How much headspace is too much?

[buffcoat]

First off, forgive me if this topic is in the wrong place.

I went to my LHBS and saw they had some noboil Grand Cru pretty cheap, so I made an impulse buy. The "kit" says it makes 9l, which if my conversion is right, should be about 2.5 gal. I only have 5+ gal primaries and secondaries. I know in wine making to much headspace is bad. Will I be ok with letting this stuff sit for a few weeks in a primary then bottle aging or should I just go buy a smaller primary and not risk it?

Thanks!

 

[Monstar]

I do 3 gal batches in 5 gal buckets and don't have a problem. I don't think it matters so much in primary since there's so much co2.

I heard iin secondary headspace matters more, but in my experience it hasn't made a difference.

 

[eltorrente]

It's fine. I'd leave in primary though - don't bother transferring to secondary.

 

[ACbrewer]

As long as it is in the primary, then the head space will get filled with CO2 - I wish I could remember where I saw it, but a 5 gallon of typical grav beer generates like 600 gallons of air CO2 (ie that come out of the beer - and air isn't that dense) - so the grand cru is going to do something similar - x2 the grav but 1/2 the start volume...

Anyhow, it should generate well over the 2 or 3 gallons of head space and displace any O2 (or it will get usedin the initial ferment) But if you rack, you will need to put it into something with appropriate headspace.