The definitive NEIPA bottling experiment!

[beerhenry]

OK so a few months ago I wrote in this forum about the potential effect of purging the headspace of a NEIPA with CO2 in order to prolong the shelf life of the beer. And while I enjoyed reading all the replies it all got a bit speculative and I didn't feel I had anything to add by prolonging the discussion. So I never replied...

Instead I decided to do some science!

AIM:

To investigate the effect of headspace size and CO2 purging in the bottling process.

METHOD:

I brewed a 5% NEIPA with 50% Pale Ale, 20 % Munich, 10% Wheat, 10% Oats, 10 % DME. Everything went into the primary with some Opshaug from a farm in Norway (Norwegian farmhouse kveik brewers yeast online store | Kveikshop). Dry hopped for 5 days and cold crashed with a CO2 filled bag covering the airlock.

I bottled directly from the primary after a couple of weeks in total with a bottle wand. I used sugar cubes as my priming sugar in every bottle.

The bottles were filled in three different ways.

1. Filled with the bottle wand leaving a normal headspace when removed
2. Filled with the bottle wand, then continued filling with bottle wand removed until about 10mm from the bottom of the cap
3. Filled to around 10mm from the bottom of the cap and purged with CO2.

Different bottling methods


The purging method involved using small CO2 cartridges and a CO2-valve used for bike tires with a small tube attached. I blew some CO2 into the liquid (trying to create bubbles) and capped within a few seconds.

I drank most of the beer but left 3 bottles in a fridge att 2 C for about 4 months

The final product!


RESULTS:

Colour: The differences in colour between the headspace beer and the beers without headspace was obvious. The difference between the purged and non-purged variants was more subtle. All 3 people in the testing panel chose the CO2-purged beer as the brightest

CO2 purged beer vs headspace beer after 4 months

Headspace vs CO2 purge vs No headspace (no CO2)


Aroma: Blind testing was pretty inconclusive here. Each beer had som hop character left but the difference wasn't too dramatic. Maybe we just suck at smelling?

Taste: The panel agreed that the beers without headspace had much more fruity, juicy notes. The beer with headspace was even described as being more bitter than the others.


CONCLUSION:

Minimising headspace and purging with CO2 is an effective way of prolonging the life of NEIPA. In the absence of CO2, minimising headspace works on its own, though to a lesser degree.

 

[IslandLizard]

Thank you for the follow up and posting the results of your NEIPA bottling experiment.

Glad you're OK!
Some of us may have been worried what happened to you. The thread you started then, and are referring to, was the one and only post you ever made here, even though there were 128 replies to it!

For those curious, here's the thread the OP started on January 12, 2021, over 8 months ago, and the discussion that followed:
https://www.homebrewtalk.com/threads/purging-headspace-when-bottling.688687/

 

[BrewnWKopperKat]

Thank you @beerhenry for additional confirmation that there are ways to bottle hoppy beers.

And a "shout-out" to @Taket_al_Tauro who started a topic back in 2018 on this idea.

 

[day_trippr]

So the OP was seriously focused! I'm good with that

But, let's face it, "O2 is bad for new england style ipas" is not going to get the media on high alert

Cheers!

 

[Taket_al_Tauro]

And a "shout-out" to @Taket_al_Tauro who started a topic back in 2018 on this idea.

Thanks!
However I'm certainly not taking credit for this idea, as it was nothing new even back in 2018. I had seen other guys post about something very similar previously, both here and elsewhere. But probably this topic did not attract much attention back then.
Things have changed since the NEIPA craze and everyone freaking out about O2 ;-)

But I'm glad to see other people confirm that these approaches are working, be it purging headspaces, minimizing it, and/or the ascorbic acid thing...

 

[Miraculix]

OK so a few months ago I wrote in this forum about the potential effect of purging the headspace of a NEIPA with CO2 in order to prolong the shelf life of the beer. And while I enjoyed reading all the replies it all got a bit speculative and I didn't feel I had anything to add by prolonging the discussion. So I never replied...

Instead I decided to do some science!

AIM:

To investigate the effect of headspace size and CO2 purging in the bottling process.

METHOD:

I brewed a 5% NEIPA with 50% Pale Ale, 20 % Munich, 10% Wheat, 10% Oats, 10 % DME. Everything went into the primary with some Opshaug from a farm in Norway (Norwegian farmhouse kveik brewers yeast online store | Kveikshop). Dry hopped for 5 days and cold crashed with a CO2 filled bag covering the airlock.

I bottled directly from the primary after a couple of weeks in total with a bottle wand. I used sugar cubes as my priming sugar in every bottle.

The bottles were filled in three different ways.

1. Filled with the bottle wand leaving a normal headspace when removed
2. Filled with the bottle wand, then continued filling with bottle wand removed until about 10mm from the bottom of the cap
3. Filled to around 10mm from the bottom of the cap and purged with CO2.



View attachment 742585
Different bottling methods


The purging method involved using small CO2 cartridges and a CO2-valve used for bike tires with a small tube attached. I blew some CO2 into the liquid (trying to create bubbles) and capped within a few seconds.

I drank most of the beer but left 3 bottles in a fridge att 2 C for about 4 months

View attachment 742583
The final product!


RESULTS:

Colour: The differences in colour between the headspace beer and the beers without headspace was obvious. The difference between the purged and non-purged variants was more subtle. All 3 people in the testing panel chose the CO2-purged beer as the brightest
View attachment 742581
CO2 purged beer vs headspace beer after 4 months

View attachment 742588
Headspace vs CO2 purge vs No headspace (no CO2)


Aroma: Blind testing was pretty inconclusive here. Each beer had som hop character left but the difference wasn't too dramatic. Maybe we just suck at smelling?

Taste: The panel agreed that the beers without headspace had much more fruity, juicy notes. The beer with headspace was even described as being more bitter than the others.


CONCLUSION:

Minimising headspace and purging with CO2 is an effective way of prolonging the life of NEIPA. In the absence of CO2, minimising headspace works on its own, though to a lesser degree.

View attachment 742590

Thank you!

Can you please elaborate the construction of your co2 bubbler? I have no idea how to create one...

 

[beerhenry]

Thank you!

Can you please elaborate the construction of your co2 bubbler? I have no idea how to create one...

Its actually just an inflator thats used for pumping tires with CO2 cartridges when your out riding. There’s a knob on the side that allows you to open and restrict the airflow.

I removed the valve from an old inner tube, cut off the rubber and attached som 9mm tubing onto it. Put them together and purge away!

 

[Miraculix]

Its actually just an inflator thats used for pumping tires with CO2 cartridges when your out riding. There’s a knob on the side that allows you to open and restrict the airflow.

I removed the valve from an old inner tube, cut off the rubber and attached som 9mm tubing onto it. Put them together and purge away!

CO2 tire pump? Wow, didn't know that such a thing exists

 

[BasementArtie]

This what I'm finding in my bottling NEIPA and hazy beers experiments (if I can call my lackluster attempts that)

https://www.homebrewtalk.com/threads/bottling-a-triple-neipa.692760/page-2#post-9164242
https://www.homebrewtalk.com/threads/bottling-a-hazy-session-ipa.695287/#post-9164231
I didn't use a CO2 overfill variable however I did notice that the bottles filled normally in the session experiment are starting to taste more bitter and darkening in colour. The overfilled bottles are slightly fresher tasting and definitely have more hop zing when opened.

 

[BasementArtie]

Its actually just an inflator thats used for pumping tires with CO2 cartridges when your out riding. There’s a knob on the side that allows you to open and restrict the airflow.

I removed the valve from an old inner tube, cut off the rubber and attached som 9mm tubing onto it. Put them together and purge away!

As a cyclist I have plenty of these knocking around and have never thought about using it.

Can I ask how many bottles you can get out of one small bike CO2 cannister.

 

[beerhenry]

As a cyclist I have plenty of these knocking around and have never thought about using it.

Can I ask how many bottles you can get out of one small bike CO2 cannister.

I only bottled 10 or so beers with CO2 but wasn’t even close to using up a cannister. I imagine one would last at least 30-40 beers if you can lower the flow rate enough so that it bubbles lightly.

 

[mendelec]

I just bottled a NEIPA a week ago and took an extensive list of measures to try to reduce the oxidation after seeing all the traffic discussing the issue. Flushed the bottling bucket with CO2 (3/8" hose through a 3/8" hole drilled into the lid of the bottling bucket), did a closed transfer under positive pressure with CO2 and kept a continuous flow of CO2 going through the hose during the entire process. Used 0.25 g SMB and 3.0g ascorbic acid as antioxidents, based on some other threads and research. Flushed the bottles with CO2 beforehand and then immediately laid a cap on top to (hopefully) contain the gas somewhat until filling the bottle. It seemed to go according to plan, but was enough of a PIA that it was likely the last time I bottle a NEIPA. I'm now looking into kegging.
-Anyway, when it was all done, I stepped back and had the forehead slap moment of realizing that I hadn't flushed the headspace after filling the bottles. Oops.
Cracked into the first bottle a week after bottling (I'm an impatient SOB) and was pretty happy with the result, though I was hoping for a more intense hop aroma (need to work on my whirlpool). No sign of oxidation, which surprised me some, since I'd kicked over that bottle just after capping it, so that headspace of air was very effectively and rapidly mixed in. So, maybe all those other measures I took helped. Still, I'll be drinking that other bottle I kicked over very soon and the rest of the batch won't be given a chance to get 4 months old like in the OP's test.

 

[ljm]

Back in May 2017 my son asked me make beer for his wedding in mid-October. Silly me, I spent the summer making 9 different beers of 2 cases for each - including a NEIPA. I had bottled a NEIPA earlier in the year with no special precautions and it started losing its fruitiness at about 1 month. So this time I took some extra paranoid measures to exclude oxygen. They relied on the fact that CO2 molecules are heavier than O2 molecules. A concentrated dose of CO2 pushes air out of any container. All CO2 was supplied with my kegging tank.
- Tubing was run from the fermenter into the bottom of the bucket, minimizing O2 mixing. (Normal operating procedure.)
- The bottling bucket was purged with CO2, keeping the lid on loosely to avoid drafts.
- The headspace of the fermenter was also purged and as it drained, more CO2 was added. Again the lid was loosely placed.
- During bottling, the BB headspace was occasionally topped up with CO2.
- The bottles were all purged with CO2 followed by a cap placed on top - again to avoid drafts.
Bottling was one 1 month before the celebration. The NEIPA was first to disappear at the party, but my son spirited away several bottles for safe-keeping. About 4 months after the wedding he surprised me with one of the bottles. Holy ****! It was just as juicy as it was after sitting in the bottle for only 2 weeks. He was still enjoying the last bottle 7 months after bottling.
So it is a PITA, but may occasionally be worth it. (I find a lot of commercial NEIPAs these days to be pretty blah.) No need to pouch the bubbler: it is after all expelling air and excess carbon dioxide. Just remember, absent drafts, CO2 sinks to displace air. I am pretty careful with all IPAs, but not neccesarily this obsessive. A few judicious shots of CO2 in the process helps tremendously. And all my bottled IPAs are gone after a couple months anyway.

 

[Miraculix]

Back in May 2017 my son asked me make beer for his wedding in mid-October. Silly me, I spent the summer making 9 different beers of 2 cases for each - including a NEIPA. I had bottled a NEIPA earlier in the year with no special precautions and it started losing its fruitiness at about 1 month. So this time I took some extra paranoid measures to exclude oxygen. They relied on the fact that CO2 molecules are heavier than O2 molecules. A concentrated dose of CO2 pushes air out of any container. All CO2 was supplied with my kegging tank.
- Tubing was run from the fermenter into the bottom of the bucket, minimizing O2 mixing. (Normal operating procedure.)
- The bottling bucket was purged with CO2, keeping the lid on loosely to avoid drafts.
- The headspace of the fermenter was also purged and as it drained, more CO2 was added. Again the lid was loosely placed.
- During bottling, the BB headspace was occasionally topped up with CO2.
- The bottles were all purged with CO2 followed by a cap placed on top - again to avoid drafts.
Bottling was one 1 month before the celebration. The NEIPA was first to disappear at the party, but my son spirited away several bottles for safe-keeping. About 4 months after the wedding he surprised me with one of the bottles. Holy ****! It was just as juicy as it was after sitting in the bottle for only 2 weeks. He was still enjoying the last bottle 7 months after bottling.
So it is a PITA, but may occasionally be worth it. (I find a lot of commercial NEIPAs these days to be pretty blah.) No need to pouch the bubbler: it is after all expelling air and excess carbon dioxide. Just remember, absent drafts, CO2 sinks to displace air. I am pretty careful with all IPAs, but not neccesarily this obsessive. A few judicious shots of CO2 in the process helps tremendously. And all my bottled IPAs are gone after a couple months anyway.

If Co2 would truely sink to replace air, we´d be all dead by now.

 

[BrewnWKopperKat]

He was still enjoying the last bottle 7 months after bottling.

So over 200 days after bottling. Well done!!

Maybe if readers focus on the technique, rather than an incorrect explanation, we can continue move the discussion on bottling techniques forward.

 

[ljm]

If Co2 would truely sink to replace air, we´d be all dead by now.

Joking, right?

 

[BrewnWKopperKat]

Joking, right?

Probably not. See CO2 blanket poll .

As a reminder to readers: what @Ijm described is a process for good beer in a bottle after 200+ days.

 

[ljm]

As to a CO2 danger at ground level, oxygen is about 21% of the atmosphere and nitrogen 78%. That leaves 1% for things like CO2 which is present at about 400ppm. That means that if you count a million gas particles, 400 of them would be CO2. So even if all CO2 suddenly sunk to ground level (which might be a good thing for global warming), the atmosphere is constantly churning and it couldn't stay there.

Yes, gases do mix, but a decent CO2 blanket in brewing can indeed be made with judicious introduction of the gas and minimizing air/CO2 circulation. This is what is happening in your fermenter. CO2 is coming from the beer surface into the headspace. To maintain constant pressure, if gases enter the fermenter gases must also leave through the bubbler. Those gases are initially nitrogen and oxygen. As fermentation proceeds, the headspace is increasingly CO2 because it is the primary gas entering the system. Air is not very succesfully penetrating the airlock back into headspace. That is why it is called an airlock.
"Blanket" may be a misleading word when it comes to gases. It is a permeable blanket, but if CO2 reaches a good percentage of headspace molecules you have a good enough brewing blanket. If you are trying to reduce O2 in the headspace of a bottling bucket, a couple of squirts from the tank isn't going to do it. You have to think in terms of slowly introducing CO2 near the surface of the beer to minimize stirring the gases and make the most likely contact of beer with CO2, not O2. You can't get rid of oxygen but you can certainly reduce its effects on your beer.

 

[Miraculix]

As to a CO2 danger at ground level, oxygen is about 21% of the atmosphere and nitrogen 78%. That leaves 1% for things like CO2 which is present at about 400ppm. That means that if you count a million gas particles, 400 of them would be CO2. So even if all CO2 suddenly sunk to ground level (which might be a good thing for global warming), the atmosphere is constantly churning and it couldn't stay there.

Yes, gases do mix, but a decent CO2 blanket in brewing can indeed be made with judicious introduction of the gas and minimizing air/CO2 circulation. This is what is happening in your fermenter. CO2 is coming from the beer surface into the headspace. To maintain constant pressure, if gases enter the fermenter gases must also leave through the bubbler. Those gases are initially nitrogen and oxygen. As fermentation proceeds, the headspace is increasingly CO2 because it is the primary gas entering the system. Air is not very succesfully penetrating the airlock back into headspace. That is why it is called an airlock.
"Blanket" may be a misleading word when it comes to gases. It is a permeable blanket, but if CO2 reaches a good percentage of headspace molecules you have a good enough brewing blanket. If you are trying to reduce O2 in the headspace of a bottling bucket, a couple of squirts from the tank isn't going to do it. You have to think in terms of slowly introducing CO2 near the surface of the beer to minimize stirring the gases and make the most likely contact of beer with CO2, not O2. You can't get rid of oxygen but you can certainly reduce its effects on your beer.

There's a huge difference between a co2 blanket (a myth, not existing) and replacing the air within a closed container with co2.

The gases in the container will completely mix after some time, so all the oxygen that has been left will have contact with the beer. If you managed to get enough of it replaced by the introduced volume of co2, then that's good. If not, it's not good. It's that simple, no blanket.

 

[BrewnWKopperKat]

so maybe, in the end, it all comes down to this

​

(and this time, the blue items are Co2).

 

[ljm]

Exactly!

 

[vin8n1]

beerhenry, i love the experiment! Just by the way your glasses are dirty. Often the dishwasher isnt enough to get them clean. you can tell by all the bubbles on the walls of your glass. The bubbles are caused by nucleation points (aka gunk stuck to the side of the glass). Cheers!