[Jarhead]

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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[mabrungard]

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.

[GoodLife Brewer]

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.

[majorvices]

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.

[ynotbrusum]

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.

[Visor]

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.

[BrewBama]

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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[Robert]

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.

[denny]

I do the best I can to avoid oxidation and then don't worry about it.

[Robert]

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....   

[Thirsty_Monk]

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

[Richard]

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.

[Thirsty_Monk]

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.

[Robert]

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.

[Bilsch]

I do the best I can to avoid oxidation and then worry about it some more.