Topping With CO2

Hi, all.
I keep hearing about people who top off a primary (and secondary) fermenter with a layer of CO2 to save the batch from oxygen.
Is this something you all do or can I ignore this if I’m careful? I don’t want to invest in it if I can ignore it, especially because I don’t know how much of an impact it will have.

Thanks

you don’t need to top off a primary with co2 because once fermentation starts the yeast will produce their own co2 that will fill the head space in the fermenter. In fact you should be aerating your wort before fermentation because the yeast need it.

you can purge a secondary with co2. That’s a good precaution to avoid oxidation, although most people would suggest that you skip the secondary phase for most beers unless you have a reason for it. Also, most people don’t purge their secondary’s with co2, are careful with their transfer, and see no issues with oxidation.

I always purge my keg with co2. If you want to get a co2 set-up, you might as well get some 5 gallon kegs too.

Well, O2 in the primary is okay because the yeast like some amount of oxygen so that part you could scratch off your list (unless I’m not understanding your question) and eventually that small amount of O2 in the primary is going out the airlock anyway. When I rack a beer from primary to secondary, I do not bother to purge the secondary of O2. I rack to the secondary and when that’s done, I place my bung/cap and airlock on there and within a few minutes, there is positive pressure in the airlock which is from CO2 escaping from the beer inside the secondary which means that the beer has purged the secondary of O2 for you. Some might suggest that the short amount of time that the beer has contact with air is not good but I have never experienced an issue with it. On a keg… I do not purge prior to filling but when the racking is done, I connect a CO2 tank and hit it while I pull the release which should expel any O2 and fill the headspace in the keg with CO2. Hope this helps.

EDIT: S.Scoggin [skillfully] beat me to an answer. :cheers:

I pretty much transfer like Ken posted above, with good results.

Ok, great. Thanks guys. It felt like I didn’t understand something, so I wanted to check.
Happy brewing!

Ken’s methods match mine (and I’m sure many others) as well.

One thing I’ll add is that if you want to do long term bulk aging (which is what most people really mean by secondary) than a corny keg is a near perfect vessel for this. Impervious to light and oxygen, nearly unbreakable, easily purged, and doubles as a serving vessel. There’s very little reason to ever buy a secondary carboy once you have a kegging setup, just get extra kegs. In the meantime, don’t worry about it, but keep in mind “secondaries” are rarely required.

So it appears that I am the odd purger . . . . I purge kegs (and check for leaks) prior to filling. I purge secondaries prior to racking so I am not so paranoid about small splashes before the beer covers the siphon hose. I even purge my hops before freezing and storing.

Of course, I did not do any of this before I kegged, and my beer was fine. But, now that I have beer gas, why not use it for all applicable purposes?

[quote=“ALSS”]So it appears that I am the odd purger . . . . I purge kegs (and check for leaks) prior to filling. I purge secondaries prior to racking so I am not so paranoid about small splashes before the beer covers the siphon hose. I even purge my hops before freezing and storing.

Of course, I did not do any of this before I kegged, and my beer was fine. But, now that I have beer gas, why not use it for all applicable purposes?[/quote]
I don’t think you’re that odd. :wink:

Many homebrewers I know like to purge before they transfer and I don’t know if that makes them good brewers, paranoid or both. I think it comes down to what you’re used to and what has worked well for people in the past. If it works, keep doing it.

Oh and hey, don’t we all have “beer gas”? :expressionless:

Ha ha. If we’re lucky we do.

I primary, then fill keg w co2, vent, fill, vent, fill, then rack beer into keg. Then fill/vent the small headspace a few times.

What I wonder is, “how” do you squirt co2 into hops bags, etc? is there a special attachment or something for that?

[quote=“beermebeavis”]I primary, then fill keg w co2, vent, fill, vent, fill, then rack beer into keg. Then fill/vent the small headspace a few times.

What I wonder is, “how” do you squirt co2 into hops bags, etc? is there a special attachment or something for that?[/quote]
I think there is. I don’t have one but some brewers like to purge secondaries too so there must be some sort of gizmo that would let you hit any container with CO2.

No gizmo needed if you have a ball valve at the regulator and a threaded QD on the line - just unthread the QD and use the ball valve as the on/off switch for CO2. :wink:

My gizo is to use a quick disconnect http://home-brewing.northernbrewer.com/ … &view=grid

hooked to a blow gun http://www.northerntool.com/shop/tools/ … _200512859