Rice hulls are the cover for the seeds/grains of rice. They are very dry and and help filter the grain bed (if you do all grain) when you are using a sticky substance like pumpkin to prevent a stuck mash. They kind of remind me of dry pine needles but are wider. Here's a pic.
You can use real pumpkin, I used cans for the ease. I recall reading on this forums last year that a lot of people recommend using Sugar Pie pumpkins rather than the big orange jack-o-lantern style because Sugar Pie are a cooking pumpkin and has better flavor. They are much smaller so you would need more. Brewers on this site have also used butternut squash (after all pumpkin is a squash), and even, believe it or not, sweet potatoes will give you a great "pumpkin" flavor.
We are Boston Strong!
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Secondary - Empty
Kegged - Peter Piper's Pail of Pumpkin
Serving: - CoCo for Coconut Porter V2, My Funny Ballantine IPA, Surly Bender AG Clone.