Over time your schlag may change in shape or appearance. Why is that?
Let's talk about the awkward topic of shrinkage.
In technical terms: As wood dries and the water cells collapse, the circumference and diameter shrink slightly. This causes tension in the log and to relieve it, the log cracks at the edge. The bark is already dry so as shrinkage happens, the wood pulls away from the bark causing it to fall off.
In Minneschlagen terms: Your log (schlag) may crack and the bark will likely fall off, not only due to shrinkage but because you are repeatedly hitting the schlag with a hammer.
Adds character, right!? What won't change is the performance of the game - it will still be a huge HIT!