Well, I say it was sugar, but in reality the amount was like:
1lb of brown sugar (instead of the little packet that Midwest gives)
1lb of light DME
6lb of Gold Amber Extract
My OG was 1.081 and FG was 1.010 (which equaled something like 9.1%).
I really hope this thing mellows out. :-( I'm not sure how much sugar pumpkin puree introduces, but I used 90oz of pumpkin steeped with my grains, so that probably added some sugar as well. What I'm really hoping is that being fully carbed will hide the bitterness. It's not overwhelming, but I can taste it.