During the shoulder season when I'm burning primarily softwoods (pine, hemlock, and poplar), I tend to have a lot of ash left in the bottom of the wood stove after the fire goes out. Now, I've switched over to hardwoods (red oak and white oak) for the winter season and have very little ash left in the bottom of the stove after the fire goes out. Does anyone on the forum understand why? I'm sure there has to be some scientific explanation.....