Spalting lumber is a mixture of art, science, and a good game of craps. The art is the product produced of the right species of fungus adequately attacks and evenly spreads through a piece of wood. Additionally, insects often carry the fungus, so spalted lumber is often wormy.
The science is the species of fungus, the moisture content of the wood, the age of the wood reducing the concentration of natural antifungal agents in the wood and the temperature the fungus is maintained at during its growth.
The game is knowing when to open the log and end the process. Too early and you have light spalting that is reminiscent of stain, and too late and you have a soft mush that won’t even make good firewood.
We use a variety of species of fungus and techniques to spalt wood to the right degree and on occasion we get lucky.