Maple Syrup & ABV%

I'm curious what effect the addition of maple syrup would have on the ABV% and flavor of a beer.

I brewed a Maple Brown Ale on 11/3 from the following recipe:

6 lbs. light LME
3/4 lb. Victory malt
1/4 lb Crystal 80
1/4 lb Chocolate
8.5 oz. pure maple syrup
1 oz. Chinook
1 oz. Fuggles

On 11/3 the OG came in at 1.066, and last night I took my first reading and it came in at 1.020. Using an online calculator the ABV came in at roughly 6%, which surprised me as I was expecting something higher because of the maple syrup. I also tasted my sample, and it certainly wasn't as sweet as I was expecting either - it definitely had more of a bite than I was expecting.

The recipe didn't provide any target gravities, so I'm shooting from the hip here but I was expecting something in the range of 7-8%. Can I expect it to ferment out some more since it's only been going for 12 days? How long should I let it age to bring out the flavors?

 

From what I remember reading you will get about 2/3 of the alcohol compared to the same weight of DME. It will only ferment out about 65%. If you add it to the boil you will get a dry woody flavour. If you add it when bottling you will get the maple flavour.

 

8.5 oz. of maple sugar in 5 gallons is less than 4 points on the gravity. You have over ten times as much LME by weight and LME has a much higher sugar content than maple syrup. You're at 70% attenuation, so don't expect much more.

An ounce of Chinook will pack a punch, it will mellow a bit, but it can be really harsh.

 

It's really hard to get maple to shine through a beer recipe - you need a lot of it (more than eight or nine ounces), and you've got to get the lowest-grade stuff you can find (more impurities = more flavor). I'd be surprised if you get much maple flavor, especially with the Chinook in there.

 

I got 60 IBU's if I put the numbers in the way you did it. That would put it on the bitter side.