Partial Mash Question

I am applying an PM ingredient kit (Oatmeal Stout) to the Beer Smith program. The program is telling me to mash with 5 quarts of water and to sparge with 3.56 gallons of water. This is my first time using Beer Smith. The mash volume seems about right with 4 lbs of grain, but the sparge amount seems higher than most info that I have read about. Is this correct? Thanks

What size boil are you planning? Under equipment, you can click "choose" and put what size pot you're using and that will adjust the sparge volume. And under the recipe you choose the mash profile. Chose one (medium body, batch sparge) for example and that should fix it.

I chose Full Body Single Infusion-Batch Sparge. This is for a 5 gallon batch with a boil volume of 4.08 gallons. The boil volume was set by the Beer Smith program. I have done two PMs and, based on an article that I read, sparged with about the same amount of water as I used in the mash. That is why the 3 + gallons confused me.

Well, in my partial mash batches, I think I sparged with about twice the water I mashed with.

You can change the boil volume to whatever you want in Beersmith. If you want to boil 6 gallons for a 5 gallon batch, you can just change the settings.

That seems like a lot of sparge water to me, too. If you used 5 quarts for the mash, you should only need about 10 quarts for the sparge or so. Too much sparge water can lead to tannin extraction and astringency in the beer, particularly if you use higher temperature sparge water.

Beersmith can't quite figure everything out on its own, so I would use part of that sparge water for top-up water for your boil instead. As long as you get enough in the kettle to boil, it should all turn out fine.