Half kegging.

[Keger8tor]

I end up splitting a five gallon batch between two five gallon kegs so one of my sons can share the spoils of the brew.
My question is, with all that head space, am I risking oxidation? My supply house owner says I will get oxidation. What do y’all think?

Thanks!

 

[Rodent]

if you don't do a full CO2 purge prior to a pressure transfer into the keg ... yep, you're going to get oxidation

simply my .02 Indian Rupees, YMMV

 

[Blazinlow86]

As rodent says just make sure your doing a closed transfer. That said you should really be doing that regardless. Cheers

 

[mongoose33]

If you're properly purging before racking to the keg, you'll be fine. Otherwise....see above. ^

I fill my kegs with star-san, then put CO2 into them via the liquid OUT post so the CO2 bubbles up from the bottom. It creates bubbles filled with, you guessed it, CO2. When I get bubbles coming out of the top, I'll let them fill the underside of the lid, then put the lid into place. Voila! A keg full of only Star-San and bubbles of CO2.

I then switch the CO2 to the IN port, and then push the Star-San out to either another keg or a 5-gallon bucket. When I get to where I'm pushing CO2 instead of liquid out, I'll pull the OUT line off the keg, and then the CO2 line. I'll have a partially-pressurized keg full of only CO2 and a little residual Star-San. I'll then put an OUT QD on the liquid OUT post that is connected to tubing, and use that to blow out the residual Star-San. Before the pressure dies I'll pull the QD off, leaving me with a slightly pressurized keg full of CO2.

Purged! Now ready for racking, half-batch, full batch, doesn't matter.

BTW, if you do something like this, i.e., pushing CO2 into the star-san-filled keg via the OUT post to create bubbles, be judicious in how much pressure you add to create bubbles. Put too much in too fast and star-san will surge out of the open mouth of the keg.

Don't ask me how I know this.

 

[Keger8tor]

Hmmm.... closed transfer is something I have not done yet. I purge the keg right away after siphoning the beer into the keg seven times at 35 psi. Then hold it there for two days. This is what I was taught for a full keg. I will Need to research this method.

 

[SanPancho]

Why not just buy some 2.5 or 3gal kegs? They usually go on sale at AIH every so often, sometimes in a four pack. Less headspace means less gas volume, better odds on your o2 exposure.

 

[passedpawn]

Make 10g. Problem solved.

 

[Keger8tor]

Why not just buy some 2.5 or 3gal kegs? They usually go on sale at AIH every so often, sometimes in a four pack. Less headspace means less gas volume, better odds on your o2 exposure.

Yep. I do have two. The problem is when they are full. Lol I need to get more for sure.

 

[BBBF]

You can fill a 5 and then use co2 to push half of it into a 2.5.

 

[Keger8tor]

You can fill a 5 and then use co2 to push half of it into a 2.5.

What is f I push half of it into a five gallon? In the cases that my three gals are full.

 

[bracconiere]

just binge drink half a 5gal keg, then urinate on your son's garden, and one of these will grow!

you know the saying, "give your son a half full keg, he'll drink for a couple days....."

 

[TechFanMD]

It is tough, because smaller kegs are as much as the 5gal ones. Maybe keg condition (priming sugar) - do as close to a closed transfer as possible, purge it like crazy, then keg condition.....there must be a calculation out there for the head pressure necessary to condition a half full keg.....OR you just don't worry about it carbonating, it's just to scrub what little oxygen you got in.

I get that people do the star-san purge thing, but CO2 is not cheap nor easy in my neck of the woods.....if you can get CO2 reasonably, then definitely push a keg of star-san out and do closed xfer.

 

[Blazinlow86]

It is tough, because smaller kegs are as much as the 5gal ones. Maybe keg condition (priming sugar) - do as close to a closed transfer as possible, purge it like crazy, then keg condition.....there must be a calculation out there for the head pressure necessary to condition a half full keg.....OR you just don't worry about it carbonating, it's just to scrub what little oxygen you got in.

I get that people do the star-san purge thing, but CO2 is not cheap nor easy in my neck of the woods.....if you can get CO2 reasonably, then definitely push a keg of star-san out and do closed xfer.

I found the key to kegging happyness was when I realized that a 5lb of co2 was only a few dollars less than 20lb. Needless to say i no longer bother with the small tanks. Additionally I'm not sure doing it the way your describing would save co2. Id almost think it's more wasteful as your completely filling the keg than purging it several times rather than once at serving psi. Cheers

 

[Keger8tor]

just binge drink half a 5gal keg, then urinate on your son's garden, and one of these will grow!

View attachment 622875

you know the saying, "give your son a half full keg, he'll drink for a couple days....."

I can only seem to piss Budweiser and that just won’t do, lol!

 

[TechFanMD]

I found the key to kegging happyness was when I realized that a 5lb of co2 was only a few dollars less than 20lb. Needless to say i no longer bother with the small tanks. Additionally I'm not sure doing it the way your describing would save co2. Id almost think it's more wasteful as your completely filling the keg than purging it several times rather than once at serving psi. Cheers

Not everyone can get cylinders filled locally, or cheaply. For some, it is a $25 swap for 5lb cylinders or take time off from work to get to the place that fills and pay $15 (and drive 30 minutes each way to a town you'd never otherwise go to for anything). We don't have any 20lb fill options nearby, and from people I talked to around the country, this is not uncommon.

Admittedly, you can do a complete fill (push stat-san out) at 1or 2 psi and have nearly all CO2 even if it took a long time, and use little CO2. I think a lot of people do it at higher PSI to be done quicker, and use more CO2. My method doesn't require you to purge over and over again, as the yeast will scrub what little CO2 is left.

I'm not a PhD, but I work with gas mixes, vacuum, pressurized systems, and have a pretty good idea of how things work. I'm weak on the biology side, so how much dissolved O2 gets scrubbed by the yeast in the scenario I do not know.....but I think the O2 left in the keg will be quite small when you leave it for the yeast to consume the sugar and scrub the O2.

 

[Blazinlow86]

Not everyone can get cylinders filled locally, or cheaply. For some, it is a $25 swap for 5lb cylinders or take time off from work to get to the place that fills and pay $15 (and drive 30 minutes each way to a town you'd never otherwise go to for anything). We don't have any 20lb fill options nearby, and from people I talked to around the country, this is not uncommon.

Admittedly, you can do a complete fill (push stat-san out) at 1or 2 psi and have nearly all CO2 even if it took a long time, and use little CO2. I think a lot of people do it at higher PSI to be done quicker, and use more CO2. My method doesn't require you to purge over and over again, as the yeast will scrub what little CO2 is left.

I'm not a PhD, but I work with gas mixes, vacuum, pressurized systems, and have a pretty good idea of how things work. I'm weak on the biology side, so how much dissolved O2 gets scrubbed by the yeast in the scenario I do not know.....but I think the O2 left in the keg will be quite small when you leave it for the yeast to consume the sugar and scrub the O2.

Not really sure what to say? I guess if you can't get a 20lb filled at the place that fills 5lbs your just gonna have to pay more for gas. Keeping o2 outta your beer is a cost of doing business plain and simple. Not much you can do about it if you want top quality and shelf life. My point was liquid purging imho is a more efficient and the best way to purge a keg than filling said keg with c02 then releasing it all and doing it again 2-4 times and additionally your likely still getting more o2 in the mix. Cheers


*Edit*

After rereading your post I think we may be talking about completely different things. I'm refering to transfering finished beer from the fermentor to the keg. I see you mentioning something about the yeast consuming o2 in the serving keg but I'm not sure exactly what your saying. Are you referring to fermenting in the keg? How's the yeast getting back into the serving keg after racking off the yeast cake?. Cheers

 

[TechFanMD]

Not really sure what to say? I guess if you can't get a 20lb filled at the place that fills 5lbs your just gonna have to pay more for gas. Keeping o2 outta your beer is a cost of doing business plain and simple. Not much you can do about it if you want top quality and shelf life. My point was liquid purging imho is a more efficient and the best way to purge a keg than filling said keg with c02 then releasing it all and doing it again 2-4 times and additionally your likely still getting more o2 in the mix. Cheers


*Edit*

After rereading your post I think we may be talking about completely different things. I'm refering to transfering finished beer from the fermentor to the keg. I see you mentioning something about the yeast consuming o2 in the serving keg but I'm not sure exactly what your saying. Are you referring to fermenting in the keg? How's the yeast getting back into the serving keg after racking off the yeast cake?. Cheers

You should really read before posting. I am taking about finishing fermentation in the keg or adding priming sugar similar to bottling.

Also, yes - there is a cost to making beer - but not everybody has access of the same prices, so stop acting like we all do. There is more than one way to do things, and for those who can’t get 20lb cylinders filled at a reasonable price....we find other ways, and they may be better and cheaper IN OUR CIRCUMSTANCES than what you can do....and no matter how much you recommend against it we cannot do it your way without paying ridiculous prices or spending a lot of time traveling and time off of work to get it done. Plain and simple, using up bought CO2 is not the only way (not is what I suggested the only way).

 

[Blazinlow86]

You should really read before posting. I am taking about finishing fermentation in the keg or adding priming sugar similar to bottling.

Also, yes - there is a cost to making beer - but not everybody has access of the same prices, so stop acting like we all do. There is more than one way to do things, and for those who can’t get 20lb cylinders filled at a reasonable price....we find other ways, and they may be better and cheaper IN OUR CIRCUMSTANCES than what you can do....and no matter how much you recommend against it we cannot do it your way without paying ridiculous prices or spending a lot of time traveling and time off of work to get it done. Plain and simple, using up bought CO2 is not the only way (not is what I suggested the only way).

Forgive me your so far off topic I was confused as to what you were talking about. I'll repost the question at hand that my post refer to


Half kegging

I end up splitting a five gallon batch between two five gallon kegs so one of my sons can share the spoils of the brew.
My question is, with all that head space, am I risking oxidation? My supply house owner says I will get oxidation. What do y’all think?

Thanks!


Not sure we're you got the idea op doesn't have co2 and is fermenting his beer in his serving kegs but I might have missed it later on Cheers

 

[TechFanMD]

Forgive me your so far off topic I was confused as to what you were talking about. I'll repost the question at hand that my post refer to


Half kegging

I end up splitting a five gallon batch between two five gallon kegs so one of my sons can share the spoils of the brew.
My question is, with all that head space, am I risking oxidation? My supply house owner says I will get oxidation. What do y’all think?

Thanks!


Not sure we're you got the idea op doesn't have co2 and is fermenting his beer in his serving kegs but I might have missed it later on Cheers

I never said he is fermenting in serving kegs. Again - please read or move on.

And the OP said “My supply house owner says I will get oxidation. What do y’all think?” and my answers were very on topic as solutions to reduce the affect of oxidation in half kegs which I do have experience in as I often bottle half, keg half.

I simply pointed out - especially as people will look back at this question (a very good one) in the future that there are options for those who cannot easily or reasonably obtain CO2 to be doing a lot of full volume purging.

You assumed he could expend a lot of CO2 just and I answered as if he cannot. My advice is for those who cannot and you, as someone who can get 20lb CO2 tanks filled economically should ignore my advice to him. Neither of us is wrong — it depends on your circumstances.

 

[Blazinlow86]

I never said he is fermenting in serving kegs. Again - please read or move on.

And the OP said “My supply house owner says I will get oxidation. What do y’all think?” and my answers were very on topic as solutions to reduce the affect of oxidation in half kegs which I do have experience in as I often bottle half, keg half.

I simply pointed out - especially as people will look back at this question (a very good one) in the future that there are options for those who cannot easily or reasonably obtain CO2 to be doing a lot of full volume purging.

You assumed he could expend a lot of CO2 just and I answered as if he cannot. My advice is for those who cannot and you, as someone who can get 20lb CO2 tanks filled economically should ignore my advice to him. Neither of us is wrong — it depends on your circumstances.

Sounds like it's working great for you and if op doesn't have access to co2 at a reasonable price he can adopt it to his next brew. Cheers

 

[Keger8tor]

If you're properly purging before racking to the keg, you'll be fine. Otherwise....see above. ^

I fill my kegs with star-san, then put CO2 into them via the liquid OUT post so the CO2 bubbles up from the bottom. It creates bubbles filled with, you guessed it, CO2. When I get bubbles coming out of the top, I'll let them fill the underside of the lid, then put the lid into place. Voila! A keg full of only Star-San and bubbles of CO2.

I then switch the CO2 to the IN port, and then push the Star-San out to either another keg or a 5-gallon bucket. When I get to where I'm pushing CO2 instead of liquid out, I'll pull the OUT line off the keg, and then the CO2 line. I'll have a partially-pressurized keg full of only CO2 and a little residual Star-San. I'll then put an OUT QD on the liquid OUT post that is connected to tubing, and use that to blow out the residual Star-San. Before the pressure dies I'll pull the QD off, leaving me with a slightly pressurized keg full of CO2.

Purged! Now ready for racking, half-batch, full batch, doesn't matter.

BTW, if you do something like this, i.e., pushing CO2 into the star-san-filled keg via the OUT post to create bubbles, be judicious in how much pressure you add to create bubbles. Put too much in too fast and star-san will surge out of the open mouth of the keg.

Don't ask me how I know this.

View attachment 622737

After doing this, don’t I still have to open the top of the keg to fill it with beer?

 

[mongoose33]

After doing this, don’t I still have to open the top of the keg to fill it with beer?

No, that would defeat the purpose. You rack to the keg through tubing connected to a black Liquid quick disconnect. You then either open the PRV on top of the keg to let out CO2 as it fills or, as some of us do, hook up a gas QD with tubing that returns the displaced CO2 from the keg as it fills back into the fermenter, so you're not drawing air into the fermenter as it drains and oxidizing the beer.

This shows the general idea:

When I first did this I didn't have anything to fit the tubing coming off the keg, so I cut off an airlock to allow for connection to the tubing. Nothing holy about using an airlock. Now, I have a stopper with a piece of rigid tubing in it, something I cut from a bottling wand, and that's what I use when I do this.

Since I'm pretty nuts about trying to keep O2 away from my beer post-fermentation, I'll even use a little residual CO2 pressure from the keg to blow out the line from the fermenter to the keg before I attach it, and blow out the line from the keg to the fermenter too. You can decide for yourself how ridiculous you want to get in doing this.

 

[applescrap]

I end up splitting a five gallon batch between two five gallon kegs so one of my sons can share the spoils of the brew.
My question is, with all that head space, am I risking oxidation? My supply house owner says I will get oxidation. What do y’all think?

Thanks!

Just fill half the keg and enjoy it. He will drink it before too long I assume. So what. So there is a little oxygen in there, it will still be plenty good for plenty long. Sure if you were going to age it for 6 months or longer and or wanted to enter competitions there is a better way, but for your son to enjoy 2.5 gallons just dump it in there and enjoy. Maybe somewhere down the line try pressure transfer. I am near wanting to pressure transfer and eliminating o2 on cold side, but doubt I'll ever do it. Enjoy your hard work and do your best. Maybe after kegging fill and pop 20 or 30 times, you will be fine. Jmo

 

[BrewInspector]

Yep, it is already done.
Discussions about a closed transfer and priming for natural carbonation in the keg are not answering the original question. They are options for the future.

Will you get some oxidation? Probably.

It is not an instantaneous process and develops over time. The OP purged the keg reducing the oxygen like most non-closed transfer Brewers.

It is not entirely due to the amount of beer vs the unused space. Consider how much O2 is in that space in contact with the beer. Purging as the OP mentioned reduced that potential exposure as well as they could at the time with what they had.

 

[Keger8tor]

No, that would defeat the purpose. You rack to the keg through tubing connected to a black Liquid quick disconnect. You then either open the PRV on top of the keg to let out CO2 as it fills or, as some of us do, hook up a gas QD with tubing that returns the displaced CO2 from the keg as it fills back into the fermenter, so you're not drawing air into the fermenter as it drains and oxidizing the beer.

This shows the general idea:

View attachment 623000

When I first did this I didn't have anything to fit the tubing coming off the keg, so I cut off an airlock to allow for connection to the tubing. Nothing holy about using an airlock. Now, I have a stopper with a piece of rigid tubing in it, something I cut from a bottling wand, and that's what I use when I do this.

Since I'm pretty nuts about trying to keep O2 away from my beer post-fermentation, I'll even use a little residual CO2 pressure from the keg to blow out the line from the fermenter to the keg before I attach it, and blow out the line from the keg to the fermenter too. You can decide for yourself how ridiculous you want to get in doing this.

It took me a while, but now I get it.
Thanks! I appreciate everyone’s input!
Cheers!

 

[applescrap]

No, that would defeat the purpose. You rack to the keg through tubing connected to a black Liquid quick disconnect. You then either open the PRV on top of the keg to let out CO2 as it fills or, as some of us do, hook up a gas QD with tubing that returns the displaced CO2 from the keg as it fills back into the fermenter, so you're not drawing air into the fermenter as it drains and oxidizing the beer.

This shows the general idea:

View attachment 623000

When I first did this I didn't have anything to fit the tubing coming off the keg, so I cut off an airlock to allow for connection to the tubing. Nothing holy about using an airlock. Now, I have a stopper with a piece of rigid tubing in it, something I cut from a bottling wand, and that's what I use when I do this.

Since I'm pretty nuts about trying to keep O2 away from my beer post-fermentation, I'll even use a little residual CO2 pressure from the keg to blow out the line from the fermenter to the keg before I attach it, and blow out the line from the keg to the fermenter too. You can decide for yourself how ridiculous you want to get in doing this.

I can see myself doing this. Thanks. This is what I have been looking for. What do you think of those caps from Bobby at bh. I think it goes on top of that with 2 ss tubes. Anyways thanks for sharing best practice and a realistic way to do it. Super solid.

 

[NitrogenWidget]

CO2 if 5$ to fill a 5lb tank but I still have plan a trip even though the welding joint is 15 mins. away because their hrs of operation conflict with mine 5 days a week.

I've done closed transfer with purged kegs and siphon transfer then purge to get beer off the sediment before travel and honestly they floating after a weekend most times but sometimes I bring them home and they still taste great for weeks after.

Closed is quicker and simpler for me.

I know oxidation is a real thing, but I've never had a beer in kegs alter from it so much that it tastes different and I use a siphon to get the beer into the keg from the fermenting bucket and keep backup kegs for months in the basement or back of the keggorator.

I think people have turned oxidation into some kind of bogeyman thinking their beer will ruin itself in a few days from it.

 

[mongoose33]

CO2 if 5$ to fill a 5lb tank but I still have plan a trip even though the welding joint is 15 mins. away because their hrs of operation conflict with mine 5 days a week.

I've done closed transfer with purged kegs and siphon transfer then purge to get beer off the sediment before travel and honestly they floating after a weekend most times but sometimes I bring them home and they still taste great for weeks after.

Closed is quicker and simpler for me.

I know oxidation is a real thing, but I've never had a beer in kegs alter from it so much that it tastes different and I use a siphon to get the beer into the keg from the fermenting bucket and keep backup kegs for months in the basement or back of the keggorator.

I think people have turned oxidation into some kind of bogeyman thinking their beer will ruin itself in a few days from it.

You're lucky. It's $16-18 to fill a 5# tank where I am.

 

[NitrogenWidget]

You're lucky. It's $16-18 to fill a 5# tank where I am.

I can't believe that really.
but then again I have the great lakes in my backyard and my water bill is higher than my cousin's in Arizona so go figure.

 

[Blazinlow86]

You're lucky. It's $16-18 to fill a 5# tank where I am.

It's 22$ here for 5lb and 25$ for 20lb..... Most new brewers I know cheap out and buy the 5lb to start with (myself included) then need to worry about conservation. Cheers