yeah the sapwood on oak starts to decay and hold moisture. The mushrooms are just finding the food and moisture it needs to thrive. Even well covered, the high humidity in the area can be enough for the shrooms. I've never found them to be a problem in the stove. They seem to burn well enough, although their BTU content is probably close to nil.
X2 with the heartwood. I have a couple felled white oaks from May to CSS yet and the heartwood will be split out and stacked separate. I did that with a couple huge pin oaks this year. Couple cord of heartwood. Too bad you didnt have any more oak laying around!
After this terribly wet summer thats also how most of my oak looks its also still hovering around 22% and been css for 3 years.
Snapped a couple pics of one of my oak stacks yesterday. White oak in back, red oak front. 3 years CSS Plastic had a hole. Big mushroom bloom
