Oatmeal Stout

[ninjai21]

Brewing my first oatmeal stout - 5 gallon. My stupid questions are as follows, does this make sense? ....I do the mash using 3 gallon of water then follow that up with the sparge - 2 gallons. after the sparge i do a 60 minute hop/wort boil. should i boil the grains again? should i bump up the water amounts to say 5 gallons for the mash, 5 gallons for the sparge?

 

[myndflyte]

So you're going to have to have in idea of what your boil off rate is. A good starting point is 1 gallon per hour. So you'd want about 6 gallons at the start of your boil. In addition, the grains are going to absorb water which you aren't going to get back. Again, a good starting point for that is about 0.125 gal/lb of grain. So a grain bill of 12 lbs will absorb about 1.5 gal of water. So you'll need a total of 7.5 gal of water to get 6 gal of water to boil to end up with 5 gal of water in your ferementer (this isn't accounting for any equipment loss, mind you). I think a good recommendation is to mash and sparge with equal amounts of water so you'll use 3.75 gal for each.

Take a look at this calculator to get a better idea Sparge Water Calculator | MoreBeer

Oh, one thing I forgot, don't boil the grains. You should be mashing around 151F or so. Which leads to determining what to heat your water to to account for mash tun and grain temp loss. Just search for any strike water temperature calculator.