4gal batch in 5gal carboy?

[KFBass]

So after my last escapade with not leaving enough head space (see: Blowoff Tubes: a Haiku ) I realized I need a new 6.5gal carboy.

Then I realized, I gotta start a batch this weekend (working in the pit band for a musical, going to brew a batch for the closing week/cast party) if I'm going to hit my deadline. So I have ingredients, but no carboy.

Would a 4 gal batch leave enough room in a 5 gal carboy? Could I go higher with a blowoff tube with little to no repercussions?

I'm probably going to do it anyways, just want to know what im getting into

 

[Mirage]

We brew 5 gal batches and put them in a 6.5 gal fermenter with no blowoff. You will probably be fine with 4 gal in a 5 gal fermenter. I would do a blowoff though, just to be on the safe side.

 

[robertvrabel]

Short answer: yes you can.

Every fermentation is going to be different, I've made a batch that blew off w/o a starter... I've made a starter and maybe only got 1/2 of krausen that formed on a big beer. Its going to be different everytime, so to be safe, just put a blow off on for the first 3-4 days on every single beer you make.

 

[TheMan]

Or you can use Fermcaps (foam control)...they minimize the foam, allowing you to put more in the fermenter than normal. I've used it successfully for months.

 

[KFBass]

yeah prob not going to get fermcaps, being that i havn't seen them at my LHBS but i havn't really been looking. I'll give it a shot if they jump out at me.

Thanks everyone tho for the replies. Like I said, i'm probably just going to do it anyways. I bet i've already ruined the security deposit on my apartment anyways, might as well add some beer stains. I'll take pics this time if anything gets out of control!