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General Category => General Homebrew Discussion => Topic started by: Jarhead on July 10, 2019, 11:39:20 PM

Title: Oxidation question
Post by: Jarhead on July 10, 2019, 11:39:20 PM
First time post on this forum. I’ve been brewing for decades, mostly partial mash. I went all grain a few years ago and haven’t looked back.

Lately I’ve been working on a New England ipa recipe. It’s pretty much dialed in now but now I’m chasing a problem that appears to be oxidation. I found some very  useful threads on the forum as well as some other online articles. I’m getting a gray discoloration and bitterness beyond what the calculated ibu would predict. Am I correct?

I have keg capabilities but I prefer to bottle this beer in 24oz as I like to give out to friends for gifts and feedback. Haven’t found anyone that turns away free beer!!!!! Anyway I guess I’ll purge my bottles with CO2 and use carb tabs, bottling directly from the secondary.

I currently have a batch in drinking condition. But the damn gray curse is upon it. My second question is, is it a progressive process? ie will it continue to become more oxidized in the bottle as it sits in the basement?Do i have to drink rapidly or can I relax and have a home brew for the next few weeks?

Finally, I saw some others that feel that yeast strains contribute to oxidation. I currently use wyeast 1318. Apparently it’s more prone to oxidation than a white labs strain. Can’t remember the type. Can anyone validate this? 

Thanks.

Lee


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Title: Re: Oxidation question
Post by: mabrungard on July 11, 2019, 11:25:03 AM
NEIPA undergoes significant dry hopping that can introduce more oxygen into the beer than can be consumed by yeast (if fermenting) and definitely too much if its completed fermenting. So that is one avenue for oxygen ingress. The other major avenue is if you use some form of open transfer where the beer is exposed to air for any amount of time. It sounds like your CO2 purging of bottles should help avoid oxygen, but if you're using a bottling bucket it may not be enough. 

Air-free transfers are required in beers like NEIPA.
Title: Re: Oxidation question
Post by: GoodLife Brewer on July 19, 2019, 10:32:40 PM
Cold Crashing is another huge way of introducing oxygen. Idk if you do that but there is some DIY ways of inflating a balloon with CO2 that way that gets sucked into the fermenter vs Oxygen. I just threw a batch away b/c it has severe oxidation to the point that there was no hop aroma or flavor when it took 9oz in the recipe.
Title: Re: Oxidation question
Post by: majorvices on July 20, 2019, 11:58:04 AM
As Martin suggested dry hopping can be one of the biggest factors in O2 ingress. One thing you can try is adding your hops to a keg, purging the keg with co2 then racking the beer onto the hops (via closed transfer if possible). You can also add the hops near the end of active fermentation so that the yeast scavenge the o2.
Title: Re: Oxidation question
Post by: ynotbrusum on July 20, 2019, 12:00:56 PM
Welcome to the forum to you both.  Martin Major and GoodLife are right and there are several threads you can search for here on reducing oxygen ingress during transfer to packaging.  Some very diligent homebrewers are able to reach commercial levels of reduced O2 in their total processes using techniques like purging kegs and vessels and spunding.  Cheers.

Title: Re: Oxidation question
Post by: Visor on July 20, 2019, 04:46:02 PM
Cold Crashing is another huge way of introducing oxygen. Idk if you do that but there is some DIY ways of inflating a balloon with CO2 that way that gets sucked into the fermenter vs Oxygen. I just threw a batch away b/c it has severe oxidation to the point that there was no hop aroma or flavor when it took 9oz in the recipe.
   That kinda depends on your equipment, I just stick a stopper in the airlock hole and put the FV in the fridge, my conicals are sufficiently airtight to hold what little vacuum I get from chilling - at least most of them are.
Title: Re: Oxidation question
Post by: BrewBama on July 20, 2019, 05:02:51 PM
I’ve always wondered if that would work. I thought the stopper might get sucked in with all the creepy crawlers on it so never tried it.


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Title: Re: Oxidation question
Post by: Robert on July 20, 2019, 05:18:22 PM
Trick is, if you seal it up and build a little vacuum during cooling, you're just delaying the inevitable.  When you pull the stopper, the air will rush in.  Less contact time though, maybe, if you do a quick closed-ish (it's already not closed) transfer.  If equipment permits, putting a couple of psi of CO2 on the fermentor before crashing will solve this.  It takes surprisingly little.
Title: Re: Oxidation question
Post by: denny on July 20, 2019, 06:46:31 PM
I do the best I can to avoid oxidation and then don't worry about it.
Title: Re: Oxidation question
Post by: Robert on July 20, 2019, 08:00:03 PM
I do the best I can... and then don't worry about it.
Ya know, there could be a theme for a book in there....   ;D
Title: Re: Oxidation question
Post by: Thirsty_Monk on July 20, 2019, 08:09:49 PM
As Martin suggested dry hopping can be one of the biggest factors in O2 ingress. One thing you can try is adding your hops to a keg, purging the keg with co2 then racking the beer onto the hops (via closed transfer if possible). You can also add the hops near the end of active fermentation so that the yeast scavenge the o2.
I always have experience yeast activity after dry hopping. This will take care of any free oxygen. There was a study at MBAA that talk about “dry hop creep” that some hops could have enzyme to break dextrens  and allow for refermentation.

Last thing you can have stailing of your beer even with out oxygen due to too much FAN and fatty acids.

I am like a walking knowledge. I just returned from Malt U :)
Title: Re: Oxidation question
Post by: Richard on July 20, 2019, 08:25:23 PM
Last thing you can have stailing of your beer even with out oxygen due to too much FAN and fatty acids.

Yes. Although the LODO people use the term oxidation to refer to all staling, there other mechanisms.
Title: Oxidation question
Post by: Thirsty_Monk on July 21, 2019, 01:42:17 AM
Last thing you can have stailing of your beer even with out oxygen due to too much FAN and fatty acids.

Yes. Although the LODO people use the term oxidation to refer to all staling, there other mechanisms.
The issue is not that simple.

It is barley variety dependent. If barley variety would have less FAN then it would have more Bata Glucain and via versa. Yeast needs some FAN but if too much is left over, that will make stailing.

You can find FAN levels from Malt Analyses.
Title: Re: Oxidation question
Post by: Robert on July 21, 2019, 02:35:32 AM
Last thing you can have stailing of your beer even with out oxygen due to too much FAN and fatty acids.

Yes. Although the LODO people use the term oxidation to refer to all staling, there other mechanisms.
The issue is not that simple.

It is barley variety dependent. If barley variety would have less FAN then it would have more Bata Glucain and via versa. Yeast needs some FAN but if too much is left over, that will make stailing.

You can find FAN levels from Malt Analyses.
The particular staling mechanism involved is called Strecker (sp?) degradation, in case that might direct you to further sources.

While FAN should be available on the COA, it may be of little help if one does not have an idea of how much FAN yeast can consume in one's process.

Prudent practice is to use malt with low total nitrogen (trusting that the maltster has appropriately balanced FAN, beta glucan, and other parameters) and minimize all other risk factors for staling reactions:  mash in above 60°C, and minimize thermal loading, oxygen, etc. through the whole process, and pitch an appropriate (not excessive) amount of yeast with good vitality and viability to maximize growth.
Title: Re: Oxidation question
Post by: Bilsch on July 21, 2019, 03:34:08 AM
I do the best I can to avoid oxidation and then worry about it some more.
Title: Re: Oxidation question
Post by: Jarhead on July 21, 2019, 12:53:01 PM
Wow. Thanks for all the input. Major brew geeking out going on here. Love it.

I think the biggest problem for my brew is oxygen introduction in secondary transfer as well as in the cold crash.


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Title: Re: Oxidation question
Post by: majorvices on July 21, 2019, 01:05:23 PM
As Martin suggested dry hopping can be one of the biggest factors in O2 ingress. One thing you can try is adding your hops to a keg, purging the keg with co2 then racking the beer onto the hops (via closed transfer if possible). You can also add the hops near the end of active fermentation so that the yeast scavenge the o2.
I always have experience yeast activity after dry hopping. This will take care of any free oxygen. There was a study at MBAA that talk about “dry hop creep” that some hops could have enzyme to break dextrens  and allow for refermentation.

Last thing you can have stailing of your beer even with out oxygen due to too much FAN and fatty acids.

I am like a walking knowledge. I just returned from Malt U :)

Hop Creep is certainly real but I havent found it to be enough to avoid oxidation pitfalls.
Title: Re: Oxidation question
Post by: denny on July 21, 2019, 03:02:26 PM
As Martin suggested dry hopping can be one of the biggest factors in O2 ingress. One thing you can try is adding your hops to a keg, purging the keg with co2 then racking the beer onto the hops (via closed transfer if possible). You can also add the hops near the end of active fermentation so that the yeast scavenge the o2.
I always have experience yeast activity after dry hopping. This will take care of any free oxygen. There was a study at MBAA that talk about “dry hop creep” that some hops could have enzyme to break dextrens  and allow for refermentation.

Last thing you can have stailing of your beer even with out oxygen due to too much FAN and fatty acids.

I am like a walking knowledge. I just returned from Malt U :)

Hop Creep is certainly real but I havent found it to be enough to avoid oxidation pitfalls.

I actually tried to make hop creep happen to study the effects.  2 tries so far no hop creep.  3rd try coming up.
Title: Re: Oxidation question
Post by: denny on July 21, 2019, 03:02:56 PM
Wow. Thanks for all the input. Major brew geeking out going on here. Love it.

I think the biggest problem for my brew is oxygen introduction in secondary transfer as well as in the cold crash.


Sent from my iPhone using Tapatalk

Is there a reason you're using a secondary?
Title: Re: Oxidation question
Post by: Jarhead on July 21, 2019, 03:13:26 PM
Wow. Thanks for all the input. Major brew geeking out going on here. Love it.

I think the biggest problem for my brew is oxygen introduction in secondary transfer as well as in the cold crash.


Sent from my iPhone using Tapatalk

Is there a reason you're using a secondary?

Educate me please if I’m wrong. Not using a conical fermenter. Maybe I should invest.  I’m transferring to secondary for dry hop then cold crash.


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Title: Re: Oxidation question
Post by: denny on July 21, 2019, 03:59:19 PM
Wow. Thanks for all the input. Major brew geeking out going on here. Love it.

I think the biggest problem for my brew is oxygen introduction in secondary transfer as well as in the cold crash.


Sent from my iPhone using Tapatalk

Is there a reason you're using a secondary?

Educate me please if I’m wrong. Not using a conical fermenter. Maybe I should invest.  I’m transferring to secondary for dry hop then cold crash.


Sent from my iPhone using Tapatalk

Well, it sounds like you have a reason.  I seldom use a secondary but dry hopping is an exception for me.  I cold crash the primary,  xfer to secondary,  dry hop and crash again.
Title: Re: Oxidation question
Post by: Visor on July 21, 2019, 04:02:31 PM
Trick is, if you seal it up and build a little vacuum during cooling, you're just delaying the inevitable.  When you pull the stopper, the air will rush in.  Less contact time though, maybe, if you do a quick closed-ish (it's already not closed) transfer.  If equipment permits, putting a couple of psi of CO2 on the fermentor before crashing will solve this.  It takes surprisingly little.
   If you wait until the beer & vessel have returned to room temp then there is no vacuum, hence no inrushing of air when the stopper is pulled. I generally remove the FV from the fridge the day before I plan on bottling. I also do my best to purge the headspace with CO2 any time I have the lid off, i.e. sampling, dry hopping etc., I realize there will always be some infiltration of air, but every little bit of purging helps some. For those using conicals with sediment jars, I recommend purging the jar with CO2 after harvesting and before re-attaching to the FV, I know that seems obvious, but it took me a while to think of that one, but I was one of the short bus kids.
Title: Re: Oxidation question
Post by: Robert on July 21, 2019, 04:34:42 PM
Wow. Thanks for all the input. Major brew geeking out going on here. Love it.

I think the biggest problem for my brew is oxygen introduction in secondary transfer as well as in the cold crash.


Sent from my iPhone using Tapatalk

Is there a reason you're using a secondary?

Educate me please if I’m wrong. Not using a conical fermenter. Maybe I should invest.  I’m transferring to secondary for dry hop then cold crash.


Sent from my iPhone using Tapatalk

Well, it sounds like you have a reason.  I seldom use a secondary but dry hopping is an exception for me.  I cold crash the primary,  xfer to secondary,  dry hop and crash again.
I seldom dry hop, but when I do it's in the primary with some fermenting left to do.  Using the stainless mesh canisters for the hops I can even keep the yeast clean enough for harvesting and repitching.  And I'm not using a conical either.  If it's at all possible with whatever fermenter one is using, then I don't see a need for transfer.
Title: Re: Oxidation question
Post by: denny on July 21, 2019, 04:42:30 PM
Wow. Thanks for all the input. Major brew geeking out going on here. Love it.

I think the biggest problem for my brew is oxygen introduction in secondary transfer as well as in the cold crash.


Sent from my iPhone using Tapatalk

Is there a reason you're using a secondary?

Educate me please if I’m wrong. Not using a conical fermenter. Maybe I should invest.  I’m transferring to secondary for dry hop then cold crash.


Sent from my iPhone using Tapatalk

Well, it sounds like you have a reason.  I seldom use a secondary but dry hopping is an exception for me.  I cold crash the primary,  xfer to secondary,  dry hop and crash again.
I seldom dry hop, but when I do it's in the primary with some fermenting left to do.  Using the stainless mesh canisters for the hops I can even keep the yeast clean enough for harvesting and repitching.  And I'm not using a conical either.  If it's at all possible with whatever fermenter one is using, then I don't see a need for transfer.

I don't care for the effects of doing dry hops on yeast.  To me, that's worse than any possible oxidation.
Title: Re: Oxidation question
Post by: Robert on July 21, 2019, 04:48:47 PM
^^^^
Okay, there's a reason!  :)
Title: Re: Oxidation question
Post by: denny on July 21, 2019, 05:20:17 PM
^^^^
Okay, there's a reason!  :)

Yep!  It's my reason and I'm sticking with it!
Title: Re: Oxidation question
Post by: Thirsty_Monk on July 21, 2019, 05:59:26 PM
As Martin suggested dry hopping can be one of the biggest factors in O2 ingress. One thing you can try is adding your hops to a keg, purging the keg with co2 then racking the beer onto the hops (via closed transfer if possible). You can also add the hops near the end of active fermentation so that the yeast scavenge the o2.
I always have experience yeast activity after dry hopping. This will take care of any free oxygen. There was a study at MBAA that talk about “dry hop creep” that some hops could have enzyme to break dextrens  and allow for refermentation.

Last thing you can have stailing of your beer even with out oxygen due to too much FAN and fatty acids.

I am like a walking knowledge. I just returned from Malt U :)

Hop Creep is certainly real but I havent found it to be enough to avoid oxidation pitfalls.

I actually tried to make hop creep happen to study the effects.  2 tries so far no hop creep.  3rd try coming up.
Denny, you king of podcast. There was an presentation at MBAA about hop creep. You can listen to it here. http://masterbrewerspodcast.com/098-dry-hop-creep You do not have to be a MBAA member to access the podcast.

Keith, I have experienced refermentation after dry hoping after reaching terminal gravity. My only explanation is that it is availability of oxygen and enzyme activity from dry hops. Granted I was using 3.5lb/BBL.
Title: Re: Oxidation question
Post by: Thirsty_Monk on July 21, 2019, 06:03:51 PM
Last thing you can have stailing of your beer even with out oxygen due to too much FAN and fatty acids.

Yes. Although the LODO people use the term oxidation to refer to all staling, there other mechanisms.
The issue is not that simple.

It is barley variety dependent. If barley variety would have less FAN then it would have more Bata Glucain and via versa. Yeast needs some FAN but if too much is left over, that will make stailing.

You can find FAN levels from Malt Analyses.
The particular staling mechanism involved is called Strecker (sp?) degradation, in case that might direct you to further sources.

While FAN should be available on the COA, it may be of little help if one does not have an idea of how much FAN yeast can consume in one's process.

Prudent practice is to use malt with low total nitrogen (trusting that the maltster has appropriately balanced FAN, beta glucan, and other parameters) and minimize all other risk factors for staling reactions:  mash in above 60°C, and minimize thermal loading, oxygen, etc. through the whole process, and pitch an appropriate (not excessive) amount of yeast with good vitality and viability to maximize growth.
Robert, you are correct in all the points what you mentioned. Here is a presentation from last year Malt U about this topic. https://bsgcraft.com/resources/Announcements/FAN%20and%20Flavor%20impacts_Malt%20Symposium%202018.pdf?_ga=2.114860551.1029554665.1563732014-1038012913.1563732014
Title: Re: Oxidation question
Post by: majorvices on July 22, 2019, 11:41:57 AM
Denny - I have definitely experienced hop creep .... very much in unfortunate instances. Think of a $50,000 recall and you will understand how unfortunate. At YH we would force age, force ferment, and inventory EVERYTHING. I've seen it happen on more than one occasion. FYI I also believe in biotransformation... that's also a very real phenomenon. Just sayin'. ;)

The pod cast Thirsty Monk mentions is a good one. Check it out.
Title: Re: Oxidation question
Post by: Robert on July 22, 2019, 12:55:17 PM
Besides podcasts,  there are some old fashioned papers from 1893 that cover the topic pretty thoroughly; in fact I don't think I've seen anything really significant added to the subject since!  Then some more papers around 1939 (publication delayed by war) rediscovering and reexamining and confirming those.  Then the whole thing rediscovered again now....

Back in the 19th century, dry hop creep was depended upon and taken for granted.  It was the primary reason for dry hopping.  It ensured full attenuation and the elimination of sugars unfermentable by culture yeast that might feed spoilers. 

Flavor and aroma weren't considerations for dry hopping then; the beers were sufficiently aged that hop character would be nearly absent by the time of release.  The only other function was providing tannin to complex with protein and help clarification.   Like the modern use of gallotannin in the aging tank.

One thing the original studies note that I haven't seen (might have missed) addressed in the recent work is that seeded hops may contain more amylase than seedless (IIRC this assertion of the 1893 study was questioned by the 1939 work.)  I wonder if some hops today might be deseeded prior to pelletizing, leading to inconsistent results in producing dry hop creep.   Maybe there are other differences in modern varieties as well.

Title: Re: Oxidation question
Post by: goose on July 22, 2019, 01:54:22 PM

Sent from my iPhone using Tapatalk
[/quote]

Well, it sounds like you have a reason.  I seldom use a secondary but dry hopping is an exception for me.  I cold crash the primary,  xfer to secondary,  dry hop and crash again.
[/quote]

Same here, Denny.  I tried dry hopping in the conical so I didn't have to transfer and had a hell of a time kegging the beer from the conical (even after burping out most of the dry hops before starting) because iI kept plugging up my inline screen.  I only now transfer IPA's to a secondary (more precisely a brite tank), purging the hell out of the vessel prior to the transfer.  Makes things go a lot easier at kegging time which is a closed transfer.  Plus, the transfer seems to rouse the yeast a bit which adds a bit more CO2 to the head space.

Like Denny says, I do the best to minimize O2 pickup then don't worry about it.
Title: Re: Oxidation question
Post by: denny on July 22, 2019, 02:15:08 PM
As Martin suggested dry hopping can be one of the biggest factors in O2 ingress. One thing you can try is adding your hops to a keg, purging the keg with co2 then racking the beer onto the hops (via closed transfer if possible). You can also add the hops near the end of active fermentation so that the yeast scavenge the o2.
I always have experience yeast activity after dry hopping. This will take care of any free oxygen. There was a study at MBAA that talk about “dry hop creep” that some hops could have enzyme to break dextrens  and allow for refermentation.

Last thing you can have stailing of your beer even with out oxygen due to too much FAN and fatty acids.

I am like a walking knowledge. I just returned from Malt U :)

Hop Creep is certainly real but I havent found it to be enough to avoid oxidation pitfalls.

I actually tried to make hop creep happen to study the effects.  2 tries so far no hop creep.  3rd try coming up.
Denny, you king of podcast. There was an presentation at MBAA about hop creep. You can listen to it here. http://masterbrewerspodcast.com/098-dry-hop-creep You do not have to be a MBAA member to access the podcast.

Keith, I have experienced refermentation after dry hoping after reaching terminal gravity. My only explanation is that it is availability of oxygen and enzyme activity from dry hops. Granted I was using 3.5lb/BBL.

Thanks, Leos.  I'm familiar with the info in there.  It's not that I think hop creep doesn't happen.  But i dp think that homebrewers re too quick to call hop crerrp when something unexpected happens.  There's too much that isn't understood about it.
Title: Re: Oxidation question
Post by: denny on July 22, 2019, 02:17:29 PM
Denny - I have definitely experienced hop creep .... very much in unfortunate instances. Think of a $50,000 recall and you will understand how unfortunate. At YH we would force age, force ferment, and inventory EVERYTHING. I've seen it happen on more than one occasion. FYI I also believe in biotransformation... that's also a very real phenomenon. Just sayin'. ;)

The pod cast Thirsty Monk mentions is a good one. Check it out.

Keith, I'm not by any means questioning that it happens.  But I am questioning how ubiquitous it is.  And it appears that I may have stumbled on a way to prevent it, at least at the homebrew level.
Title: Re: Oxidation question
Post by: narvin on July 29, 2019, 05:51:44 PM
For what it's worth, I haven't experienced oxidation with large amounts of dry hopping during fermentation.  I have experienced almost instant oxidation, however, after keg hopping with whole leaf.
Title: Re: Oxidation question
Post by: denny on July 29, 2019, 06:04:59 PM
For what it's worth, I haven't experienced oxidation with large amounts of dry hopping during fermentation.  I have experienced almost instant oxidation, however, after keg hopping with whole leaf.

Its great that the decision is so clear for you. I don't care for the flavors I get by dry hopping during fermentation, it's not an option for me.  I now cold crash the primary, dry hop in a CO2 flushed secondary, crash again, then keg.  Works for me.
Title: Re: Oxidation question
Post by: narvin on July 29, 2019, 06:28:59 PM
For what it's worth, I haven't experienced oxidation with large amounts of dry hopping during fermentation.  I have experienced almost instant oxidation, however, after keg hopping with whole leaf.

Its great that the decision is so clear for you. I don't care for the flavors I get by dry hopping during fermentation, it's not an option for me.  I now cold crash the primary, dry hop in a CO2 flushed secondary, crash again, then keg.  Works for me.

It's style dependent, for sure, but I like the results for NE IPA types of beer using either 1318 or WLP007.

Dry hopping with pellets, directly in the primary after fermentation is complete and 5 days before cold crashing, hasn't caused oxidation issues for me either.  However, I'm still suspicious of the kegging step even with a completely purged and closed transfer, since it seems like there is a marked decrease in hoppiness after only 2 weeks.  I'm planning on moving to spunding for carbonation to test if I can detect a difference.
Title: Re: Oxidation question
Post by: denny on July 29, 2019, 07:32:24 PM
For what it's worth, I haven't experienced oxidation with large amounts of dry hopping during fermentation.  I have experienced almost instant oxidation, however, after keg hopping with whole leaf.

Its great that the decision is so clear for you. I don't care for the flavors I get by dry hopping during fermentation, it's not an option for me.  I now cold crash the primary, dry hop in a CO2 flushed secondary, crash again, then keg.  Works for me.

It's style dependent, for sure, but I like the results for NE IPA types of beer using either 1318 or WLP007.

Dry hopping with pellets, directly in the primary after fermentation is complete and 5 days before cold crashing, hasn't caused oxidation issues for me either.  However, I'm still suspicious of the kegging step even with a completely purged and closed transfer, since it seems like there is a marked decrease in hoppiness after only 2 weeks.  I'm planning on moving to spunding for carbonation to test if I can detect a difference.

Sounding is something else I can't do because I can't control my schedule well enough.  I use pellets for everything 99% of the time these days. 
Title: Re: Oxidation question
Post by: Bilsch on July 30, 2019, 02:36:32 AM
Avoid beer contact with oxygen. Experience has shown that the bottleneck air in the filling process is the main cause of high oxygen content in beer. So much oxygen content can easily cause beer oxidation. Elevated dissolved oxygen caused by the filtration process is a secondary factor causing oxidation. To prevent beer oxidation, malt: uses high-quality malt with a moisture content of less than 6% and requires a low polyphenol content.

Oh there are so many ways to oxidize a beer!
Title: Re: Oxidation question
Post by: Robert on July 30, 2019, 02:40:23 AM
Avoid beer contact with oxygen. Experience has shown that the bottleneck air in the filling process is the main cause of high oxygen content in beer. So much oxygen content can easily cause beer oxidation. Elevated dissolved oxygen caused by the filtration process is a secondary factor causing oxidation. To prevent beer oxidation, malt: uses high-quality malt with a moisture content of less than 6% and requires a low polyphenol content.

Oh there are so many ways to oxidize a beer!
I'm pretty sure this is a bot.  Reported it earlier and thought it was gone but it's back.