Headspace in Secondary Carboy

Hi,

I just brewed my 1st batch (5 gal.) last weekend and I'm close to transferring to my 5 gallon better bottle for the secondary. My question is, how much headspace should I leave at the top of the carboy?

as long as you finished off fermentation in your primary, you shouldnt really need any but just a couple inches should be sufficient. i just racked a belgian wit into my carboy after 14 days in the primay, completed fermentation, and i filled it to within 1/2 inch of the bung and its been fine.

I fill to about 2 inch below the bung with cool water and have never had a problem. I would say you can put 2in or 1/2in below the bung and everything will be good.



-Nick

The other side of this question is how much is too much headspace? I racked a 5 gal (barely) to a 6+gal carboy. There is a lot of space in there. Do I need to be concerned about that?

For a primary its not to much head space. For a secondary I'm not to sure.

I usually only need to add about 2 litres or less of water to my carboy to make it within 2 inch. If you airlock is showing positive pressure you might be okay.



-Nick

> The other side of this question is how much is too much headspace? I racked a 5 gal (barely) to a 6+gal carboy. There is a lot of space in there. Do I need to be concerned about that?

This is something I'm concerned about also.

I want to get a new bucket and use my current primary as a secondary. How to brew says:

It is important to minimize the amount of headspace in the secondary fermentor to minimize the exposure to oxygen until the headspace can be purged by the still-fermenting beer. For this reason, plastic buckets do not make good secondary fermentors unless the beer is transferred just as the primary phase is starting to slow and is still bubbling steadily. Five gallon glass carboys make the best secondary fermentors. Plastic carboys do not work well because they are too oxygen permeable, causing staling.

How to Brew - By John Palmer - Using Secondary Fermentors

Click to expand...

That is putting me off using my current 25L plastic bucket primary as a secondary because it will be max 80% full and is plastic. Should I really be concerned about this - size/plastic?

PET or thick HDPE (as in a bucket) is fine as far as normal secondaries (less than 6 months, perhaps longer) go. Shape is more of a concern but if you're only doing a couple of weeks you'll probably be fine--the beer releases trapped CO2 that forms a layer over it. A carboy shape with minimal headspace is ideal.

Some headspace in the carboy is ok. I would never add water to completed beer, regardless of headspace. You're watering down the beer, as well as introducing oxygen into the beer (dissolved into the water) and also causing some splashing. Adding water at this point would introduce more oxygen into the beer than simply leaving a little headspace.

I've never used a 6 gallon carboy for secondary, but I am sure it'll be fine at least short- term, since the act of racking it "knocks" some co2 out of solution. If you've ever noticed the airlock bubbling after racking, that's whats happening. The co2 will displace the oxygen, and the beer will be fine.

For long term aging, though, I'd make sure there was very little headspace. By long term, I mean more than about 6 weeks.

TacoGuthrie said:

The other side of this question is how much is too much headspace? I racked a 5 gal (barely) to a 6+gal carboy. There is a lot of space in there. Do I need to be concerned about that?

Click to expand...

I only use 6 gallon carboys.. for my primary and secondary.. Ive done about 10+ batches now and none have been bad.

The CO2 will take up the space in there.

i have a 6.5 gallon carboy that i use on 5-gallon batches of FRUIT BEER ONLY. this is because i add the fruit to the secondary carboy and the fermentation of it begins. this will knock oxygen out of the headspace within a couple hours. but for everything else, i keep the 5-gallon carboy loaded as full as it'll go. of course, thats only if fermentation is complete, cuz i hate cleaning up crusty kraussen goodies left all over the place.

depending on the specific beer, an easy solution to this is to just not do a secondary

To give everyone an update on this topic, I decided not to top off the carboy even though I was about half a gallon short.

In hindsight, I'm glad I made the decision I did so that I didn't dilute my beer. Also, the oxygen was out of the carboy so quickly that I'm sure it didn't matter.

Is 1/2 gallon enough headspace in a secondary that is dedicated to fruits or other newly introduced sugars? I am worried that the adjuncts I add on secondary will bring that 1/2 gallon headspace up several inches and that the newly introduced sugars will start a light fermentation that may need more than a couple inches headspace. Thanks!

I think just the act of tranfering the beer to a secondary will cause a little yeast to get roused and a little bit more fermentation to happen, unless its been in a really long primary. That or off -gassing will give a layer of c02. If you have a c02 tank you can allways throw a layer of c02 in there manually.

I use to only had 6 gal carboys and used them for all my primary/secondary needs, sometimes leaving 1-2 gal of headspace. I once lagered maibock for 4 months that way. When I removed a solid bung from a neck there was positive pressure build up so I don't think oxygen has a way to get in. Never a problem, in fact I still don't know what oxidized beer taste like. I would not worry too much about it

I am also interested in the "how much is too much" headspace... If im fermenting about 3G in a 5G carboy is this something you guys would be concerned about? Im planning on racking when it hits FG and adding fruit, then leaving another week and bottling... So hopefully 2-3 weeks before they hit the bottles?

Sorry didn't mean to thread jack but im curious now.

Should i go buy a bunch of marbles and sanitize them and add them to the bottom to take up space?

If your fermenting in the carboy it will not be a problem. You will be creating a bunch of c02 that will cover the beer and protect it.