Here it is, right off Jack Kellers website.
MAPLE SAP WINE
* 1 gallon maple sap
* up to 2½ lbs granulated sugar
* 1 large or 2 small lemons
* 12-15 cloves
* 1/8 tsp tannin
* 1 tsp yeast nutrient
* 1 pkt Reisling wine yeast
First measure the specific gravity of the sap with a hydrometer to determine how much sugar to add to achieve a starting specific gravity of 1.085-1.090. Different saps will contain different amounts of natural sugar, and even the sap from the same tree will differ from year to year. In an enamel- or teflon-coated pot, stir the required amount of sugar into the maple sap and bring to a low boil for 15 minutes, stirring until the sugar is dissolved. In a separate pan, combine a cup of the sap with the cloves and zest of the lemon(s) and simmer for 10 minutes. Strain the latter into a primary and add the boiled sap, juice from the lemon(s) and yeast nutrient. When cooled to 75° F., add the activated yeast. Cover the primary and stir daily for 8-10 days. Transfer to a secondary and fit airlock. Ferment to dryness (6-8 weeks), rack into a sanitized secondary, refit the airlock and bulk age 12 months, checking airlock from time to time to make sure it doesn't dry out. Rack, sweeten if desired and bottle. [Adapted recipe from Steven A. Krause's Wines from the Wilds]
I made a 3 gallon batch a couple of years ago, came out real nice. The cloves and lemon zest gave it somewhat of a mulled spiced wine taste. Very light and delicate, took a good year of aging.