CO2 purging barrels/cornys. How do you do it?

[Buffers brewery]

Looking at various threads there seems to be at least 4 methods.

Method 1
Pressurise the container (barrel or corny) with CO2 from a regulated gas cylinder. Vent and repeat 3 or more times.
Method 2
Fill the container with water and, after sealing it closed, displace the water with CO2 from a regulated gas cylinder until all the water is displaced leaving the container full of CO2.
Method 3
Connect the fermenter to the container with a length of tubing so the gas produced during fermentation passes through the container and vents through a bubbler to atmosphere.
Method 4
Collect fermentation gas from fermenter using mylar balloons (2 or 3 required depending on size). Fill container with water and seal closed. Connect a suitable length of pipe to the beer out connection sufficient to create a syphon to extract the water from the container. Connect a balloon to the gas IN connection so that as the water is syphoned out of the container CO2 is sucked from the balloon into the container until all the water is removed and the container is full of fermentation gas (CO2).

Is there a fifth and which method do you use?

 

[QED]

Method 2 but ChemSan, not just water. Kill 2 birds and all that.

 

[thegrantickle]

Method 2 but ChemSan, not just water. Kill 2 birds and all that.

This. The only way to guarantee it is both fully purges with CO2 and also sanitary. If you fill it with water and blast it out, how do you know there were no microbes in the water?

 

[Leon103]

Method 1

 

[Broken Toe]

If you didn't want to fill to 19l with chemsan then use a combination of one and two with some shaking around before the transfer.

 

[Buffers brewery]

When I say “water” I’m assuming the container has already been sanitised with chemsan or the like. I’ve just started method 4 having sanitised my barrel by shaking a gallon of Chemsan around and leaving it for a few minutes before draining it and refilling with tap water.

 

[The-Engineer-That-Brews]

Method 2 is what I do, as I've been using my full size CO2 bottle with profligate abandon for more than 12 months and I'm yet to see any detectable drop in pressure.
Don't get me wrong, I can see the intellectual attraction of collecting fermentation gasses but financially I just don't see the point :-)

 

[Buffers brewery]

Method 2 is what I do, as I've been using my full size CO2 bottle with profligate abandon for more than 12 months and I'm yet to see any detectable drop in pressure.
Don't get me wrong, I can see the intellectual attraction of collecting fermentation gasses but financially I just don't see the point :-)

It's not financial cos the cost of the stuff needed has a pretty long pay-back! I just like tinkering and making stuff complicated

 

[Tess Tickle's Brewery]

It's not financial cos the cost of the stuff needed has a pretty long pay-back! I just like tinkering and making stuff complicated

Me too, as long as I'm not required to mutilate any innocent bits of metal / plastic

I like method 3, with a little bit of method 1 at the end to make doubly sure.

 

[foxbat]

I'm yet to see any detectable drop in pressure.

And you won't see a drop until it's empty. Do you have a standby?

 

[The-Engineer-That-Brews]

And you won't see a drop until it's empty. Do you have a standby?

Good point - however the depot is just 20mins across town (and I do have a Sodastream bottle adaptor)

 

[foxbat]

Good point - however the depot is just 20mins across town (and I do have a Sodastream bottle adaptor)

That's good to hear. A brewer that has beer but no way to dispense it is not a pretty sight.

 

[The-Engineer-That-Brews]

That's good to hear. A brewer that has beer but no way to dispense it is not a pretty sight.

I'd be sucking it outa the pipes....

 

[Marko85]

Method 2 but add sodium metabisulfite - Sterile and purged?

 

[hoppyscotty]

Recently I've sanitised first with about 5 litres of Starsan/Chemsan, then brimmed with water and add a tiny amount of Sodium Metabisulphate (which I believe can also be used as a sanitiser so maybe no need for the starssan step) so no air in at all then push the water out with CO2.

 

[chillipickle]

I have been doing exactly the same hoppyscotty for months, touch wood has been working well.
The sodium meta bisulphate only for eating up any oxygen in the water, thanks to home brew net work for that idea.

 

[Davegase]

I like to experiment and make things complicated.
Using a fermzilla and 2 corny kegs. Clean corny kegs and fill one to the top with starsan or similar sanitiser. Start fermentation in fermzilla with no pressure and a blow off tube to purge the head space above the wort. Then connect the fermzilla to the corny keg filled with starsan and daisy chain that to the clean empty keg and fit the blow off tube to that. If required and once all the starsan has been transferred from the first keg to the second, you can disconnect the daisy chain and fit a spunding valve to the empty keg and ferment out under the required pressure.
The additional benefit is having the empty keg pressurised to the same level as the fermenter, this makes a closed transfer using gravity possible by simply connecting both gas posts and both liquid posts with the fermenter at a higher level. Then lift the prv valve on the keg briefly to get the transfer started.

 

[DocAnna]

One and Two for me with the proviso as above that I'm using Chemsan rather than water. Though option three appeals, I don't have a suitable exit port from my brewfridge to take the CO2 to purge a keg. Though I also don't bother if on the odd occasion I'm syphoning into a keg from a bucket, though with the new dip tubes and ball lock posts on my buckets I'm hoping to avoid that as well now.

 

[scomet]

A good clean and sanitise them #1

 

[BlackRegent]

I always do option 1 - the purge and vent. I have floating dip tubes in all my cornys and I find they are less effective in extracting the last of the liquid from the bottom of the keg than the fixed dip tube. I'm concerned that if I used the sanitised water displacement method then I would be left with too much sanitised water in the bottom than I would want. It would defeat the object if I then had to open the keg and tip the remaining water out.

I haven't yet suffered an oxidised beer using the purge and vent method, or at least not one that was obviously oxidised.