I have been upscaling my extract recipes to 6 gallons. I do a full boil, and beersmith recommends 7.5 gallons for a one hour boil.
I get very nervous boling more than 7 gallons in my turkey fryer. It is very close to the top of the pot, so I get worried about boil overs. Plus, the added weight makes moving the pot with stability more of a chore.
Is there any harm in boiling a lesser amount, like 6 to 6.5 gallons, then adding 1 to 1.5 gallons of bottled water at the end of the process just prior to the yeast? Will a little bit less boil volume have that much effect on the bittering hops?