I did an experiment of sorts last year processing red oak that had been down on the ground in the woods for about 5 years. Punky sapwood, mushroom farm, bark falling off or gone completely. I cut it short, split it relatively thin and kept it top covered. Long story short, it went from very wet to under or just at 20% in about 6-7 months. I just burned the last of it this past weekend. Take all that at face value.