HispanicBusiness

There is a high-tech aspect to the centuries-old Vatican tradition of using black smoke to signal that conclave voting has been inconclusive and white smoke to announce the election of a new pope.

Smoke comes from the burning of ballot papers in a special stove installed in the Sistine Chapel. The smoke signals, which usually last several minutes, are controlled electronically and are aided by a backup fan.

To make them black, a chemical compound made of potassium perchlorate, anthracene, and sulphur is added to the mix. White smoke derives from a mixture of potassium chlorate, lactose, and rosin - a natural amber resin obtained from conifers.

Until 2005, white smoke was created by using wet straw, while black smoke was made from smoke black or pitch.

It is not always easy to distinguish the signals, as sometimes the smoke appears grey, rather than white or black. Father Federico Lombardi, the Vatican's spokesman, quipped that "a bit of suspense" was part of the process.

"It makes it more interesting than if everything ran like clockwork," he said.