OK, I'm exhausted after reading this whole thread. Definitely going to give this one a whirl but I still have a few questions regarding first runnings and brewing the second batch from the "spent" grains.
1. My calculator shows a 7 gallon strike and 3.5 gallon sparge for the RIS. Just to be clear: I should sparge for the RIS, correct?
2. I'm left with wet grains in my cooler. How do I know how much water to add to get a second batch?
3. I saw several comments about adding DME to the second batch to bump the gravity, but how would I know how much to add?
4. Any advice on which hops to use on the second batch?
I've been brewing for a few years but never tried something as complex as this. Thanks for any advice!
What I would do is measure the gravity of my second running and from there I would start to see how much I have to sparge to reach the pre-boiling gravity that you want. always keeping in mind an estimated gravity that you want to get post-boil. If the gravity of the second running is too light for what you want, you can increase the gravity by adding part of your first running to the second, or by making a longer boil. What I don't know is, if so much mash time of the grain will take tannins to the kettle.