A simple 1x1 piece of red oak 12" long was balanced on a blade and it did so very near the center. It then went upright into a tray of water 1" deep. At one hour the balance point had changed considerably. At 10 hours the balance point stopped moving toward the wet end. At 12 hours the balance point was moving back toward the previously dry end. Stabilization took 16 hours and the final balance point was just over 3/4" from the center.
Feel free to repeat the experiment as it takes next to nothing and very little time.