Stupid question:
I'm currently doing extract with steeped grains, boiling my wort in a stock pot. I think that produces about two gallons of "concentrated" wort which is combined with three gallons of water to create five gallons of wort that I then pitch and ferment.
If I were to go all-grain and end up with a five gallon batch, would I create 11 gallons of "malted water" which then needs to be boiled down to 5 gallons of wort and doesn't require any further water addition?
I am confused about this as well. I have a 7.5 gallon brew pot and realized that I can't really do anything with over 8.5 lbs of grain (if I have done the math correctly). Even with a small grain bill of 8.5 lbs, I calculated that you need 6.91 gallons of water. What use is a 5 gallon mash tun for batch sparging? I planned on buying a 10 gallon, but it seems worthless given that I only have a 7.5 gallon brew pot. Am I going to need more?