NEIPA Brewers who dont have oxidation issues. Need input

[sicktght311]

I'm trying to track down my source of oxidation (or what i assume is oxidation). My NEIPAs come out incredible when out of the fermenter, and into the keg, and carbonated. The first couple of weeks they taste exactly as they should, and look exactly as they should. Within 3-4 weeks, they start dropping clearer and take more of a golden hazy color like an unfiltered blonde ale, than straw opaque NEIPA yellow. The flavor starts to mute a bit and takes on a sweeter, almost candied peach like taste. Definitely not as bright and tropical as when they come out. I havent tried swirling my keg yet in the event this isnt oxidation, but rather settling, but i doubt this is the case.

I thought my process was pretty damn O2 proof, but maybe i'm missing something. Those of you who make shelf stable NEIPAs, let me know your process.

Here's mine post boil (not going to get into Low Oxygen brewing, as yes it can help, but plenty of people and breweries are putting out solid NEIPAs without treating the pre-fermentation process differently than any other beer)

1) Wort is pumped into Chronical BME fermenter, yeast pitched, blow off cane + Silicone tubing into a jar of sanitizer
2) First Dryhop is typically day 2, and i dont take any O2 precautions here. Pop the lid, throw the hops in
3) 2nd Dryhop is usually either when i still have a few points left, so i quickly open the lid and drop them in.
3a) IF i'm post fermentation, i have a 3" Butterfly valve on top of my Chronical, which I close, remove the blow off cane, put on a 3" sight glass, with a 3" CO2 quick Disconnect plate on top. I fill the sight glass with my hop drop, put the top plate back on, purge with 2psi a number of times, then open the valve to drop the hops. Close the valve, remove the hop dropper, reinstall the blow off tube, slowly open the butterfly to let the excess co2 bubble throught he sanitizer jar, then let it continue to ferment and finish
4) Once ready for cold crash, i either drop the temp in 5 degree increments over a span of 24 hours until i reach the upper 30s. Doing so prevents suckback as no sanitizer makes it up the blowoff tube, therefore no air, unless maybe here is where i'm going wrong, and i'm leaking air in through somewhere else?.
4a) Occasionally if i'm quick crashing, i'll hook my 3" CO2 ball lock plate up to the valve at the top, and put 2-3psi on the fermenter during the crash, and then leave it connected until i transfer.
5) Once its time to transfer, i put the plate on the top, fill the fermenter to 2-3psi, and i'll typically dump trub into a bucket until it starts to run thinner, then i close up the dump port
6) I also dump about a pint worth of beer through the racking port to clean out the racking arm before transfer.
7) To pre-purge my kegs, i fill them to the top with sanitizer, connect co2 at around 15psi, burp the prv to clear the headspace, then i'll connect it to a line on my keezer, and open the tap into a bucket. This clears the keg of sanitizer, clears the serving line of any cleaner or anything left from a previous beer i might have just unhooked, and fills the keg with co2 as its emptying. I would assume this means the keg is fairly well purged of co2 since co2 was continually pushing the sanitizer out.
8) Once the keg is empty and ready, I put together my transfer line. It is a 1.5" Triclamp 100micron inline stainless strainer on the racking valve, to 1.5" Triclamp plate with hose barb, to 3/8" transfer hose, to keg quick disconnect. I will typically first connect the QD to the liquid port on the keg which vents the co2 pressure, and co2 purges the transfer line and strainer, pushing any o2 out.
9) once the keg purged of co2, i close the PRV, connect the transfer line to the racking valve, open the PRV on the top of the keg, and open the racking valve to start transferring. Remember the fermenter is constantly under 2-3psi so its a pressure transfer
10) Once i'm at my target fill weight for 4.8-5 gallons, i close the PRV, close the racking arm, disconnect the QD transfer line, then ill put the keg in my keezer, hook it up to around 30psi, fill and purge multiple times with the prv, and then I let it sit at 30psi for 24-36 hours to burst carbonate
11) After i'm done burst carbing, i'll drop the pressure to 12psi, and i'll pull the prv slowly to watch the pressure decrease but never fully empty. I'll pull it until it gets to aroudn 10psi and then you can hear the co2 tank on fillilng back up to that 12psi, so no oxygen should be getting in.

After that, i'm just connecting the liquid out post when its ready to go, and serving.

Where am i going wrong/???

 

[doug293cz]

3a) Purging (pressurize & vent method) at 2 psi is not very effective. Here's a chart that shows residual O2 concentration after different numbers of purge cycles at several different pressures.

​

4) If you are not sucking sanitizer back when you cold crash, then you are sucking air from somewhere. Doesn't matter how slow you go. And silicone tubing has the highest O2 permeability of any of the common tubing materials used in homebrewing.

7) Filling the keg with sanitizer until it comes out the PRV leaves a 3 fl oz air bubble in the lid. There is enough O2 in that volume to kill an NEIPA.

There may be other places in your process that allow O2 ingress, but I am having difficulty visualizing exactly what you are doing in some of your steps.

The best way to purge a keg of O2 is to just put it between the fermenter and the blow-off jar. Can purge the keg to single digit ppb (parts per Billion) O2 levels. Full analysis here.

Brew on

 

[jddevinn]

4) Once ready for cold crash, i either drop the temp in 5 degree increments over a span of 24 hours until i reach the upper 30s. Doing so prevents suckback as no sanitizer makes it up the blowoff tube, therefore no air, unless maybe here is where i'm going wrong, and i'm leaking air in through somewhere else?.
4a) Occasionally if i'm quick crashing, i'll hook my 3" CO2 ball lock plate up to the valve at the top, and put 2-3psi on the fermenter during the crash, and then leave it connected until i transfer.

4a is much better than 4. Silicone has a very height O2 permeability. Even when not cold crashing you should try to remove the blow off tube and go to a spunding valve as soon as possible. Even if the pressure inside the fermenter/tubing is higher than atmospheric the Partial Pressure of O2 will be higher in the atmosphere than the fermenter and O2 will enter regardless of overall pressure.

 

[Iseneye]

Try spunding.

 

[jddevinn]

Also what type of lines are you using for CO2 supply? I had the classic 'red gas lines' and recently switched to EVA barrier tubing as the red line is susceptible to the same O2 ingress due to partial pressure as the silicone tubing (although to a lesser degree.) I'm hoping this will help shelf life of beers I have on tap for long periods (ie an imperial stout might go a week or two without someone pulling a pint)

 

[sicktght311]

1) No spunding since i dont have unitanks
2) Co2 lines are EVA Barrier as well
3) Seems a next step to try to combat this is to ONLY cold crash under positive pressure from a co2 tank


Out of curiosity, whats the process at a small to medium sized brewery. They have unitanks, but that doesnt seem to change the process so long as you're not opening up the fermenter once you hit FG. Unless they're carbonating in the unitank (which i know not all of them do), they still need to transfer to a purged brite tank, and then from a purged brite to a purged keg. How are pro breweries purging their tanks

EDIT - after doing some research on probrewer, it seems a consensus for Brite purging is to use the low and slow method. 4-5psi, pumped in from the bottom, with the top open into a sanitzed blow off bucket, and run that for 45-60 minutes. Or a hybrid method. Low and slow for 25 minutes, then close it up and bring the headspace up to 15psi, dump it down to 1psi, and do that a couple times and then you should be good to go.

4) also instead of trying to co2 purge the keg right before kegging, try connecting my blow off to a sanitized keg's Co2 in, and then put the liquid out to a sanitized blow off jar. This will continuously purge the keg through the process and then close everything up once i hit FG and ready to cold crash.

 

[jddevinn]

I don't have unitanks either, I bought Chronicals back before they even had cooling and made my own cooling tube. I removed the pressure relief that came with the fermenter and added my own set for 3psi and supply CO2 at about 2 psi starting about 2-3 days into fermentation.

 

[couchsending]

What you’re experiencing is settling not oxidation... oxidation does not cause hazy beer to clear.

Stop dry hopping during fermentation. Soft crash your beer and remove yeast before dry hopping. Dry hop at 60* for two days and cold crash. Keep cold for a few days before transferring to your keg.

 

[apache_brew]

What's your typical NEIPA grain bill look like?

 

[Bobby_M]

1) Wort is pumped into Chronical BME fermenter, yeast pitched, blow off cane + Silicone tubing into a jar of sanitizer
2) First Dryhop is typically day 2, and i dont take any O2 precautions here. Pop the lid, throw the hops in
3) 2nd Dryhop is usually either when i still have a few points left, so i quickly open the lid and drop them in.
3a) IF i'm post fermentation, i have a 3" Butterfly valve on top of my Chronical, which I close, remove the blow off cane, put on a 3" sight glass, with a 3" CO2 quick Disconnect plate on top. I fill the sight glass with my hop drop, put the top plate back on, purge with 2psi a number of times, then open the valve to drop the hops. Close the valve, remove the hop dropper, reinstall the blow off tube, slowly open the butterfly to let the excess co2 bubble throught he sanitizer jar, then let it continue to ferment and finish
4) Once ready for cold crash, i either drop the temp in 5 degree increments over a span of 24 hours until i reach the upper 30s. Doing so prevents suckback as no sanitizer makes it up the blowoff tube, therefore no air, unless maybe here is where i'm going wrong, and i'm leaking air in through somewhere else?.
4a) Occasionally if i'm quick crashing, i'll hook my 3" CO2 ball lock plate up to the valve at the top, and put 2-3psi on the fermenter during the crash, and then leave it connected until i transfer.
5) Once its time to transfer, i put the plate on the top, fill the fermenter to 2-3psi, and i'll typically dump trub into a bucket until it starts to run thinner, then i close up the dump port
6) I also dump about a pint worth of beer through the racking port to clean out the racking arm before transfer.
7) To pre-purge my kegs, i fill them to the top with sanitizer, connect co2 at around 15psi, burp the prv to clear the headspace, then i'll connect it to a line on my keezer, and open the tap into a bucket. This clears the keg of sanitizer, clears the serving line of any cleaner or anything left from a previous beer i might have just unhooked, and fills the keg with co2 as its emptying. I would assume this means the keg is fairly well purged of co2 since co2 was continually pushing the sanitizer out.
8) Once the keg is empty and ready, I put together my transfer line. It is a 1.5" Triclamp 100micron inline stainless strainer on the racking valve, to 1.5" Triclamp plate with hose barb, to 3/8" transfer hose, to keg quick disconnect. I will typically first connect the QD to the liquid port on the keg which vents the co2 pressure, and co2 purges the transfer line and strainer, pushing any o2 out.
9) once the keg purged of co2, i close the PRV, connect the transfer line to the racking valve, open the PRV on the top of the keg, and open the racking valve to start transferring. Remember the fermenter is constantly under 2-3psi so its a pressure transfer
10) Once i'm at my target fill weight for 4.8-5 gallons, i close the PRV, close the racking arm, disconnect the QD transfer line, then ill put the keg in my keezer, hook it up to around 30psi, fill and purge multiple times with the prv, and then I let it sit at 30psi for 24-36 hours to burst carbonate
11) After i'm done burst carbing, i'll drop the pressure to 12psi, and i'll pull the prv slowly to watch the pressure decrease but never fully empty. I'll pull it until it gets to aroudn 10psi and then you can hear the co2 tank on fillilng back up to that 12psi, so no oxygen should be getting in.

In order of your numbers.
1. Silicone tubing has a pretty high ingress of oxygen. Change over to PVC tubing on the blowoff.
2. Hook up Co2 to any available port and let it very slowly bubble up through the beer while you quickly remove the 1.5" TC to drop your hops in. Rest the TC fitting on the port on top lightly and let CO2 leak out for 60 seconds before sealing it up again.
3. Same process as #2 but I'd just combine these dryhops into a single dose to avoid opening again.
4. It is impossible to cold crash without SOMETHING ingressing to make up the vacuum (unless the fermenter is soft and can collapse). Yes, you are pulling air in.
4a. Yes, better.
5. 6. no problem.
7. perfect.
8. Probably not an issue but if you leave a few PSI of CO2 in your purged keg, hook up your fermenter side TC on the transfer assembly very look and then connect to the keg out port so that the excess CO2 does a final purge of the assembly and also flushed any air out of the outward side of your racking port valve.
9. Running a grey QD on the gas port with a hose into a bucket of water/starsan is slightly better because a slight amount of oxygen can make it into the PRV even though CO2 is exiting. It's a very small risk though.
All else if fine.

If I had to guess the potential oxygen ingress by worst to least it would be 4, 3, 2, 1. If you are removing the whole large lid when dry hopping rather than just the small TC, it's way worse.

 

[Jim R]

Just to educate myself, why don't you just cold crash in the keg after an earlier transfer and eliminate the largest risk process? A tad more trub in the bottom of the keg won't make any difference.

Also, is the benefit of multiple dry hopping additions and late or post-fermentation dry hopping worth the added oxygen exposure? Are those higher risk steps adding that much to the final beer?

 

[wepeeler]

What you’re experiencing is settling not oxidation... oxidation does not cause hazy beer to clear.

Stop dry hopping during fermentation. Soft crash your beer and remove yeast before dry hopping. Dry hop at 60* for two days and cold crash. Keep cold for a few days before transferring to your keg.

+1

Although I haven't personally experienced oxidation to the extent of some people on here (that I'm aware of), I switched to soft crashing to drop yeast, DHing for a max of 48 hours at 60, then cold crashing before kegging. NEIPAs appear to have more popping hop aroma later in their life, although they don't usually last over 4-5 weeks in the keg. Not sure if it's power of suggestion, but I feel it is making a difference in the quality of beer over time.