Purging

[hjblwme]

So I am a younger brewer (less experienced) and I am going to be attempting my first NEIPA. From reading and attempting to learn I have seen that this is sometimes a very picky style. I have not jumped into kegging. I am planning on bottling this but have heard that oxidation is a potential problem.

So here is my thought. Purge/fill all the bottles with CO2 before beer. Then cap and allow to carbonate. The “method” for this would be something in the manner of sanitize everything, and with dry ice place all bottles into a storage tote and allow the dry ice to completely sublimate. CO2 is heavier then O2 and would push all the O2 out. Then bottle while in the tote and cap.

Thoughts, concerns, ideas.

 

[RPh_Guy]

CO2 is heavier then O2 and would push all the O2 out.

It won't. Gases mix, pretty quickly.

It's certainly possible to bottle without significant oxidation or any artificial CO2.

• Dry hop toward tail end of fermentation.
• Either bottle spund (directly from the fermenter) OR after fermentation completes, prime the fermenter, wait 15 mins, and then bottle directly from there.
• Bottle wand.
• Minimize headspace in the bottles by filling to about 1/4-1/2" from the top.
• Use oxygen-absorbing bottle caps, activated at the time of bottling.

Cheers

 

[Qhrumphf]

If the myth of the CO2 blanket were reality, we'd all be dead.

 

[Vale71]

CO2 is heavier then O2 and would push all the O2 out.

Oxygen is also heavier than nitrogen. By your reasoning we should be breathing pure oxygen with all the nitrogen in the atmposphere hovering well above our heads. This means we would all be breathing pure O2 if it weren't for that deadly bottom layer of CO2 that we need to avoid stepping into at all cost. Must be one of the reasons why penthouse suites are so expensive...

 

[hjblwme]

I understand what you’re saying and it is definitely true that it all mixes. I guess I was over a analyzing things and got kind of wishful. Hoping that if I had enough under the right condition I would be able to do something beneficial.

This is why I ask. You figure that someone else may have tried or heard of the idiot that tried.

 

[McKnuckle]

Even though the gases mix, injecting the bottles with CO2 still reduces the concentration of standing oxygen. Go for it.

 

[Dgallo]

So what you’re proposing is better than nothing. Have your beer warmer that typical room temp at 72/74. Also have your bottles warm, gases have a more difficult time being absorbed at room temps verse cold. I wouldn’t waste the gas to purge the bottles prior to filling them, as stated previously the gases will mix. Just fill the bottle with a bottling wand, then purge the headspace of the bottle the best you can and cap. It’s not perfect but better than if you did nothing. Also, if you can bottle from your primary that’s fermented do it. Racking the beer in the bottling bucket, it typically where the most o2 is picked up

 

[Vale71]

Also have your bottles warm, gases have a more difficult time being absorbed at room temps verse cold.

It's the other way around actually.

 

[Dgallo]

It's the other way around actually.

Gases try to escape solutions as temperature increases.

 

[Vale71]

Yes, and also go into solution equally faster. At equilibrium both rates will cancel each other out no matter what the temperature. However the determining factor for absorption speed is the rate of diffusion in the liquid and that increases with kinetic energy a.k.a. with higher temperature. Gas adsorption is the phenomenom we're discussing, not gas solubility which is a completely different issue.

 

[Vale71]

Now to get back on topic... Large amounts of dry ice will produce large amounts of CO2 gas if they completely sublimate. Playing around with that in an enclosed space might indeed end up sufficiently saturating the room with CO2 that some reduction in beer oxidation might occur. However the very likely reduction in your life expectancy could mean you might not get to enjoy the results. I'm not kidding, CO2 is dangerous and not to be played around with.

 

[Dgallo]

Yes, and also go into solution equally faster. At equilibrium both rates will cancel each other out no matter what the temperature. However the determining factor for absorption speed is the rate of diffusion in the liquid and that increases with kinetic energy a.k.a. with higher temperature. Gas adsorption is the phenomenom we're discussing, not gas solubility which is a completely different issue.

I can’t find any resources that support your claim that higher temperature of a liquid increases the absorption rate of gases. all I keep seeing is along these lines

Do you think you could provide any resources for me?

 

[Vale71]

My bad, I used the term adsorption where I should have used the correct term absorption. Sorry about that. It's easy to get the two mixed up but the former refers to gas adsorption by solids and the latter to gas absorption by liquids.

Here is the quick version in order not to completely hijack the thread. The surface layer (a few atom's depth) of liquid is saturated nearly instantly according to the gas solubility for a given temperature and partial pressure. The gas then needs to diffuse through the liquid for new gas to replace it and so on and so forth until concentration is uniform throughout the liquid and equilibrium between gas phase and solution is reached. This diffusion happens faster the higher the kinetic energy of the gas molecules and hence the higher the temperature.

Since during filling you don't even want to get anywhere close to saturating the beer with O2 but are aiming for much lower levels the solubility of O2 becomes irrelevant. What matters is only the amount of O2 that will be picked up during the (hopefully brief) time that the beer has contact with residual O2. One of the ways to mitigate O2 pickup is therefore to keep the beer as cold as possible so that diffusion proceeds at the slowest possible rate. Ideally beer should be as close to freezing temperature as possible for maximum mitigation.

The other two mitigation factors are reduction of partial pressure of O2 through effective purging and reduction of contact surface between beer and gas phase, for example through use of a dip tube in a counterpressure bottle filler or filling over the "beer out" port in a keg insted of just letting the beer dribble over the package's inner surface.

P.S. Gas absorption is exotermic as well but we can just ignore that fact. At the rate beer absorbs gas even when force carbonating you won't see a noticeable rise in temperature just because of that. Diffusion speed is really the only relevant factor in this context.

 

[RPh_Guy]

Ideally beer should be as close to freezing temperature as possible for maximum mitigation.

This is ignoring one of our most valuable assets for fighting oxygen exposure -- the yeast.

When bottling we want the yeast to be as active as possible so they consume the oxygen, hence my recommendation for spunding. Cold temperature would do more harm than good in our situation.

 

[balrog]

And doesn't some of the O2 get used by the yeast in the bottle during the fermentation of the priming sugar, or has the oxidation of malt and hop "-oids" already happened by then?

[Edit: I type to slowly for RPh]

 

[Vale71]

Yeast scavenging is wildly overrated. In any case, if you effectively prevent oxygen pickup to below critical levels you won't need it anyway. Besides that, you should have enough healthy yeast that refermentation proceeds unhindered once the bottles warm up to room temperature again. And if you're spunding you'll be counterpressure filling so there will be no priming sugar and no bottle fermentation.

 

[Vale71]

And doesn't some of the O2 get used by the yeast in the bottle during the fermentation of the priming sugar, or has the oxidation of malt and hop "-oids" already happened by then?

[Edit: I type to slowly for RPh]

Some but most definitely not all. And any oxygen that does get into the beer can either be absorbed by yeast or oxidize the beer, there really is no preference. Oxygen is extremely reactive and will react with anything it can without targeting yeast over everything else.

 

[RPh_Guy]

Good thing we're not talking about counterpressure filling, but rather bottling uncarbonated beer.

Yeast oxygen scavenging happens quite rapidly when the yeast are active.

Oxygen is extremely reactive and will react with anything it can without targeting yeast over everything else.

If this were true we wouldn't be aerating the wort before pitching. In fact if the reactions happened so fast, the yeast wouldn't even have access to the DO because it would be reacting with the wort.

We know oxidation of wort components (via Reactive Oxygen Species, ROS) doesn't happen instantly at fermentation temperatures, and we also know that yeast do rapidly consume DO (not just ROS) at fermentation temperatures.
So, yes, yeast oxygen scavenging is hugely advantageous, in bottle carbonated beer.

 

[balrog]

For now, I'll just stick to ferm-n-serve-float-dip-tube-keg for the very very few hoppy batches I make.

 

[Vale71]

If this were true we wouldn't be aerating the wort before pitching.

Wort and beer are completely different things. Even with bottle refermentation you're still bottling fully fermented beer. Yeast oxygen scavenging in bottle fermented beers is only modestly effective. If this weren't the case then commercial operations that still do bottle refermentation (think traditional wheat beer in Germany) wouldn't bother with counterpressure filling to the same low O2 standards as normal beer, would they? Fact is, they do, although obviously you don't need as much pressure as with fully carbed beer to prevent foaming. So counterpressure filling is not really just for fully carbonated beer after all.

 

[Brooothru]

This is ignoring one of our most valuable assets for fighting oxygen exposure -- the yeast.

When bottling we want the yeast to be as active as possible so they consume the oxygen, hence my recommendation for spunding. Cold temperature would do more harm than good in our situation.

You raised an interesting question for me. I haven't primed and bottled in quite a few years. I mostly keg, and if I want some bottles, use a counter-pressure bottler to fill them and cap on the foam. I also make quite a bit of wine and started using a vacuum bottle filler about 10 years ago. I never even considered using it for beer bottling, since the CO2 would come gushing out of solution under a partial vacuum. But if I used carbonation drops or glucose tablets I could vacuum bottle uncarbonated beer sans oxygen into the bottle without purging, then cap and condition.

Now instead of brewing beer that tastes like sauvignon blanc, I can have wine that tastes like beer!

Brooo Brother

 

[Vale71]

Not to rain on your parade but the vacuum those systems work with is quite puny, there is still plenty of oxygen left in the bottle. Besides even unspunded beer is not really uncarbonated. If exposed to a vacuum it will foam like there is no tomorrow.

 

[RPh_Guy]

If this weren't the case then commercial operations that still do bottle refermentation (think traditional wheat beer in Germany) wouldn't bother with counterpressure filling to the same low O2 standards as normal beer, would they?

Lower oxygen exposure is better because some DO/ROS does react with the beer components, as you're correctly pointing out.
The less oxygen that is introduced, the faster the yeast will consume all of DO, and the less ROS that will react with the other beer molecules.
More oxygen exposure is bad, but the yeast can still be a huge help because yeast DO scavenging is a faster chemical process thanks to their enzymes.

So counterpressure filling is not really just for fully carbonated beer after all.

I've never had problems with excessive foaming when bottling through a regular bottling wand regardless of what temperature the beer is, so I don't know what point you're trying to make with this.

vacuum bottle filler

I have to agree with @Vale71 in his assessment.

 

[Brooothru]

Not to rain on your parade but the vacuum those systems work with is quite puny, there is still plenty of oxygen left in the bottle. Besides even unspunded beer is not really uncarbonated. If exposed to a vacuum it will foam like there is no tomorrow.

Yeah, I see your point.

 

[Dgallo]

Wrong thread

 

[Vale71]

Wrong thread?