5 gallon fermenter question.

[flylock_jac]

Both my PET bottles are 5 gallon. I originally planned to split batches ,but one is in use.
I want to brew a 5 gallon batch tonight.
Can I do a concentrated batch of say 3 1/2 - 4 gallons and then top of my carboy with sterile water in a couple days when fermentation has slowed ? ,
or would I be better off just cutting the batch down in size ?
Thanx in advance for your help.

 

[Clonefarmer]

I would advise against adding water after fermentation. If you have any 1 gallon containers you can ferment the excess wort in them.

 

[flylock_jac]

I would advise against adding water after fermentation. If you have any 1 gallon containers you can ferment the excess wort in them.

that makes sense, Thanx.

 

[cataclysmcow]

I would advise against adding water after fermentation.

Assuming you could do so without aerating the beer what would be the risk in doing this? I've recently had to do the same when I used a 5gal BB for a primary on a HG IPA.I topped it off to 4gal initially for fermentation and then I added some spring water after 8 days and fermentation picked back up. What adverse reactions are you going to get from adding more water after fermentation?

 

[Clonefarmer]

Assuming you could do so without aerating the beer what would be the risk in doing this? I've recently had to do the same when I used a 5gal BB for a primary on a HG IPA.I topped it off to 4gal initially for fermentation and then I added some spring water after 8 days and fermentation picked back up. What adverse reactions are you going to get from adding more water after fermentation?

It's debatable how adverse the effects are, here is a thread about https://www.homebrewtalk.com/f39/adding-water-after-fermentation-60285/