Is anyone using fermentation CO2 to purge their kegs?

[DuncB]

Yes duotights do need ramming in further than that first feeling that you've pushed in enough, they don't like severe bends on the tubes immediately after the connector either.

 

[Consigliere]

I’ve been doing this with great success for over a year because of the analysis shared. If I do any
Sounding it is on the fermenter as there
Is less chance for leaks that way. I have had hoppy beers in kegs for a couple months that still tasted great. I also close
Transfer and use ascorbic in mash for combatting O2.

 

[marc1]

I’ve been doing this with great success for over a year because of the analysis shared. If I do any
Sounding it is on the fermenter as there
Is less chance for leaks that way. I have had hoppy beers in kegs for a couple months that still tasted great. I also close
Transfer and use ascorbic in mash for combatting O2.

How are you purging the kegs if you have the spunding valve on the fermenter?

 

[Consigliere]

How are you purging the kegs if you have the spunding valve on the fermenter?

Output of spunding valve to the keg

 

[Smudgey]

How are you purging the kegs if you have the spunding valve on the fermenter?

I put a T-join in before the spunding valve and a couple of duofit 1/0 valves, but you could as easily use the CO2 on exit from the valve.

I hate wasting anything and watching 25 volumes of free CO2 bubbling away peeved my scottish ancestors everytime I go to the garage for a sample. Which is admittedly quite often because of said ancestors. So I bought a few small items and now use the fermenter for purging kegs and lines, conditioning a brew in the kegerator and serving as well. It's an easy change if you already pressure ferment and have a spare keg. It's a tiny fraction of a saving - but its satisfying and filling a bottle is a 3 hour round trip for me.

After pitching I let it blowoff for a day or until its fermenting happily, then I use the T-join line from the fermenter (with the spunding valve closed/ set high) to starsan-purge a keg, then add another in series to purge that over a day or 2 as well. This all runs into a third corny and bubbles through that. Maybe the slight back-pressure keeps the krausen down, - I've never had krousen trouble anyway.

When the yeast's had a good start and the kegs are purged I attach a cheap inline regulator set at 12psi to the last keg in series. This will go to the kegerator. The inline regulator keeps the pressure backwards in the system set by the spunding valve ( now 15psi) and sets the serving pressure (12psi) forwards from there to the kegerator. When it all gets to pressure I plug it into the kegerator and leave it for most of the fermentation. This finishes conditioning a new beer/ keeps a keg at serving pressure in the kegerator for the ferment time.

At least a few volumes from the end of fermentation I remove one of the kegs sitting at 15psi to close transfer to later and up the blowtie to 30psi (bluetooth hydrometre helps to guess when). This carbonates the beer at ~18° in the fermenter to 2.5 volumes and also charges the remaining purged keg to 30psi. I find that's enough CO2 stored to keep a keg serving@ 12psi until it kicks (P1xV1=P2xV2 30psi x 20L = 12psi x 40L + 20% extra), with the bit extra for thermal contraction and for some hissing moments. Its not an exact science for me but seems to work. I plan to get an old 50L keg as a dedicated CO2 tank - it would give more flexibility around brewing times and serving multiple kegs.

 

[Bassman2003]

I clean my kegs, then soak them filled to the brim with Star San. After soaking, I dump the Star San, add ¼ tsp NaMeta to the keg and fill with warm water (to make sure the Meta dissolves).

Thanks to everybody for sharing their process. Broo, just wondering - why the sulfite addition when you just blow it out? Isn't there a risk of flavor impact if some is left behind? Also, if nothing is in the keg, what is the meta scavenging? Maybe the small amount of liquid that stays in the keg?

 

[ba-brewer]

That was the solution, but it still makes me nervous, lol.

After you first insert the tubing into the connector all the way give them a good pull back engage the o-rings.
You can also putting locking rings on them to help they stay in the locked position.
Amazon.com: JIUWU 1/4 inch Locking Clips for RO Reverse Osmosis Water Filter Fittings Pack of 50: Tools & Home Improvement

 

[Broothru]

Thanks to everybody for sharing their process. Broo, just wondering - why the sulfite addition when you just blow it out? Isn't there a risk of flavor impact if some is left behind? Also, if nothing is in the keg, what is the meta scavenging? Maybe the small amount of liquid that stays in the keg?

It's a three step process. First, clean. Second, sanitize with StarSan. Third, scavenge O2 with Meta. The keg remains sealed after adding the Meta. What little O2 that's in the keg gets bound with sulphur and discharged with the sodium when CO2 from the fermenter displaces the liquid and gases in the keg (at least that's how I understand the chemistry operates; caveat: it's been more than 50 years since I struggled through Freshman Chem 101).

There always seems to be some liquid left in the keg after the bulk of the NaMeta solution is displaced by the discharge CO2, so the keg ends up basically filled with "pure" CO2 and an ounce or two of NaMeta solution. I've shortened all my Gas-In dip tubes so that they're essentially flush with the inside of the keg. I shoot a couple psi of bottled CO2 into the keg, hold the keg upside down in a laundry sink, and then depress the keg post poppet just long enough to flush the last of the Meta solution. Ideally, the keg is now sealed from outside sources, cleaned and sanitized, and purged of oxygen displaced by CO2, ready for storage. Any residual O2 from the bottled CO2 should chemically react with any residual Meta in the keg (forming SO2?) and be vented out when the keg eventually gets filled.

In theory this should be similar to wine production where sulfites are added to the wine just before bottling. The sulfites bind with any oxygen in the wine or in the ulege (headspace between the cork and the wine). When the wine is uncorked you often get a small whiff of sulfur. The process of decanting and swirling a freshly poured glass is to let it "breathe" to dissipate that faint sulfurous smell. I'm fairly sensitive to the smell of sulphur compounds, but I can't say that I've ever noticed it in any of my beers handled this way. It could be that any sulphur gets vented out of the keg when it first gets tapped, however it's not noticeable in the glass.

 

[Bassman2003]

Great process. Thanks again!