Another follow up question:
I've heard one option is topping off, namely doing a strong runnings of 2.5 gallons that is about twice my target OG and then topping off with 2.5 gallons of water once I put in my fermentation bucket.
My question is what if I want to do a high gravity RIS or something of the sort. I have a recipe for an oak aged Yeti clone that I'd like to try out, but the total grain bill would be ~20 lbs, which would equal about 1.6 gallons, so the most I'd be able mash that in would be 3 gallons. My understanding is that for best efficiency, I'd want 1 quart per lb in mash, but there is no way I can manage that with a five gallon capacity kettle. What will be the efficiency hit if I were to mash 20 lbs in three gallons, add another gallon via makeshift sparge, and then top off to five gallons when I put into my fermentor? Am I being too ambitious here? Should I just resign myself to a partial mash and get the rest of my gravity through an overpriced extract addition?
Primary: Winterfell Black Stout
Bottled: It's the Most Wonderful Time for a Beer Xmas Ale, Rumplepumpkin Imperial Pumpkin Porter, Walder Frey's Treacherous Smoked Mild.