What is a flare-up?

A flare-up resembles a back draft, in the sense that there is insufficient oxygen for burning all the fuel. Flare-ups can be a little more dangerous but in general are manageable. A flare-up is the result of not just the oxygen-starved charcoal but also the fat dripping from a piece of meat or fish getting insufficient oxygen. You can predict a flare-up when heavy smoke with the smell of candle wax is billowing from the chimney. This indicates that the incomplete combustion of fats is taking place. Then these burned fats hover inside the dome in the form of greasy smoke (containing unhealthy PAHs). Now you have to be careful. If you open the lid, the fat will ignite, but since there isn’t heavy pressure, the flame will be yellow instead of blue. This can burn longer than a blue back draft.