Solved my oxidation woes

[DrFuggles]

So.. Id been having problems with oxidation when kegging my beers. I had previously been bottling 3 of the 19 litres and then putting the rest into the keg. I had been careful to purge headspace in the keg several times with CO2. The primed bottles turned out fine, but the force carbed keg beer was definitely oxidised and deteriorated rapidly within 2 months.

Having dismissed poor pre-kegging process (bottles were fine) this led to two possibilities - headspace or a racking problems to my keg after I'd filled my small bottling bucket. I was SURE I'd been careful not to splash etc.

So.. having done some reading and not wanting to bin my kegs, I decided to prime the keg using dextrose (100g for 5G) rather than force carbing, in the belief that the yeast would use some/all of the dissolved oxygen during priming.

Lo and behold I now have perfect beer both in bottles and kegs. Hoping this might help others. Granted this may be "covering up" a process flaw rather than fixing it, but in the end I've turned out with superior beer, so it's a win for me.

 

[BamaPhil]

Sounds like a perfect way to solve a problem, not just cover it up! I only recently started kegging but may end up doing that in the future. A couple of my first kegged beers oxidized. I'm going to be more thorough in purging with the next few and see if that helps. If not, I'll be going the direction you did.

How long did you leave the keg at room temperature after priming?

 

[friarsmith]

Keg priming is also a great way to save some CO2

 

[DrFuggles]

It was an American IPA (19l/5G) and I used 100g dextrose in 200ml boiled water (to remove oxygen and sterilise).

Immediately after filling, I filled/purged the top of the keg a couple of times and then gave it a blast of CO2 to 25psi to ensure the keg was sealed.

There is apparently a bit of a lag time between sealing and the yeast waking up to producing CO2. Given that the CO2 in the keg starts to dissolve into the beer immediately, I wanted to give it a blast to ensure the pressure remained high enough over this time so the seal remained and I didn't lose all my carbonation while waiting for the yeasties to kick in.

I then left it in the fridge (which was turned off) at 19c/66f for 14 days then attached my gas line and tap, chilled for 24 hours to bring it to 9c. Then I set the reg to 12psi (the keg was at 15-16 so needed offgassing) and then poured.

Lovely, non-oxidised and perfectly carbonated.

Also - as mentioned above, sugar is a lot cheaper than gas for me (stupid 3.5kg cylinders which I have to drive 50 minutes to change) and I have a ton of it lying around. YMMV.

 

[DrFuggles]

Further to the above - the first pint I poured off as it was a little yeasty, but the beer was perfectly clear by pint 2.

Keg priming does produce more trub (think residue on bottle conditioned beers) but the first pint collects most of the junk around the dip tube, so pint 2 onwards are fine as long as you don't move the keg about.

 

[BeardedBrews]

It took me a long time to find my O2 problem, it turned out I didn't have a 100% tight connection where the soft tube connected to my stainless siphon stick. The very small leak was on the under side which made it hard to see, but on close inspection I found it was allowing a very small stream of tiny bubbles into the siphon hose.

Now that I found that I also discovered I had a similar leak in the bottling wand to bottling bucket connection, but I suspect I didn't notice that one because the active yeast of bottle conditioning saved me.

 

[GotPushrods]

I had been careful to purge headspace in the keg several times with CO2. The primed bottles turned out fine, but the force carbed keg beer was definitely oxidised and deteriorated rapidly within 2 months.

This isn't too surprising, there is still a ton of oxygen in the keg after a few purges. It's really not feasible to purge enough times to be effective.

I'm at the point of cutting gas tubes and using a process to StarSan fill and push each keg...then purge a big after that. I'm just now seeing 1+ year of freshness and it could still be better.

Spunding or keg conditioning really is a great method.

 

[Derp]

I'm at the point of cutting gas tubes and using a process to StarSan fill and push each keg.

I do 10-gallon batches, so I fill a keg with StarSan, push it out the OUT side and into the OUT side of the second keg. I put a GAS connector on the IN side to relieve pressure. Then I fill the kegs via gravity into the OUT side with a GAS connector on the IN side to relieve pressure. Seems to work well, but I've been thinking about priming with sugar to save the hassle of CO2 refills.

 

[kh54s10]

I do 10-gallon batches, so I fill a keg with StarSan, push it out the OUT side and into the OUT side of the second keg. I put a GAS connector on the IN side to relieve pressure. Then I fill the kegs via gravity into the OUT side with a GAS connector on the IN side to relieve pressure. Seems to work well, but I've been thinking about priming with sugar to save the hassle of CO2 refills.

I can't follow this at all.

How can you push liquid out of the out side? Do you move the dip tube to the out side? If so why don't you just push the liquid out of the liquid side?

 

[m00ps]

I can't follow this at all.

How can you push liquid out of the out side? Do you move the dip tube to the out side? If so why don't you just push the liquid out of the liquid side?

Isnt the liquid side the "out" side?

 

[GotPushrods]

I do 10-gallon batches, so I fill a keg with StarSan, push it out the OUT side and into the OUT side of the second keg. I put a GAS connector on the IN side to relieve pressure. Then I fill the kegs via gravity into the OUT side with a GAS connector on the IN side to relieve pressure. Seems to work well, but I've been thinking about priming with sugar to save the hassle of CO2 refills.

I do virtually the same thing with a small tweak. I noticed that the pressure relief hole sticks down into the lid quite a bit, trapping a LOT (well a relative 'lot' if you're shooting for shelf life) in the lid.

I cut the gas tubes flush so I could tilt the keg at a 45 with the gas post up while filling. As I pump Star-San into the liquid post, it will rush out the gas side and into another keg. I shake it slightly as this is happening until I see no bubbles. The air under the lid will eventually get pushed out

It was shocking how many bubbles will come out AFTER you think it's full. There is still a good amount of air trapped once you're "full" and overflowing the PRV and gas post.

This still doesn't address the dissolved O2 in the StarSan that will start coming out of solution as you push it out with CO2, but it's a huge start.

 

[kh54s10]

Isnt the liquid side the "out" side?

OOPS! I need more coffee, or maybe a beer!

Whew boy! Do I feel dumb!

 

[TheMadKing]

It's really not feasible to purge enough times to be effective.

It really depends on what you mean by "feasible." It can certainly be done with little effort and little CO2 waste.

Purging 15 times with 30PSI reduces the O2 in the headspace to .01 ppm. as is shown here:

The "New and Improved" versions which show ppm O2 in the headspace are below:

View attachment 360407

View attachment 360408

One complicating factor is the analysis assumes that the CO2 being used is 0 ppm O2. All CO2 has come level of O2, and you can't purge to lower O2 levels than what is in your CO2.

You can get lower O2 levels by kegging prior to completion of fermentation, and using a spunding valve to control excess CO2 build up. I haven't done an analysis on that method (yet.)

Brew on

This also uses roughly the same amount of CO2 (if not less) than doing a liquid transfer I believe (assuming you have a full keg). I do this for every brew and it's very feasible for me and my system.

 

[GotPushrods]

It really depends on what you mean by "feasible." It can certainly be done with little effort and little CO2 waste.

Purging 15 times with 30PSI reduces the O2 in the headspace to .01 ppm. as is shown here:



This also uses roughly the same amount of CO2 (if not less) than doing a liquid transfer I believe (assuming you have a full keg). I do this for every brew and it's very feasible for me and my system.

It's certainly easier to just sit there and purge 15x at 30 psi, not denying that. I'm not trying to talk anybody into a certain method, but I can tell you why I do the liquid purge.

I'm filling a keg 2x at 10 psi (1.00 atm up to 1.68 atm = 0.68 atm increase...once to push out liquid, 1 additional purge). This comes to 1.07 moles of CO2 used.

Filling from 0 psig (1 atm) to 30 psig (~ 3 atm, 2 atm increase) will use 1.57 moles * 15 purges = 23.55 moles.

This will use 22 TIMES more CO2 than liquid push wish a single insurance purge.

My main motivation is not running to get CO2 filled all the time. My 20lb transfer and utility cylinder I keep in the garage has lasted for years now.

 

[TheMadKing]

It's certainly easier to just sit there and purge 15x at 30 psi, not denying that. I'm not trying to talk anybody into a certain method, but I can tell you why I do the liquid purge.

I'm filling a keg 2x at 10 psi (1.00 atm up to 1.68 atm = 0.68 atm increase...once to push out liquid, 1 additional purge). This comes to 1.07 moles of CO2 used.

Filling from 0 psig (1 atm) to 30 psig (~ 3 atm, 2 atm increase) will use 1.57 moles * 15 purges = 23.55 moles.

This will use 22 TIMES more CO2 than liquid push wish a single insurance purge.

My main motivation is not running to get CO2 filled all the time. My 20lb transfer and utility cylinder I keep in the garage has lasted for years now.

Yep that's what I get for not doing the math, thanks!

CO2 weighs 5.56g/l @ 30 PSIG @ 20C, so 5.56*.375 = 2.085 * 15 = 31.275g of CO2 or .06lb (1.2% of a tank)
CO2 weighs 3.075gl @ 10 PSIG @ 20C so 3.075 * 2.25 = 6.918g of CO2 or .015lb (.3% of a tank)

EDIT: So my math is coming out different using this calculator to solve for molar mass (44.01) by inputting densities.

but thats still 4.5 times more CO2 that I'm using

I think you were talking about purging the entire keg BEFORE filling, and I'm talking about purging the headspace AFTER filling though?


I'm still going to be switching methods. Thanks for making me think about it lol

 

[GotPushrods]

Yep that's what I get for not doing the math, thanks!

2250mL @ 0.68 atm @ 20C with 44.01 g/mol CO2 = ~7 g of CO2 used
375mL @ 2.041 atm @ 20C with 44.01 g/mol CO2 x 15 purges = ~210g CO2


WOW! I'm going to be switching methods. Thanks for making me think about it lol

I was a little shocked myself! I SWAGd about 10x...but 22, yeah. My 20 lb cylinder wouldn't last too long!

Remember that it's going to take some finesse to get the O2 as low as you've been getting w/ the 15 purges. It's all about getting that lid gap purged.

 

[TheMadKing]

I was a little shocked myself! I SWAGd about 10x...but 22, yeah. My 20 lb cylinder wouldn't last too long!

Remember that it's going to take some finesse to get the O2 as low as you've been getting w/ the 15 purges. It's all about getting that lid gap purged.

See the edit^ I'm not sure if my math is right.. but that seems more reasonable to me.

 

[pvpeacock]

I am surprised there would be any oxidation in the forced carbed keg if it was sealed and purged 5-6 times unless the beer was splashed around when transferring or there was a leak in your siphon. I transfer beer from a conical fermenter into a keg using gravity all the time without purging the keg first. Sometimes I force carbonate and sometimes I naturally carbonate, but I have never had an oxidation issue.

 

[GotPushrods]

I think you were talking about purging the entire keg BEFORE filling, and I'm talking about purging the headspace AFTER filling though?


I'm still going to be switching methods. Thanks for making me think about it lol

Aha!!! Yes that is totally different.. I also purge a couple times after filling as well. But that's negligible. I was talking about prepping the keg before even pushing beer in.

The shelf life of even my hoppy beer has improved so drastically since focusing on O2 at transfer and packaging that I'm pretty anal about it. When you read about the parts per BILLION that the pros are shooting for, I can totally understand why it's made such a difference.

This talk about spunding and carbing in the keg has me thinking I might give it a try too. In 12 years I've never naturally carbed a single keg, might be fun!

 

[doug293cz]

It's certainly easier to just sit there and purge 15x at 30 psi, not denying that. I'm not trying to talk anybody into a certain method, but I can tell you why I do the liquid purge.

I'm filling a keg 2x at 10 psi (1.00 atm up to 1.68 atm = 0.68 atm increase...once to push out liquid, 1 additional purge). This comes to 1.07 moles of CO2 used.

Filling from 0 psig (1 atm) to 30 psig (~ 3 atm, 2 atm increase) will use 1.57 moles * 15 purges = 23.55 moles.

This will use 22 TIMES more CO2 than liquid push wish a single insurance purge.

My main motivation is not running to get CO2 filled all the time. My 20lb transfer and utility cylinder I keep in the garage has lasted for years now.

Yep that's what I get for not doing the math, thanks!

CO2 weighs 5.56g/l @ 30 PSIG @ 20C, so 5.56*.375 = 2.085 * 15 = 31.275g of CO2 or .06lb (1.2% of a tank)
CO2 weighs 3.075gl @ 10 PSIG @ 20C so 3.075 * 2.25 = 6.918g of CO2 or .015lb (.3% of a tank)

EDIT: So my math is coming out different using this calculator to solve for molar mass (44.01) by inputting densities.

but thats still 4.5 times more CO2 that I'm using

I think you were talking about purging the entire keg BEFORE filling, and I'm talking about purging the headspace AFTER filling though?


I'm still going to be switching methods. Thanks for making me think about it lol

Let's revisit the math. First it takes 13 purge cycles at 30 psi to get to 0.11 ppm O2 in the purged space, and 14 cycles to get to 0.04 ppm. So, 15 cycles is a little overkill.





I measured my total keg volume at 5.35 gal (20.25 L.) So, with 5 gal (18.93 L) of beer, you have 0.35 gal (1.325 L) of headspace. For the Star San purge at 10 psi, you start with 0 gas in the keg (ignoring the ~3 fl oz that can be trapped in the lid.) So, you are filling the keg with CO2 at 10 + 14.7 = 24.7 psi, or 24.7 / 14.7 = 1.68 atm. CO2 at 1 atm & 0˚C has a density of 1.9768 g/L (at higher temps, density is lower, so 0˚C represents worst case.) Thus the liquid purge takes:

20.25 L * 1.9768 g/L-atm * 1.68 atm = 67.25 g [/44.01 g/mol = 1.53 mol]​

Now when purging the headspace after filling @ 30 psi, you already have 1 atm of gas in the headspace, so each purge adds gas at 30 / 14.7 = 2.04 atm. So each purge cycle will use:

1.325 L * 1.9768 g/L-atm * 2.04 atm = 5.344 g [/44.01 g/mol = 0.121 mol]
13 cycles uses 13 * 5.344 = 69.47 g [/44.01 g/mol = 1.58 mol]
14 cycles uses 14 * 5.344 = 74.82 g [/44.01 g/mol = 1.70 mol]​

As the volume of beer goes down, and the headspace volume goes up, multiple headspace purges start using even more CO2 than a single liquid purge.

Brew on

 

[doug293cz]

I am surprised there would be any oxidation in the forced carbed keg if it was sealed and purged 5-6 times unless the beer was splashed around when transferring or there was a leak in your siphon. I transfer beer from a conical fermenter into a keg using gravity all the time without purging the keg first. Sometimes I force carbonate and sometimes I naturally carbonate, but I have never had an oxidation issue.

6 purges at 30 psi will leave about 265 ppm O2 in the headspace. The target for good shelf life is less than 0.2 ppm for total packaged O2 (TPO), which includes headspace contribution plus the dissolved O2 in the beer. 265 ppm in the headspace is clearly too much.

Brew on

 

[pvpeacock]

I think it's time for the Brulosopher to do an experiment looking for oxidation from the way beer is transferred from the fermenter to the keg (e.g. fully CO2 purged keg + forced transfer vs. siphon into open, unpurged keg, close lid + 5-6 CO2 purges with relief valve). If I'm doing something wrong, it would be nice to get verification. However, I've never had a beer that I would say was oxidized from my process and have never had any complaints about my beer. I'm curious if some people's practices to avoid oxidation are simply overkill.

 

[doug293cz]

I think it's time for the Brulosopher to do an experiment looking for oxidation from the way beer is transferred from the fermenter to the keg (e.g. fully CO2 purged keg + forced transfer vs. siphon into open, unpurged keg, close lid + 5-6 CO2 purges with relief valve). If I'm doing something wrong, it would be nice to get verification. However, I've never had a beer that I would say was oxidized from my process and have never had any complaints about my beer. I'm curious if some people's practices to avoid oxidation are simply overkill.

Experiments on TPO vs. storage vs. perceptible taste changes are done all the time in commercial settings. See page 21 of: http://www.craftbrewersconference.com/wp-content/uploads/2015_presentations/F1540_Darron_Welch.pdf, for one brewery's experience. They taste changes in IPA's stored at room temp for three weeks if TPO is over 0.15 ppm (150 ppb.)

I was skeptical myself until I started seeing the commercial recommendations, and hearing from HBT'ers who's IPA storage life has improved dramatically after getting OCD about O2 during kegging.

Brew on

 

[TheMadKing]

Let's revisit the math. First it takes 13 purge cycles at 30 psi to get to 0.11 ppm O2 in the purged space, and 14 cycles to get to 0.04 ppm. So, 15 cycles is a little overkill.



View attachment 362894



View attachment 362895



I measured my total keg volume at 5.35 gal (20.25 L.) So, with 5 gal (18.93 L) of beer, you have 0.35 gal (1.325 L) of headspace. For the Star San purge at 10 psi, you start with 0 gas in the keg (ignoring the ~3 fl oz that can be trapped in the lid.) So, you are filling the keg with CO2 at 10 + 14.7 = 24.7 psi, or 24.7 / 14.7 = 1.68 atm. CO2 at 1 atm & 0˚C has a density of 1.9768 g/L (at higher temps, density is lower, so 0˚C represents worst case.) Thus the liquid purge takes:

20.25 L * 1.9768 g/L-atm * 1.68 atm = 67.25 g [/44.01 g/mol = 1.53 mol]​

Now when purging the headspace after filling @ 30 psi, you already have 1 atm of gas in the headspace, so each purge adds gas at 30 / 14.7 = 2.04 atm. So each purge cycle will use:

1.325 L * 1.9768 g/L-atm * 2.04 atm = 5.344 g [/44.01 g/mol = 0.121 mol]

13 cycles uses 13 * 5.344 = 69.47 g [/44.01 g/mol = 1.58 mol]

14 cycles uses 14 * 5.344 = 74.82 g [/44.01 g/mol = 1.70 mol]​

As the volume of beer goes down, and the headspace volume goes up, multiple headspace purges start using even more CO2 than a single liquid purge.



Brew on

Thanks Doug! I was waiting for you to jump in and find out mistakes haha.

I think I actually did my math right, I just used different starting numbers than you. I assumed a 6 gallon keg volume with a 1 gallon headspace, and that the gas was at 20C (which I know is high because it cools as it expands so 0 is more accurate and conservative). And I converted my mols to lbs as that is what co2 tanks are usually measured in.

Have you done any analysis on actual effect of O2 as a function of ppm?

EDIT: Disregard the question, didn't see the 2 most recent posts, sorry

 

[Mer-man]

I apologize if this is a stupid question, but why couldn't you:
a) Pull a vacuum on the keg from the gas-in port, and cap it or reconnect it to closed CO2 line
b) Transfer from FV into keg via liquid-out port (using CO2 if the siphon doesn't transfer all)

Seems like if you had a vacuum to start with, you wouldn't need to flush the headspace much, if at all.

I imagine there'd be a little air in your transfer line from the FV, but that could be minimized by pulling the vacuum all the way up to the outlet of the FV.

Edit: Ok, I see doug already commented on the use of a vacuum:
https://www.homebrewtalk.com/showpost.php?p=6896320&postcount=5

And on a related note, I wonder what happens when you try to transfer too much into a keg Is there a way to gauge fill level (other than relying on condensation from cold beer on the exterior)?
Edit: yes, one can use weight.

 

[Mer-man]

I should add that I am pretty sold on the closed transfer with CO2 into a keg and then purging the headspace 13x at 30psi. I was just musing.

 

[Callacave]

Just a quick question. Is one purge considered a complete fill of co2 in the headspace, then disconnecting the gas line and venting all of the co2, then repeating?

Or is it filling the headspace while keeping the co2 tank connected, and then venting for a specific amount of time?

 

[DrFuggles]

I'm filling a keg 2x at 10 psi (1.00 atm up to 1.68 atm = 0.68 atm increase...once to push out liquid, 1 additional purge). This comes to 1.07 moles of CO2 used.

Filling from 0 psig (1 atm) to 30 psig (~ 3 atm, 2 atm increase) will use 1.57 moles * 15 purges = 23.55 moles.

Wow.. this escalated quickly lol

Always amazed at the knowledge and dedication of people on these forums. Thank you all!

 

[mongoose33]

Just a quick question. Is one purge considered a complete fill of co2 in the headspace, then disconnecting the gas line and venting all of the co2, then repeating?

Or is it filling the headspace while keeping the co2 tank connected, and then venting for a specific amount of time?

I think a purge is simply releasing pressure then repressurizing. Doesn't matter if it's an empty keg or just the headspace.

I've adopted a system where I push CO2 out of a cleaned keg full of Star-San, pushing it into either another cleaned keg (for the next time) or a 5-gallon bucket. That saves the Star-san for re-use, but more importantly, leaves the keg almost entirely full of CO2.

Then, when I fill it, I drain the fermenter into the keg through the OUT post so that it fills through the dip tube from the bottom up. This reduces exposure to oxygen. Then when it's full, I'll pressurize, pull the pressure relief valve a few times to purge out what remains in the headspace, and set to whatever pressure I want.

 

[KeninMN]

Damn! And folks say that bottling is too much work!

 

[jddevinn]

I do virtually the same thing with a small tweak. I noticed that the pressure relief hole sticks down into the lid quite a bit, trapping a LOT (well a relative 'lot' if you're shooting for shelf life) in the lid.

I cut the gas tubes flush so I could tilt the keg at a 45 with the gas post up while filling. As I pump Star-San into the liquid post, it will rush out the gas side and into another keg. I shake it slightly as this is happening until I see no bubbles. The air under the lid will eventually get pushed out

It was shocking how many bubbles will come out AFTER you think it's full. There is still a good amount of air trapped once you're "full" and overflowing the PRV and gas post.

This still doesn't address the dissolved O2 in the StarSan that will start coming out of solution as you push it out with CO2, but it's a huge start.

I've been shaking like crazy to get that air bubble out lately and been trying to come up with a better way.

I've taken to boiling ~6 gallons of water, then adding 100 mg/l SMB (so that the sulfate reacts with any adsorbed O2), then dosing with StarSan. I then use this to purge the kegs and don't have to worry about the dissolved O2 in the StarSan. I'll keep it stored in the last keg that I cleaned for about a month or two before moving it to my general use StarSan bucket and making another batch or degassed StarSan.

 

[drgonzo2k2]

For my brewing practices I try to walk the line between ease of use/time efficiency and sound brewing science that produces good beer. For me kegging is about a 10 minute affair, and I never wind up with oxidized beer.

When a keg kicks it gets set aside until I've got several empties, and then I just spend an hour or so one afternoon cleaning them all.

When they are clean I fill each with about 1/2 gallon of Star San and give them a good shake to sanitize.

Then I apply CO2 @ 30PSI for 10 seconds or so.

Then I use a picnic tap to pour off a little Star San ensuring that the dip tube is also sanitized.

Now I have a clean, sanitized, and pressurized keg.

When it's time to keg something I grab one of those kegs and pull on the PRV. If gas comes out then I know everything is good to go. If not, then I set the keg aside to investigate later where the CO2 leak is.

I then use the picnic tap to drain off all of the Star San. From there I simply gravity transfer from the spigot on the fermenter into the open keg.

I then purge @30 PSI 15 times and set the keg to carbonate.

CO2 is stupidly cheap here ($13 for a 20lb exchange), so it doesn't really concern me how much I use.

 

[wobdee]

I've been having good luck lately gravity feeding, adding 10mg/l SMB to the keg and force carbing. Kegs seem to stay fresh for as long as I need them.

 

[ParanoidAndroid]

How would one go about bottling a portion of the finished beer?

I like to keg the majority, but bottle about 5-10 beers. It seems like kegging the whole thing and keeping O2 down is fairly straightforward with a few ways of doing it (Early ferm transfer with spunding, CO2 fermenter transfer, several purges of the keg, starsan purges, etc). But bottling inevitably will expose some beer to oxygen. Then if you want to do both with a batch, it just complicates things more.

 

[mongoose33]

How would one go about bottling a portion of the finished beer?

I like to keg the majority, but bottle about 5-10 beers. It seems like kegging the whole thing and keeping O2 down is fairly straightforward with a few ways of doing it (Early ferm transfer with spunding, CO2 fermenter transfer, several purges of the keg, starsan purges, etc). But bottling inevitably will expose some beer to oxygen. Then if you want to do both with a batch, it just complicates things more.

You can use something like the Last Straw bottle filler from Northern Brewer, which allows for a shot of CO2 into the bottom of the bottle. Or, when I don't want to break out all the equipment, I use a "poor man's" bottle filler such as threads on here describe--and where I learned to make one.

EDITED TO Add: https://www.homebrewtalk.com/showthread.php?t=24678

And my own:



If you allow just a little bit of foam at the top and then put on a cap, that foam will displace air, leaving a headspace virtually devoid of oxygen.

I also have a growler filler that fits my taps; I've also bottled using that, but those are for nearly immediate consumption.

 

[beersk]

I'm curious if adding a little fresh yeast/krausen, say 100mL to the keg before transferring would do the trick.

 

[pvpeacock]

I'm still not convinced all this extra work is necessary, but I also do not believe in man-made global warming either.

 

[UndeadFred]

I might be an oddball, but if I have time and it's not a style that it could be detrimental (clarity) to, I always prefer to sugar prime my kegs. I didn't know why I thought it tasted better until I read the LODO stuff on the other thread (and I am skeptical on a lot of that, still).. but I think at least doing a little priming is superior to purging, and that is why. I now make sure I always make enough to fill the keg up as much as possible. I have been known to make 6 gallon batches to get five in the keg and a few in bottles... cheers....

 

[Derp]

It would be interesting to see Brülosophy or one of the homebrewing magazines do an extensive study of scientifically measured, differing amounts of oxygen in beer over a period of days/weeks/months. That could be followed by experiments on different ways of reducing oxidation (priming, purging, etc.)

I don't want my beer to degrade in days, I'd rather it not degrade too much over weeks, but it would be great if my kegs would stay somewhat fresh for several months. Help me, scientists!

 

[jddevinn]

It would be interesting to see Brülosophy or one of the homebrewing magazines do an extensive study of scientifically measured, differing amounts of oxygen in beer over a period of days/weeks/months. That could be followed by experiments on different ways of reducing oxidation (priming, purging, etc.)

I don't want my beer to degrade in days, I'd rather it not degrade too much over weeks, but it would be great if my kegs would stay somewhat fresh for several months. Help me, scientists!

The oxygen reacts quickly with the wort/beer so the concentration should dissipate as it binds and reacts.