OK, so as soon as this rain stops falling (Long Island, New York) i am going to go outside and brew. So I was planning a full volume mash. Five gallon batch. Do I do a cooler with 5 gallons and add the grains, or do I do as much water as I expect to need to end up with 5 gallons after the boil? Should I do 5 gallons in the full volume mash and then batch sparge with whatever is needed to make up the 6.5 gallons that I want to start my boil with? Or do I go with 8.5 gallons in the mash to collect the 6.5 gallons I want to start with?
Just passing through and although I’m not quite totally sure of the question, I would suggest checking out http://onebeer.net/batchspargecalc.shtml and filling in the specifics.
Then, you might be able to narrow down the questions a bit more.
I would check out ‘greenbayrackers.com’. Very simple site that can answer: Do I have enough room to mash in my cooler? What volume strike water? What temp strike water? How much boiling water do I need to add to raise one temp to another?
Simplest answer to your Q is to add enough water to get a mash thickness somewhere between 1.5-2.5 qt/lb. Or just fill your cooler(assuming it’s a 5G). Mash at whatever temp you choose between 145-158 for 60 minutes or so. Drain the 1st runnings and check volume, which will probably be somewhere between 2 and 3G. Then sparge with enough volume to make up the difference between your BK volume and your 1st runnings.
Good luck. The 1st time at AG it’s a little confusing, but it gets easier with practice. Just make sure you take good notes.
So I think your question is about a no-sparge mash, in which case you add enough water to get your full pre-boil volume. I do this from time to time and usually see a 5% or so drop in my efficiency.
I just experimented with a full volume mash. You add enough water to compensate for absobtion and dead space. Also add a lb or two extra grain because of the efficiency loss. If you want to do full volume mash try biab, you can use less water because you don’t have dead space which will give you a bit better efficiency.