diluting beer at bottling to get to target volume/abv

[MHBT]

Say you brew a beer and you overshoot the og by a mile and the volume is less then the target, for example you wanted 5 gallons at 1080 but yielded 4 gallons at 1.090 can you add the top up water along with the priming sugar at bottling to get closer to target? has anyone ever did this?

 

[z-bob]

Yes you can do that. I think it would be better to water it down in the primary at the beginning of fermentation so you don't get oxygen in your almost-finished beer.

 

[MHBT]

even after boiling the sugar solution there is still a risk of introducing o2?

 

[z-bob]

not really, if you boil all the water you add.

 

[MHBT]

Thanks alot z bob cheers

 

[eric19312]

I agree with z-bob above...in the case you described you would be better to dilute at beginning when it doesn't matter if the water you are adding has oxygen in it.

But you are right this would work with boiled water. many commercial breweries do just this. Brew at high strength and then dilute at packaging to hit ABV target. More beer from the same fermentor space. But it is key to have source of deoxygenated water. This can be boiled and then cooled but need to keep it away from oxygen while cooling. I've not figured out a practical way to do that in my home brewery yet.

The dilution at packaging step to me makes most sense when it is part of intentional strategy to get more beer from same fermentor space. I could see doing this if you were brewing something lower alcohol for a party. Brew at 8% ABV and dilute to 5% at packaging. I can get about 12 gallons out of my batch if I push it and that could be diluted to 20 gallons of 4.8% beer. If it is for a party and could be brewed shortly before consumption the oxygen issue would not scare me quite so much still I'd like to figure out a way to keep it oxygen free perhaps by boiling and kegging water while hot then filling kegs by weight with strong beer followed by topping up with the kegged water.

 

[eyebrau]

I've thought about this too, but worry about the hops dilution - how would you calculate IBUs in the finished product if you topped off in this way? If you're trying to hit style, I mean.