A friend of mine gave me a Kenmore side by side he wasn't using so that I could do turn it into a fermentation chamber. I was looking into the ebay temp controllers and stumbled on this thread. I applied this technique. After a few days and some tweaking of the freezer thermostat, the freezer...
I did a simple all grain brew last sap season, replacing all the water with sap. I didn't notice any flavor contributions. You have to boil down a lot of sap to start getting any maple flavor. You might want to try a maple wine instead. http://scorpius.spaceports.com/~goodwine/maplewine.htm