Ken, no I never tapped white birch before. Always wanted to try, but a couple years ago when my son bought the place, he trimmed the birches
a lot and they bled sap for weeks. So I would assume like maples, they should be trimmed in late summer or early fall. Still above freezing here tonight at 11PM, could freeze up by morning and get the maple sap running
again, there I go dreaming again.