Oxidation - Where am i going wrong

[sicktght311]

I've got my NEIPA recipes down perfected (in my eyes and taste) as they taste incredible and spot on after kegged and carbonated. But i'm battling (what i perceive) as an oxidation problem that I cannot chase down for the life of me. I'm pretty much ready to give up on Flaked Oats, and move from a Chronical BME to a Unitank just to chase this dragon!

Oxidation - Typically i'm not seeing immediate degredation of color, as it stays pretty straw orange juice colored for at least 3 weeks, however the hop flavors that are vibrant, fruity, juicy, and pungent about a week after kegging and carbonating, quickly give way to sticky sweetness, and a definite reduction in hop aroma after about a week after that. So i'm going from fermenter to oxidized in about 2 weeks. It goes from Pineapple/Guava/Orange juice flavor, to a muted candied peach flavor. Its drinkable, but definitely not that traditional NEIPA burst of hops that it has in the beginning.

Fermentation Equipment/Process - Chronical BME, with blow off into sanitizer jar. First hop addition (if i'm double dry hopping) is typically just thrown in about 36 hours after fermentation starts. Once i'm on the back end of fermentation, i have a hop dropper setup. Using 3" butterfly valve on top, 3" Sight glass filled with hops, and 3" Gas post on top. I'll flush with 10-12psi of co2 purging the space in the hop dropper about 8-10x, reduce pressure to 3-4psi, then drop hops, close, pop the blow off back on, and let it finish fermenting. Once done, i close the butterfly, put on the 3" triclamp Gas fitting, purge the space, and then fill the fermenter with 3-4psi co2 and cold crash leaving it connected the entire time on 3-4psi

Transfer Process - I'll fill the keg with 5 gallons of sanitizer, purge headspace with 12psi 8-10x. Then push sanitizer out to another donor keg with co2 until empty. Then i'll attach my triclamp strainer to the racking valve, and the other end to the liquid out on the keg, which pressurizes the strainer. Then i loosen the triclamp at the racking valve to let co2 bleed out purging the strainer until theres only maybe a couple psi left in the keg. I attach a hose to the gas post of the keg into a bucket of water which relieves the remaining pressure in the keg and provides an "airlock" while transferring. Then before i transfer into the keg, i'll pull the QD off the liquid out post, open the racking valve, and push the poppet in on the QD until liquid comes out so it fills the strainer and line and gets any remaining air pockets out. Reconnect to the keg, and then transfer (all while co2 pushing in from the top of the fermenter). Once done, disconnect everything, pop it in the keezer and i put it on 12 psi, purge the headspace again 10-12times, and then let it sit a week to carbonate

All things considered, this should be pretty much rock solid for oxygen mitigation, so i'm not really sure where i'm going wrong, but i'm consistently losing that hop aroma and oxidizing over time. I've even gone so far as to leave the liquid connections in the keezer disconnected when not in use, thinking somehow oxygen is getting in there, but even that sounds unreasonable.

 

[CascadesBrewer]

Maybe there is a flaw somewhere that opens your beers up for oxidation, but it sounds like you have lots of equipment and steps in place to prevent that. I wonder if oxidation is not the issue.

How stable is the haze character in your beers? I have only brewed a handful of NEIPAs, but with my early tries I tended to see the haze level start to drop after a few weeks in the keg with a corresponding reduction in saturated hop flavors. What are you doing for water chemistry and pH adjustments? What does a typical recipe of yours look like? You could try to give a keg a gentle shake to see if the hop characters return.

 

[sicktght311]

Maybe there is a flaw somewhere that opens your beers up for oxidation, but it sounds like you have lots of equipment and steps in place to prevent that. I wonder if oxidation is not the issue.

How stable is the haze character in your beers? I have only brewed a handful of NEIPAs, but with my early tries I tended to see the haze level start to drop after a few weeks in the keg with a corresponding reduction in saturated hop flavors. What are you doing for water chemistry and pH adjustments? What does a typical recipe of yours look like? You could try to give a keg a gentle shake to see if the hop characters return.

-Haze is typically not a problem. Even when the beer oxidizes in color, its still hazy
-Water Chemistry is usually based around Long Island water profile which is typically already pretty good. Campden tablet when filling the kettles for chloramine, then for NEIPAs i typically add a little bit of CaCl, and Gypsum to bring the levels up slightly for a rounder mouthfeel.
-Mash PH is measured 10 minutes in, and i adjust accordingly, tho typically its not far off and only occasionally requires adjusting
-Recipe that i've been sticking with is typically 60-70% Pilsner Malt, then 50/50 Flaked Oats and Flaked Wheat. If its a milkshake IPA i add .75lbs-1lb of Lactose, and maybe 4oz of Honey Malt depending on recipe. Sometimes i do a bittering hop, sometimes i dont. If i do, its a FWH of around .5oz Warrior or Columbus, then i typically do a large whirlpool of 6-8oz at 180 for 25 minutes. First dryhop is usually 3-4oz, and 2nd dryhop is 4-6oz depending on what hops i'm using (ie: something like citra and mosaic i'll go on the lower side, but if its Hull Melon, or Mandarina, or something like that, i increase.
-Will try shaking the keg, but i think i've done that in the past and it didnt seem to make a difference. Will try that tonight.

 

[marc1]

I'm jealous of your sight glass dry hopper!

Since you're all in on O2 mitigation, check out the discussion here on purging, especially doug's post. 10 purges at 10PSI leaves you with ~1200ppm O2.

https://www.homebrewtalk.com/threads/keg-purging-with-active-fermentation.628658/

 

[sicktght311]

I'm jealous of your sight glass dry hopper!

Since you're all in on O2 mitigation, check out the discussion here on purging, especially doug's post. 10 purges at 10PSI leaves you with ~1200ppm O2.

https://www.homebrewtalk.com/threads/keg-purging-with-active-fermentation.628658/

Correct me if i'm wrong, but that chart is based on purging a full empty keg. My 8-10 purges of 10psi are only on the small headspace before pushing liquid out, followed by a liquid pushed purge with sanitizer via co2, so the concentrations are SIGNIFICANTLY lower than that.

 

[marc1]

Correct me if i'm wrong, but that chart is based on purging a full empty keg. My 8-10 purges of 10psi are only on the small headspace before pushing liquid out, followed by a liquid pushed purge with sanitizer via co2, so the concentrations are SIGNIFICANTLY lower than that.

The chart is size independent. The readout is ppm.

So, yes - the final will be lower because it gets diluted out with the "pure" CO2. But the gas in the area being purged will be 1200ppm.

 

[Nubiwan]

Tried any ascorbic acid (AA) in them there NEIPAs? Anyone else? Its a standard antioxidant in many foods. Vitamin C I trust.

Used AA (1 teaspoon for 5 gallons) in my bottles and happy to report they all stayed pretty crisp for the 2 months they lasted in the fridge. YMMV.

Might be worth trying if you don't have means to be completely LODO. Which applies to most bottlers I'd assume, and quite a few keggers. I reckon a good percentage of home brewers have trouble limiting O2 exposure..

Oxidation Ascorbic Acid Thread

 

[Consigliere]

Tried any ascorbic acid (AA) in them there NEIPAs? Anyone else? Its a standard antioxidant in many foods. Vitamin C I trust.

Used AA (1 teaspoon for 5 gallons) in my bottles and happy to report they all stayed pretty crisp for the 2 months they lasted in the fridge. YMMV.

Might be worth trying if you don't have means to be completely LODO. Which applies to most bottlers I'd assume, and quite a few keggers. I reckon a good percentage of home brewers have trouble limiting O2 exposure..

Oxidation Ascorbic Acid Thread

This was going to be my suggestion as well. Everything else seems like very good practices.

 

[sicktght311]

i've always been leary of adding anything to a keg, as since i purge by filling with sanitizer and pushing it out, that would mean i would have to open the keg back up again to get the AA into it, negating the purpose of the completely closed co2 purge. I suppose just before transfer, i could mix it in a little boiled and chilled water and add it at the top of the fermenter like i was dryhopping. I just find it hard to believe that it seems other homebrewers are having no problem with NEIPAs and oxidation, and using the same methods as myself. So i'm just going nuts trying to figure out where i'm going wrong, short of not purging headspaces with co2 3x more than i am now.

 

[Consigliere]

i've always been leary of adding anything to a keg, as since i purge by filling with sanitizer and pushing it out, that would mean i would have to open the keg back up again to get the AA into it, negating the purpose of the completely closed co2 purge. I suppose just before transfer, i could mix it in a little boiled and chilled water and add it at the top of the fermenter like i was dryhopping. I just find it hard to believe that it seems other homebrewers are having no problem with NEIPAs and oxidation, and using the same methods as myself. So i'm just going nuts trying to figure out where i'm going wrong, short of not purging headspaces with co2 3x more than i am now.

Do it in the mash. 4-6g in mash accomplishes the same thing is my understanding. I follow the Genus Brewing advice on this.

 

[Nubiwan]

i've always been leary of adding anything to a keg, as since i purge by filling with sanitizer and pushing it out, that would mean i would have to open the keg back up again to get the AA into it, negating the purpose of the completely closed co2 purge. I suppose just before transfer, i could mix it in a little boiled and chilled water and add it at the top of the fermenter like i was dryhopping. I just find it hard to believe that it seems other homebrewers are having no problem with NEIPAs and oxidation, and using the same methods as myself. So i'm just going nuts trying to figure out where i'm going wrong, short of not purging headspaces with co2 3x more than i am now.

Yeah, I can see that, but I have no such control over oxygen getting at my beer, and I trust the oxidation effect takes a week or two (perhaps longer) to rear its ugly head, so perhaps the AA will elongate that "lag". Or simply add to the mash, as was suggested to me also, but since my process is quite oxygen tolerant, I add it when I please. For me, its a simple solution that has worked when I have tried it.

NB : Anecdotal evidence I am providing at very best I must admit.