoke. Occasionally, the smoke appeared gray and wasn't definitive, leaving the waiting crowds unsure whether they had a new pope.

To eliminate the confusion, the Vatican remedied the situation in 2005 by introducing chemical compounds to color the smoke. Black smoke now comes from a mixture of potassium perchlorate, anthracene (a good additive because it produces large black particles) and sulfur. For white smoke, the chemicals are potassium chlorate, lactose and rosin.

Given this new process, the Vatican uses two stoves to produce the smoke. The cardinals burn their ballots and notes in one stove while the other stove burns the appropriate chemical additives. The two streams of smoke then come together in a single chimney.

In early times, the Vatican rang bells or fired cannons to announce the selection of a new pope. It began using black or white smoke in the early 20th century and now announces the election of a new pope with smoke and ringing the bells.

The use of smoke to announce the election of a new pope is a centuries-old tradition that is both practical and symbolic.

While modern technology could easily replace this method, the Vatican continues to uphold this deeply ingrained ritual because of its historical significance, universal visibility, and the anticipation it creates among Catholics worldwide.

The sight of white smoke rising from the Sistine Chapel signals not just the selection of a new leader but also the beginning of a new chapter in the Catholic Church. The tradition remains a powerful and unifying moment for the global Catholic community.