Its the foam that's causing trouble. Last batch , we got about twice as much foam as syrup. After three days in a 100 degree oven, the foam was reduced to about a third, but I hate to throw away that much product. (Maybe we could market it as "brown marshmallow cream"). Next time, (tomorrow) we're gonna fill the pan fuller and maybe it won't get away from us. I cut the heat shield down about 6" to get the fire on the bottom only. Might help.
Ended up pretty thick -about like pine tar; but O.K. for heavy syrup. Two pans would be better. We're thinking maybe to quit half way, set it aside and finish cooking it later in smaller batches.
Another question is about the variety of cane. As many types as there are, they ought to result in different syrups. And probably different processing methods; with a different bugbear for each!
At least it makes good cattle feed; once they figure out what it is. So far the cows are the most consistent part of the whole game.