Natural Conditioning in Keg - The Answer to Mitigating Oxidation?

I have been brewing NEIPAs lately, beers that darken in the presence of oxygen, or oxidation.

I do not use CO2 to transfer from fermenter (closed transfer) to keg but do take care to limit O2 pickup by limiting splashing and purging.

The more I read about O2 pickup, I am considering keg conditioning with priming sugar to carbonate while scrubbing O2.

Is it plausible that keg conditioning with priming sugar will scrub O2 left in the beer?

The benefits of keg conditioning may also be beneficial to the hop flavor/aroma while at ambient temperature for a few weeks. My theory that is …

Since I cannot do a closed transfer, the next best thing (I hope) is keg conditioning to carbonate and scrub oxygen. Purely hypothetical at this point, just an idea.

One thing I will stop doing is shaking the crap out of the keg once I add the dry hops (and purging). I’ll shake it a couple of times a day to get the hops moving around. While the keg is always purged, I wonder if this too is not a good idea.

Your thoughts?

Firstly, you are hitting on what is typically the most interesting characteristic of excluding oxygen on the cold side for most people: loss of hop aromas and flavors. More than any other reason, we have seen an overwhelming majority of people interested in what we talk about for that reason specifically.

Forgive the liberties i’m going to take with the order of your post. I tried to structure it to make my responses flow better:

In truth, no, but it is much better than force carbonating in trying to mitigate the issue you bring up. IF you can perform a closed transfer of the finished beer and then naturally condition in the keg, it would be much more effective.

This is an excerpt from a response I made over at HBT to a question of NEIPA and oxidation:

"The yeast left after fermentation has completed are not sufficient enough to scavenge the oxygen introduced from packaging. If you plan on letting the beer finish, I would bottle ASAP with fresh, active yeast and sugar.
In order of reducing power, i’d say:
1.) Bottling with remaining extract;
2.) Bottling with partial remaining extract and supplemental sugar;
3.) Letting beer finish and dosing with fresh yeast and sugar;
4.) Traditional bottle conditioning"

You would be better served to let the beer finish, closed transfer if you can, and then add fresh yeast and sugar. Speaking of closed transfers…

What style of fermenter are you using? I’m sure we can help you come up with a feasible solution.

I think what you are pursuing is a good idea.

Big Monk …

I use a Norther Brewer Big Mouth Bubbler. To delve a little deeper, here is my post boil process.

  1. transfer to fermenter through plate chiller
  2. oxygenate through a 2 micron stone with bottled O2
  3. pitch yeast slurry (saved yeast built w/starter)
  4. cap the fermenter and add blow-off  house to container w/sanitized water
  5. move to temperature controlled fermenter
  6. take gravity sample post fermentation (carefully)
  7. transfer to keg w/ Fermtech auto-siphon
  8. fill from the bottom-up - no splashing filling hose resting @ the bottom of the keg
  9. add 1st dry hop mesh container w/hops (300 micron stainless steel mesh dry hopper)
  10. cap and purge w/CO2 - leaving CO2 attached
  11. shake the keg to keep the hops moving
  12. wait 4-5 days @ ambient temperature
  13. add 2nd dry hop mesh container w/hops (300 micron stainless steel mesh dry hopper)
  14. cap and purge w/CO2 - leaving CO2 attached
  15. shake the keg to keep the hops moving
  16. wait 4-5 days
  17. refrigerate - leaving both dry hop charges in the keg

I am careful throughout the post fermentation process to limit oxygen ingress. As careful as I can …

I do not have the means (now) to do a closed transfer w/my current equipment.

My NEIPAs, which are most telling of oxidation, aren’t bad. I don’t brew bad batches, but they do darken over time. My 5 gallon batches last 4-5 months, I am the only one drinking here :slight_smile:

So … I would like to tighten-up the post-fermentation process to further limit O2 pickup. Two things I can think of are:

  1. stop shaking the keg
  2. naturally carbonate/condition with priming sugar

What other process changes do you recommend?

You do though. Clean and sanitize the keg you are going to use. Seal the keg. Drill and add a bottling spigot on the BMB (if you don’t already have one).

You can purge the keg with fermentation CO2. Jumper the blowoff/airlock/gas out of the fermenter and the liquid post of the keg. Add your typical style of blowoff bucket/jar attached to the gas post of the keg. When ready to transfer, place the keg lower than the fermenter and jumper the liquid and gas lines of the fermenter and keg. This will close siphon the beer into the keg.

You can then either dose the yeast/sugar solution inline with a medical syringe and tee while it transfers or crack the keg lid briefly and add it.

With this method you are also able to transfer the beer for spunding should you desire. You have many more options than you are giving yourself credit for.

I would dose with new yeast and sugar if you plan on letting the beer finish in the fermentation vessel. Spent yeast and priming sugar is not sufficient to scrub oxygen.

I don’t have links or anything, but I have definitely seen YouTube videos demonstrating closed transfers from BMBs.  Do a little searching.

Check out this method I use.

https://www.homebrewersassociation.org/forum/index.php?topic=31274.0

Also, If you are kegging then I assume that you have a CO2 tank.  You can fill the keg with Sanitizer and then push it out with CO2 thus removing nearly all O2.

I think this is what Big Monk is saying but I will put it in my words.  If you have some extra hose lying around you can attach some to your gas in attachment from the keg and run the line from there to the top of the fermenter (Red line in picture).  Do a standard gravity transfer through the liquid out line (Blue line in picture) of the keg and as the keg fills it will displace the CO2.  Run the CO2 line to the fermenter and you will fill the head space with mostly CO2.  If you have the means you can drill two holes in a stopper for the siphon and the CO2 from the keg line.

I cannot seem to get the images to show so here is a link…

I don’t think there’s much you can do to expect these to last 4-5 months. You just need to drink faster or brew smaller batches.

It’s totally feasible to have beer brewery fresh in the keg for durations up to and exceeding 8 months.

Adam, your picture’s gone 404.  To illustrate the general idea, here (if my link works any better) is a pic of how I do a closed, gravity transfer on my Speidel in the way you describe. (From the time I pitch the yeast until I pour a beer into my glass, there is no exposure to the outside world. After lagering in this keg, it will be jumped to another sani-purged keg for serving, leaving sediment behind.)  A little ingenuity,  and you can adapt this idea to most any type of fermenter. (I used to use the familiar carboy cap-based solution on glass carboys.)

The OP is talking about NEIPA’s

Right. I understand that. What I am saying is that given what we know about tightening up hot and cold side practices (especially cold side), your statement about his expectations of duration not being able to touch 4-5 months are false.

Telling someone looking for process improvements that they should drink faster and brew smaller batches is bad advice.

There’s a reason standard IPA’s have a 3-6 month shelf life, let alone NEIPA’s which are much shorter. And that’s with professional equipment to mitigate oxygenation. So yes, it is unreasonable to expect homebrewed NEIPA’s to hold up over that long of a period of time, no matter what you do to reduce oxygen. Bottom line is this style is very unstable and has a short life, so yes they should be consumed quicker or brewed in smaller quantity.

I disagree heartily.

Distribution is the reason they have short shelf lives, i.e. the weakest link. We, as homebrewers, have the advantage that when brewed right, our beer is essentially brewery fresh for as long as we can maintain it that way. We don’t stale in the distribution chain. While I can grant you that under those circumstances (Brewery fresh → Distribution → Customer), NEIPA may be more fragile than other IPAs) it still doesn’t change my mind.

Stability is process related, not style related.

All of this, of course, has the feel of a pissing match, and for that I apologize and agree to disagree.

Agreed. Cheers.

How much CO2 is consumed by pushing 5 gallons of sanitzer through the keg?

How do you add keg hops using this method?

Density of CO2 is 1.977g/L, so to displace 20L of sanitizer takes 39.54g, or 1.7% of a 5lb. bottle.  At say $16 (what I pay for 5lb of CO2)  that’s $0.27 to purge a keg.  Pretty cheap, compared to dumping 5 gal of oxidized beer.

What Adam said works really well.

…and I’ll add that even at like only 2psi it doesn’t take very long at all.

How do you not overfill the keg? I brew batches >5 gallons to accommodate the loss hop absorption, fermenter loss, etc. Unless there is a way to precisely measure the throughput to not overfill.

You do overfill, carefully.  You’re pushing beer in through the liquid side,  and you want to have a tube on a disconnect on the gas side to let the gas out as liquid enters.  This can go into a pail of sani like a blowoff, or if transferring by gravity, return to the source vessel. As soon as beer is coming out the gas side, stop.  Then hook up as for dispense and push a pint or so out of the keg to get the correct fill level, and pressurized as desired.  Here are pics of both setups for closed transfer on my system, one for pressurized transfer and one for gravity. The beauty of a gravity transfer is that you don’t have to watch for when beer starts coming out the gas side.  When the level equilibrates, it stops.

Depending on you fermenter, details will vary on your rig, but the idea is the same.  I used to do this with a carboy cap-based rig on a glass carboy as many brewers do.  The principle is just gas in, liquid out, then liquid in, gas out.  Nothing but beer and CO2 in your keg then.