I now have 2 AG batches under my belt (both Edwort's Haus Pale Ale).
My question regarding boiling is this: why does it matter what you end with? Why not just top off with water?
I did the haus pale ale recipe for a 5 gallon batch (it's listed for 5.5 gal). I only have a 5 gallon pot, and so I split part of the boil into 2 pots until enough had boiled off that I could fit it all into one. At the end, I have about 4ish gallons. I pour it into the carboy (5 gal), and top off with water. Then I take a gravity reading.
As the water boils off, you're really not losing any sugars, just water. Your sugars are just getting a little more concentrated.
I guess I just don't see what the difference is between starting with 6.5 gallons at your boil and ending with 5, or starting with 5, and ending with 4, and then topping off to 5. Is there a difference?
On a side note, the first AG batch I did (first brew in about 8 years) turned out to be a light pale ale - I milled the grains in a food processor and got horrible efficiency - about 45% - combined with essentially no sparge. It's actually quite good, but low alcohol, and very refreshing. It would be great on an august day when it's 95 outside.
I got 72% this time with a decent sparge and milling with a philmill.
Thanks for the info!