Calculating Mash Water Volume When Brewing with Pumpkin
Okay, so pumpkins are not in season and I'm substituting winter squash (acorn/butternut) for my pumpkin ale recipe, but the concept remains the same as if it were pumpkin. I've never brewed with pumpkin (or any other fruits/vegetables for that matter), so I have some questions.
The grain bill is 13.75 lbs. If I weren't using pumpkin I would use 1.25 quarts of mash water per pound of grain, equaling 4.3 gallons.
My questions is, if I'm adding about 8 pounds of pumpkin, do I need to increase my mash volume to account for that, and if so, by how much?
Since the pumpkin will be saturated with water, I know I don't need to account for absorption in the same way that I do with the grains, but is the water displaced by the pumpkin enough to keep the grains fully submerged? Do I need more sparge water?