I find I have a much more consistent boil with hardwood. I almost always start with pine, simply because almost all of my pines are dead due to the pine bore. But, I will burn anything that does not move. Ash has been working very well, and there is so much of it available. I have a deep ash pit in the evaporator. That, and since I added forced air, I do not have an excessive buildup of coals. I also have a good stockpile of wood this year. Last year it was: make syrup, or heat the house.