I did a maple sap cream ale last year using the sap as first sparge water without treatment. Some could taste a subtle maple flavor, I could smell maple but not taste it. At 40:1 getting maple flavor from sap is tough, but it is good marketing, espcially in your neck of the woods. On the next batch I used Grade A light amber, not my personal favorite for consumption, but it kept the maple flavor throttled back. It turned out well and had a good maple background.
If the sap is free or really cheap it's worth the effort.
I spent my summers as a kid in Westport, NY on Champlain. Coming up again this summer and planning on stopping by.
Blue Lab Brewing Co.