In article , David W.E. Roberts
writes
Heh. Getting a gallon of the stuff might be a challenge.

Only tried this once, years ago.

I managed to get about 1/2 gallon from one large birch tree (only one we
had).

Made a very nice wine, but a lot of trouble collecting the sap.

The tree survied with no obvious ill affects.

Walnut tree sap can be used in much the same way. In springtime I drill
a hole in the bark large enough to take a siphon tube and collect the
sap in a demi-john. Our very large walnut trees provide a gallon of sap
in a few days. The hole heals over during the following summer.
--
Alan & Joan Gould - North Lincs.