All kinds of nasty in thick bark wood . Thin bark like apple , no problem for me . Oak or hickory ,,, get rid of the bark . You see the above post ? " CLEAN WOOD "
May I suggest, you build a bed of charcoal and add BARK ONLY and smoke some meat.... Then do the exact same only use CLEAN WOOD with NO bark...
That way you can determine the taste you are looking for....
Chop