Overshot gravity, and under volume

[Brew Beard]

my expected gravity was 1.043 with 11.5 gallons in the fermentor. I ended up 1.052 with ten gallons of water. Guess I didn't squeeze my bag enough or didn't rinse with enough water. Should I add ro water strait into fermentor and if so how much will it change the gravity?

 

[McKnuckle]

You would need to add about 2 gallons of water to turn your ten gallons of 1.052 wort into 1.043. Of course then you'll be at 12 gallons of wort, which is more than you aimed for. Alternately, if the volume is more important than the gravity, then adding 1.5 gallons of water would get you to about 1.045.

Ideally you would have boiled and then cooled the RO water, and that would need to have been done in advance, so another option is to just roll with it as is.

 

[eric19312]

If you are less than 12 hours out from pitching the yeast you are safe to add topping up water now. It can be RO or any other water so long as it doesn't contain chlorine. Boiling is optional at this stage. Lots of partial boil extract brewers top up fermenter with tap water to volume and do just fine.

However if you are past 12 hours since you pitched the yeast you should boil the topping up water for 15 minutes to get the air out of it and then protect it from oxygen until it is cool enough to add to the fermenter. Variety of ways to do that, a purged keg comes to mind. Commercial brewers frequently ferment strong and then dilute to target strength before carbonating and packaging. Its important to use deaerated water in this use to avoid oxidizing the beer.

 

[Brew Beard]

I haven't pitch the yeast yet. Asking while its still cooling in the fermenter. Thanks for the help!

 

[Brew Beard]

Its starting to ferment, 1.043 is what the tilt is reading. Thank you again.