The term describes a specific phenomenon observed during the combustion process in wood-burning stoves. It refers to the visual appearance of faint, bluish flames, particularly noticeable under specific conditions, resulting from the burning of gases released during wood pyrolysis. An example would be observing the fleeting color within the firebox just after adding seasoned hardwood.
The presence of this hue often signifies efficient and complete combustion. This indicates that the volatile organic compounds (VOCs) released from the wood are being fully oxidized, leading to less smoke and creosote formation. Historically, understanding these indicators of combustion efficiency was crucial for maximizing heat output and minimizing risks associated with chimney fires. This observation suggests a cleaner burn and better fuel economy.