leaf stained sap

[hillbillybee]

I've got a couple pails that leaves fell in and stained. If I boil will it give my syrup an off flavour?

[Run Forest Run!]

I can't imagine that it will, especially if they only represent a small percentage of the pails that you've got. I'm not sure how many pails you are collecting from this year. Why not taste a bit of the sap and see if there is an offensive off-flavour that you can detect. If not, toss it in the pan and boil it. I experimented once with a bucket of sap that had some tree-stained rain water in it. It tasted just fine once mixed in with everything else.