Doing first AG this Sunday - does this seem right? (mash/sparge numbers)

I'm doing the NorthernBrewer Pumpkin this weekend and just wanted to make sure all these numbers sound right for my first AG brew. I'm mainly curious about the sparging as I was going to do double batch sparge but the numbers show 2 gallons each sparge, is that fine? Here's what I have below:

10.75lb grain bill
3.5 gallon mash (1.25 quarts per lb of grain)
Target temp 152
Infusion temp 165

Batch sparge x2
2 gallon volume each sparge for total of 4 gallon sparge volume
6.25 gallon boil volume

So does this seem ok? I'm basically wondering if the 3.5 gallon volume mash is cool, since it's going by the commonly accepted 1.25 quarts per pound and whether 2 gallons each sparge is enough water.

I'm going to be using 4 cans of Libby's Pumpkin and a quarter pound of rice hulls, which I've read a number of times is more than enough - is it? Thanks in advance!


Rev.

You'll probably lose .15 gallons per pound of grain in the mash due to absorption. That should (in theory) give you about 1.75 gals of first runnings. You'll want your sparge to make up the difference btw that and your expected pre-boil volume.

And, of course, you'll want to double check those volumes as you brew and make adjustments. Cheers and happy brewing!

Oh, and account for the volume of the pumpkin too.

The pumpkin is going in the mash so I was planning on using the same water volume with the pumpkin added in, should I figure differently?

I just came across Bobby M's all grain pdf and his double batch sparge seems to say just what I was planning on doing, he even used two x 2 gallon sparges which seems like I'm in the ballpark. So, in which way should I adjust the mash volume, or not?, with the 60oz of pumpkin in there? Thanks again for the help!!


Rev.

Hm, I've never done a pumpkin-in-the-mash beer, but I imagine the pumpkin will add some water just because it's kinda wet, and you'll get more out of the first runnings than the 1.75 gals I mentioned above.

I'd stick with the kit instructions, but have some extra sparge water ready just in case you come up short on the pre-boil volume. If you have too much pre-boil volume, just boil a little longer.

Rather than getting all caught up in precalculating water volumes, I would advise measuring your total runnings after the first sparge and subtract from your 6.25 gallon boil volume to get your 2nd or final sparge. Rather than precalulate, I find it easier to simply sparge to a desired preboil volume.