I made a maple wine in 2013 that turned out great. It was a 4 1/2 gallon batch with a total of 1 1/2 gallons of grade B maple syrup. I started with 1 gallon maple syrup for a 4 gallon batch and this gave me a starting gravity of 1.086. After 10 days it had dropped to 1.040 and I decided the staring gravity was too low for a true wine so I added another 1/2 gallon of maple syrup which brought the gravity up to 1.066 (If I had added all of the maple syrup at first starting gravity would have been about 1.112). I also added more yeast nutrient and some energizer. Final gravity at the two month mark was 0.988. WOW! This fermented to 16.5%! I decided to treat this like a port and I aged it with some pecan rum-soaked oak cubes from Texas Star Distillery. I then back-sweetened it with 4 cups of maple sugar (gravity went up to 1.012) that I rendered from the remaining maple syrup and fortified with 2% brandy like a Port. It is amazing. I made another batch this year but added 1 cup less of the maple sugar.
Here is my recipe:
1 gallon maple syrup
add water to 4 gallons
4 tsp yeast nutrient
2 cups raisins
6 yeast energizer tablets (these were 15 year old tablets i got back in college - brand unknown)
When the gravity dropped to 1.040 I added:
1/2 gallon maple syrup
1 tsp. yeast nutrient
4 yeast energizer tablets.
When fermentation finished (Gravity-0.988) I added 4 ounces of the rum-soaked oak cubes and let them sit for a month. Then I racked, added the maple sugar (4 cups) and 12 ounces of good quality brandy.