Originally Posted by TheBiGZ
There doesn't seem to be any base malt in your partial mash. Just the dark munich? What's going to convert the starches in the pumpkin to fermentable sugars? Or is baking it sufficient? Does pumpkin have any diastatic power?
Or is this basically just a steep and no conversion is taking place?
I love pumpkin ales but I've never made one...
The pumpkins are caramelized and meant to be more of a flavoring agent than a source of fermentables. You really could get away with using considerably less pumpkin (especially if you're using canned pumpkin).
I once heard a podcast on pumpkin beers, where two brewers brewed essentially the same recipe, except one used pumpkins, while the other one didn't. The resulting beers were then used in a blind taste test. It turns out there wasn't much of a difference in flavor between the two beers, except the version with pumpkins was found to be slightly drier than the one without. The sugars extracted from pumpkins are simple sugars, so extracting and converting them is similar to adding corn or cane sugar to your beer. That said,pumpkins in general are a poor source of fermentable sugars.
The key is to caramelize the pumpkins to get some flavor out of them. Otherwise they add little to your beer.