I made this recipe as directed in the OP in early sept. It was 3 weeks in primary and almost 5 weeks bottle conditioned. The 3 bottles I've tried so far have been harsh and astringent, but not from spices. I think what happened is the ph of pumpkin along with the low alkalinity (~40 mg/l) in my water caused a less than ideal mash ph. I've had issues before when using roasted malts in the mash without any water treatment.
Just wanted to mention this in case you have low alkalinity water and were thinking of brewing this.
Just wanted to mention this in case you have low alkalinity water and were thinking of brewing this.