Well, this is the first winter that I have burned wood 100% off of my own property..Its a mixture of predominatly soft maple and cherry with alittle red oak mixed in..In the past I ahve ordered wood that was predominatly hard maple, ash, red oak.. I must admit that I do not get the btu's or longer burn times with the soft maple etc...I knew that going in but figured I would just burn more wood which I have, I mean its basically free. THis past fall I have more red oak bucked up already for this coming season.. Imight look around and drop some hard maple if I can find it or simply order a cord of logs of hard mapole to mix in.