 You're going to have to do some figuring out of how much sugar you've got in there and how liquid you actually want this because you may not want to burn off all the water. You may want to do something else. Probably, if I were using it for the sweetener, I'd go ahead and use a properly finished maple syrup, but that may not be what you're trying to do. That's where it gets tricky on this level of brewing.