Maple Brown Ale

I am working on improving my Brown Ale recipe with Maple syrup. I intend to use Grade B syrup (direct from the farm). In Beer Smith comments it says "If added during the boil it will add a dry, woodsy flavor. If added at bottling, the smooth maple flavor comes through." I am trying to understand why there is this difference in flavor and exactly what is behind it. Maple syrup is made by boiling sap for hours on end so it is not like honey - you are not going to loose anything from boiling it some more. I was considering using it for bottle conditioning, I have estimated about 6 ounces should do the trick for a 5 gallon batch. Does anyone have any experience with this? My current recipe includes 1.5lbs of syrup.

I wouldn't disagree with Beer Smith's comment or with your game plan.  I've done a couple Maple batches:  The first I used it in the boil, the second I used it in both the bottle and as my priming sugar.  Just as you'd expect, the second batch was sweeter.  I wouldn't have called the first batch "dry" but the syrup was definitely subtle.  Both were great!

I should add some more details. I am aiming for an O.G. of 1.051 with 5 gallons into the fermenter. 1lb2oz of Amber B syrup 15 mins from the end of boil and 6oz at bottling for carbonation.

I was really hoping some mad chemist could explain why the flavour would be different from the boil addition and the bottling addition.

I've got a maple lager fermenting in the basement right now.  Almost ten days in and there's still enough activity in it for the fermometer to read two degrees warmer than the secondary next to it.  There's a thread on it under Recipes.

How much syrup are you planning to use? That can get expensive real quick  I went to a farm that sells syrup for $60/gallon (good price), and ended up getting around twelve gallons of sap for ten bucks. I boiled half of it down to around 12oz syrup (using at least five dollars worth of propane) to add at the end of the boil, and used the rest instead of water for the mash and the beginning of the sparge.  Disappointingly, I didn't taste much maple/woodsy flavor in the original gravity sample. Hopefully it will be there in the finished brew. 

Good luck and keep us posted!