I am the lone drinker in my household and I would like to try different recipes. I don't want to make full 5 gal. batches If you scale down a recipe, is it as simple as using percents? For ex., for 2 gal. use 40%. Thanks.
Reason is, you may boil off the same amount or even more water when you boil 2-3 gallons, instead of 5-6.
Boil off is more or less a constant for your particular heating source/kettle combination. So, keep an eye on your kettle volume while boiling.
1. Are you doing full volume boils? Or partial boils with top up in the fermenter?
2. Are you adding all your extracts at once and boil them for the full duration? Or split them, boiling half (or less) and adding the balance at flameout?
I'm asking as you may get some decreased bitterness due boiling your hops in higher gravity wort. Or some increased bitterness due to boiling in lower gravity wort.
Keep that in mind if bitterness is critical.
It's a good starting point for a recipe that you can "dial in" for your system.
Pro tip: initially, don't change the process (for example: don't switch from a "full volume" boil process to a "stove top" boil process). If you keep the process the same, there's less to worry about with regard to changes in estimated IBUs (and perceived bitterness).