high gravity brews, and water

[user 108580]

So let's say I brew a 10 gallon recipe that calls for 25 lbs of grain. Using a water to grist ratio of 1.25 qts/lb I would use 7.8 gal in my mash. My sparge would be about 13 gal.

Now, let's say I brew a high gravity 5 gallon recipe using the same 25 lbs of grain. Obviously my mash would still be around 7.8 gallons, but how would my sparge change?

I recently ran into this problem and came out low on my efficiency.

Thanks for any advice.

 

[BrerRabbitBrew]

There's a series about being high gravity beers on Brew Strong where John Palmer and Jamil talk about that. I don't remember all the details but they said it's not possible to extract above a certain gravity without diluting your wort.

 

[billl]

Your 25lbs of grain will absorb close to 3 gallons of water. You'll be left with only 2-2.5 gallons to sparge with unless you can lengthen you boil. That certainly is going to bring your efficiency down. No real way around that.

The grain is still going to have a ton of sugar left after that sparge. You might consider sparging another couple times and just making a small beer from those runnings.