Corny keg oxygen purge

[Scottsdale]

So my usual method to purge my corny keg is as follows...
Sanitize keg with Star San solution, empty keg
Place liquid and gas connectors in place
Fill keg with beer from fermenter
Place lid on and lock
Dial in carbonation PSI
Purge heads pace of oxygen with purge valve

I've read of ways to do this by swapping the liquid and gas posts, filling with Star San solution, purging solution from keg and filling with beer. I'm just confused on this particular method on how to get the beer in the keg from the fermenter.

 

[Saunassa]

I always pressurize with 25# to help seat the lid and purge.

 

[mac_1103]

I'm just confused on this particular method on how to get the beer in the keg from the fermenter.

Depends on your fermenter. Might be tricky if your FV doesn't have a spigot. I suppose you can siphon through some tubing with a QD connected to the liquid out post of the keg, but if you don't do a closed transfer you're basically defeating the purpose of purging the keg before filling it.

 

[day_trippr]

As described the only thing possibly "purged" would be the filled keg's head space. The problem then is the beer transfer was into a totally not-purged keg, which will result in latent oxidation damage to the beer therein.

Below this post there are links to a couple of threads that should explain viable ways to actually purge a keg before filling it...

Cheers!

 

[IslandLizard]

Here's a recent thread on why 100% liquid pre-purging kegs and filling through the liquid-out post is the best way (lid stays on till next cleaning):
https://www.homebrewtalk.com/thread...t-figure-out-why-this-keeps-happening.726669/
Pay special attention to @doug293cz's posts (#33 and #43):
https://www.homebrewtalk.com/thread...why-this-keeps-happening.726669/post-10252230https://www.homebrewtalk.com/thread...why-this-keeps-happening.726669/post-10252260

 

[day_trippr]

I've done (and still occasionally do) both and would argue using fermentation CO2 to purge a sealed keg is easier than a Star San purge, but either one if done right and not messed up later are the way to go.

And by "not messed up later" I would include not purging transfer lines prior to racking, pushing fermentor head space gas into the keg, and any opening of the keg after racking...

Cheers!

 

[doug293cz]

Here's a recent thread on why 100% liquid pre-purging kegs and filling through the liquid our post is the best way (lid stays on till next cleaning):
https://www.homebrewtalk.com/thread...t-figure-out-why-this-keeps-happening.726669/
Pay special attention to @doug293cz's posts (#33 and #43):
https://www.homebrewtalk.com/thread...why-this-keeps-happening.726669/post-10252230https://www.homebrewtalk.com/thread...why-this-keeps-happening.726669/post-10252260

A pre-purged keg and closed transfer are needed to minimize O2 exposure. There are two ways to adequately pre-purge a keg, without wasting a lot of bottled CO2. The first is the liquid purge mentioned in the quoted post, and this will use a minimum of 35 grams of bottled CO2 to push the liquid out of a 5 gal keg. The other is to use fermentation generated CO2 to purge the keg. This method uses no bottled CO2, but does require a fermenter that will hold at least 1 psi of pressure without leaking.

Brew on

 

[DuncB]

I'm assuming the thread title and note about it is a typo as purging with Oxygen would be disastrous for your beer.
Otherwise I'm with the advice of the other contributors as to the best approach.

 

[IslandLizard]

Might be tricky if your FV doesn't have a spigot. I suppose you can siphon through some tubing with a QD connected to the liquid out post of the keg, but if you don't do a closed transfer you're basically defeating the purpose of purging the keg before filling it.

None of my (bucket) fermenters have spigots.

Here's my priming/transfer method from a fermentation bucket without spigot:

Priming the racking cane and racking hose for transferring the beer:

1. Place your fermenter higher than your keg.
   • For example: fermenter on top of a table or countertop, keg on the floor.
2. Mount the racking cane to the fermenter.
3. Prepare the racking hose by filling it with Starsan.
   • This is easiest done inside a bucket with a few inches of Starsan.
   • Fill the hose by submerging it.
4. Connect a liquid keg QD to one end.
5. Lift the racking hose out of the Starsan container by the other (open) end, keeping the hose full.
6. Connect the open hose end to the mounted racking cane.
7. Depress the pin inside the QD on the bottom end of the hose, while holding it over a spill container to catch the Starsan flowing out. A few seconds later it will be followed by a Starsan/beer mix, and then, just beer.
8. As soon as the line is completely filled with beer, only beer coming out of the QD, release the QD pin to shut it and stop the flow. You don't want to waste beer.
9. Lock the keg's PRV in the [open] position, or stick an open gas QD on the gas post. Make sure any pressure inside the keg is released!
10. Connect the QD on the (low) end of the pre-primed racking hose onto the keg's liquid post, and tada...
11. ... let the keg fill with beer.

Best to rehearse the method with water and a (non-purged) keg until you get it down pat.
Once you've done it a few times it becomes 2nd nature.

Anyone with a better method, please enrich us.

 

[Scottsdale]

I'm assuming the thread title and note about it is a typo as purging with Oxygen would be disastrous for your beer.
Otherwise I'm with the advice of the other contributors as to the best approach.

Nooo....not purging WITH oxygen, purging OF oxygen. Thought that was clear.
Keg gets filled with beer, sealed, put on CO2 and then head of oxygen is then purged through purge valve.

 

[doug293cz]

I'm assuming the thread title and note about it is a typo as purging with Oxygen would be disastrous for your beer.
Otherwise I'm with the advice of the other contributors as to the best approach.

Title doesn't say purging with Oxygen, it's about purging the Oxygen.

Brew on

 

[mac_1103]

Anyone with a better method, please enrich us.

Sure. Put a spigot on your bucket.

 

[DuncB]

it's a partial purge of oxygen though.

 

[ExpatPete]

None of my (bucket) fermenters have spigots.

Here's my priming/transfer method from a fermentation bucket without spigot:

Priming the racking cane and racking hose for transferring the beer:

1. Place your fermenter higher than your keg.
   • For example: fermenter on top of a table or countertop, keg on the floor.
2. Mount the racking cane to the fermenter.
3. Prepare the racking hose by filling it with Starsan.
   • This is easiest done inside a bucket with a few inches of Starsan.
   • Fill the hose by submerging it.
4. Connect a liquid keg QD to one end.
5. Lift the racking hose out of the Starsan container by the other (open) end, keeping the hose full.
6. Connect the open hose end to the mounted racking cane.
7. Depress the pin inside the QD on the bottom end of the hose, while holding it over a spill container to catch the Starsan flowing out. A few seconds later it will be followed by a Starsan/beer mix, and then, just beer.
8. As soon as the line is completely filled with beer, only beer coming out of the QD, release the QD pin to shut it and stop the flow. You don't want to waste beer.
9. Lock the keg's PRV in the [open] position, or stick an open gas QD on the gas post. Make sure any pressure inside the keg is released!
10. Connect the QD on the (low) end of the pre-primed racking hose onto the keg's liquid post, and tada...
11. ... let the keg fill with beer.

Best to rehearse the method with water and a (non-purged) keg until you get it down pat.
Once you've done it a few times it becomes 2nd nature.

Anyone with a better method, please enrich us.

Mr. Lizard Sir and other contributors; this is all very timely as I am going to rack my first brew into a keg tomorrow rather than bottling. My beer is in a fermentation bucket without a spigot. I like your methodology listed out above, it seems straight forward and effective. I know this is probably obvious, but just to confirm, prior to the transfer process into the keg as listed above, did you liquid purge your keg?

Assuming yes do you use a method similar to Bassman2003 details in the this thread:
https://www.homebrewtalk.com/thread...t-figure-out-why-this-keeps-happening.726669/"The way I did it was in reverse - keg sits upright, fill with the lid closed tight but PRV open. Once liquid shoots out the PRV I close it and add a bare disconnect on the gas-out. The liquid then starts to come out the disconnect. While it is coming out I tilt the keg towards the liquid-in post. You will then see the liquid stop coming out for a bit (assuming that is the air pocket). I then take the disconnect off while the liquid is still coming out and it is finished."

I appreciate the advice and input!

 

[IslandLizard]

just to confirm, prior to the transfer process into the keg as listed above, did you liquid purge your keg?

Yes, since I learned about it a few years ago, I now always do it.

do you use a method similar to Bassman2003 details in the this thread:

"The way I did it was in reverse - keg sits upright, fill with the lid closed tight but PRV open. Once liquid shoots out the PRV I close it and add a bare disconnect on the gas-out. The liquid then starts to come out the disconnect. While it is coming out I tilt the keg towards the liquid-in post. You will then see the liquid stop coming out for a bit (assuming that is the air pocket). I then take the disconnect off while the liquid is still coming out and it is finished."

Yes, very similar method.
I do the Starsan (liquid) purge using CO2 from my tank. I'm not setup (yet) to use fermentation CO2 to pre-purge kegs.

I reckon it only takes around 8 gallons of CO2 to push the Starsan out, leaving the keg at 10 psi for storage. It's then clearly marked: "100% Starsan Pre-purged"
When I'll be filling the keg right away, I save some CO2 by reducing the filling pressure toward the end of the purge to around 3-5 psi.

I've incorporated a small modification to the liquid pre-purge. After pushing out about one pint of Starsan, I perform a "small headspace purge" to reduce any residual O2 in the headspace, for all security. Since it's only a pint and purge 5x at 15-20psi it's only a small amount of CO2 that's being used. I then push the rest out at 10-15 psi.

I usually also fill another (cleaned) keg with the pushed-out Starsan, through the lid opening, using a picnic tap lying on the bottom. There's hardly any foaming that way.

 

[ExpatPete]

Very good, I appreciate the input!

I may be overworking this a bit for my first keg transfer, but I figure I might as well learn the best method first rather than learning through trial and error. That is why I subscribed and support HBT. These forum discussions, along with Palmer's How To Brew (4th Ed.), and my local brewing club (Star City Brewers Guild in Roanoke, VA) have been my knowledge base as I settle into my new retirement hobby!

 

[IslandLizard]

I may be overworking this a bit for my first keg transfer

In what way would you foresee overworking this?

The one thing that's proven to be a bit tricky is to keep the racking cane, with the attached racking tubing, from moving or even flipping out of the fermenter. I use standard 6.5 gallon brew pails, and clip the racking cane to the side, about half way down the beer level. Then lower it slowly, to keep it submerged, as the beer surface drops. It tilt the bucket toward the cane when I get to the last gallon (and a half) or so, to keep the siphoning well deep.

There's also one of those inverter tippies clipped to the bottom of the cane, to prevent sucking up trub. With that method I can siphon almost all the beer out, without transferring any trub/yeast, leaving only a few ounces of beer on the yeast cake, just enough to swirl it up when I want to save the yeast cake out for a next batch.

 

[IslandLizard]

I think many of these processes benefit from practicing with a dry run (well, a wet run in our case) using water or Starsan, before committing to beer.

 

[ExpatPete]

I think many of these processes benefit from practicing with a dry run (well, a wet run in our case) using water or Starsan, before committing to beer.

Thank you again. I do like the idea of a wet run to practice. I am comfortable with the racking cane as I have been using that for my transfers into my bottling bucket with the priming sugar addition, but I want to see how the QD pin depression, liquid flow step best works.

I use my lovely Assistant Braumeisterin (my wife of 42 years) to help steady the racking cane, it never wants to stay steady. I am blessed in many ways but two of them are that my wife enjoys helping me with brewing and she loves to play golf!

 

[ExpatPete]

Yes, since I learned about it a few years ago, I now always do it.


Yes, very similar method.
I do the Starsan (liquid) purge using CO2 from my tank. I'm not setup (yet) to use fermentation CO2 to pre-purge kegs.

I reckon it only takes around 8 gallons of CO2 to push the Starsan out, leaving the keg at 10 psi for storage. It's then clearly marked: "100% Starsan Pre-purged"
When I'll be filling the keg right away, I save some CO2 by reducing the filling pressure toward the end of the purge to around 3-5 psi.

I've incorporated a small modification to the liquid pre-purge. After pushing out about one pint of Starsan, I perform a "small headspace purge" to reduce any residual O2 in the headspace, for all security. Since it's only a pint and purge 5x at 15-20psi it's only a small amount of CO2 that's being used. I then push the rest out at 10-15 psi.

I usually also fill another (cleaned) keg with the pushed-out Starsan, through the lid opening, using a picnic tap lying on the bottom. There's hardly any foaming that way.

Quick update and of course, more questions!

Everything went well on the first try of racking to a keg. Very pleased.
- Initial cleaning of the keg with PBW and triple rinse (I bought a Kegland Bucket Blaster and it is awesome).
- Closed fill of the keg with StarSan using Bassman2003 sequence
- Purged out the StarSan using CO2 pressure using your steps outlined above
- Closed fill of the keg with beer using your steps outlined above
- Place the keg into my InkBird temp controlled keezer at 34F (this is a German Pilsner brew) for 2 - 4 weeks

So the questions are on carbonation. Since I plan to lager for two weeks is 12psi good for the time? I don't need to do a fast force carbonation since i am lagering. Also, I am leaving the CO2 cylinder attached and open to the keg for the entire two weeks? Or do I close the valve after 24 hours and let it set?

Thank you again in advance!

 

[day_trippr]

According to our favorite carbonation table 12 psi @36°F will eventually reach equilibrium at 2.67 volumes of CO2. That's definitely in the ball park for pilsners (2.5~2.7 volumes).

Put the keg on gas and leave it there for the entire time you're lagering (or at least 2.5 weeks) and it'll be perfect when the beer is ready...

Cheers!