Buzz
For over a century, the cardinals have used colored smoke as a signal of their progress in selecting a new pope. Black smoke indicates no pope has been elected, while white smoke means a pope has been chosen.
The tradition began with light smoke produced by burning ballots and dry straw, and dark smoke generated by burning ballots and wet straw. However, the signals were not always clear, and at times the smoke confused those waiting outside. During the 1958 conclave, white smoke appeared after a vote, prompting cheers from the crowd and an announcement from Vatican Radio that a pope had been elected.
But moments later, the smoke turned dark. The straw added to the fire didn’t catch immediately and required some time to ignite properly.
In an effort to eliminate confusion, the cardinals and Vatican officials experimented with various methods to ensure the smoke colors and election results were unmistakable. In the 1960s, smoke bombs were used to create black smoke. While they made the color clear, they also filled the room with smoke, causing the cardinals to cough uncontrollably. Later, Italian army flares were tried, but although they produced a distinct color at first, the smoke quickly turned gray, leaving many confused.
In 2005, the Vatican embraced modern technology and introduced an 'auxiliary smoke-emitting device' that used chemical cartridges to produce distinct colored smoke for up to six minutes. The contents of the cartridges remained a mystery, with the Vatican only revealing that they were made from 'several different elements.'
Recently, the Vatican disclosed the details of their smoke production process. According to a press release from the Vatican, the smoke device includes a compartment where 'different coloured-smoke generating compounds can be mixed.' The color is determined using an electronic control panel, and the smoke lasts for several minutes as the ballots burn in the stove.
The black smoke is created using a blend of potassium perchlorate (a common oxidizer in colored fireworks), anthracene (a hydrocarbon found in coal tar), and sulfur. Meanwhile, the white smoke is made by mixing potassium chlorate (similar to potassium perchlorate, used in fireworks and smoke bombs), lactose (a sugar in cow's milk), and rosin (a resin from conifer trees).
