Calculating mash/strike/sparge water

[Enoch52]

Brewing friends, I'm pretty new to all-grain brewing (this will be my second batch). Could you check my math?

I've got 13.5 lbs of grain, so I'm assuming those will absorb 1.35 gal of mash water. Northern Brewer recommends a mash ratio of 1.5qts of mash water/lb for new brewers, which comes out to about 5 gal.

That leaves around 3.65 gal for the first runoff. With a 60-min boil, I was expecting to lose around 1 gal to evaporation, which would leave me with a target volume of around 6-6.5 gal.

Would you suggest NO strike water, and a 3.5 gal batch sparge? Reduce the mash volume slightly to balance the two runoffs? Reduce the mash volume further to allow for some strike water? Or is my math off somewhere?

 

[DosGatosBrewing]

This is from a group called the Green Bay Rackers that I have used a few times:
https://www.rackers.org/calcs.shtml

There is also an Excel template floating around that I have been happy with. Cant find it on the web just now

 

[Yooper]

Brewing friends, I'm pretty new to all-grain brewing (this will be my second batch). Could you check my math?

I've got 13.5 lbs of grain, so I'm assuming those will absorb 1.35 gal of mash water. Northern Brewer recommends a mash ratio of 1.5qts of mash water/lb for new brewers, which comes out to about 5 gal.

That leaves around 3.65 gal for the first runoff. With a 60-min boil, I was expecting to lose around 1 gal to evaporation, which would leave me with a target volume of around 6-6.5 gal.

Would you suggest NO strike water, and a 3.5 gal batch sparge? Reduce the mash volume slightly to balance the two runoffs? Reduce the mash volume further to allow for some strike water? Or is my math off somewhere?

Well, you have to use some strike water to get your mash wetted, so definitely 5 gallons for strike water sounds fine. Then, if you're batch sparging, you would drain that and could easily measure it (mark a spoon or something so you can see your volumes at a glance), and then sparge with enough water to get you to your boil volume, probably about 2.75-3 gallons if you want to be at 6.5 gallons. I'd probably plan on 6 gallons or so, unless you know your boil off rate in an hour. I lose 1 gallon per hour, but you may lose more or less in the boil.