Cold crash and oxidation

[STMF]

It says exactly that if a gas it's heavier than another it takes a lot of time to mix

In the clip, the Br2 and "air" is fully mixed after just half an hour. Br2 is about 4 times as heavy as C02.

 

[marchio-93]

In the clip, the Br2 and "air" is fully mixed after just half an hour. Br2 is about 4 times as heavy as C02.

Yes, and someone here said that O2 and Co2 mix IMMEDIATELY because the particles go 138377 km/h, when we have a bucket FULL of Co2 and an amount of O2 that comes in of what, some mL?

 

[STMF]

Yes, and someone here said that O2 and Co2 mix IMMEDIATELY because the particles go 138377 km/h, when we have a bucket FULL of Co2 and an amount of O2 that comes in of what, some mL?

Well, its complex. When you open the lid on a bucket, there is no way you can do so carefully that it will not stir up the CO2.
One way to explain it is to think of gases as liquid. Imagine that you have a bucket with a liquid (like milk), a little heavier than water. You put the bucket fully submerged in water and you open the lid. It is quite clear that imediatly the milkin the bucket will go into the water and water will mix with the milk in the bucket.

How much? It depends ofcourse but you will never be able to open the bucket without instant mixing occuring.

 

[Vale71]

Yes, and someone here said that O2 and Co2 mix IMMEDIATELY because the particles go 138377 km/h, when we have a bucket FULL of Co2 and an amount of O2 that comes in of what, some mL?

It doesn't matter whether it takes seconds or minutes for the mixing to be complete since your beer will be in the fermenter for days and will be totally exposed to any oxygen that comes into the fermenter.
As for the amount, if you keep your beer refrigerated for longer than a few minutes it will actually start absorbing CO2 from the headspace and that CO2 will have to be replaced by more air or your bucket would implode. That means a lot more than a few milliliters of air will be gettting in by the time you're finally bottling your beer.

P.S. At 25°C a molecule of CO2 actually travels at 1480 km/h on average so it's actually supersonic. If it weren't for the constant molecular collisions the resulting shock wave would knock you over.

 

[marchio-93]

Well, its complex. When you open the lid on a bucket, there is no way you can do so carefully that it will not stir up the CO2.
One way to explain it is to think of gases as liquid. Imagine that you have a bucket with a liquid (like milk), a little heavier than water. You put the bucket fully submerged in water and you open the lid. It is quite clear that imediatly the milkin the bucket will go into the water and water will mix with the milk in the bucket.

How much? It depends ofcourse but you will never be able to open the bucket without instant mixing occuring.

But I've not open my bucket [emoji848]

 

[marchio-93]

It doesn't matter whether it takes seconds or minutes for the mixing to be complete since your beer will be in the fermenter for days and will be totally exposed to any oxygen that comes into the fermenter.
As for the amount, if you keep your beer refrigerated for longer than a few minutes it will actually start absorbing CO2 from the headspace and that CO2 will have to be replaced by more air or your bucket would implode. That means a lot more than a few milliliters of air will be gettting in by the time you're finally bottling your beer.

P.S. At 25°C a molecule of CO2 actually travels at 1480 km/h on average so it's actually supersonic. If it weren't for the constant molecular collisions the resulting shock wave would knock you over.

They can run at the light speed for me, the video show how slow two different weight gas mix, when someone said it happens in a fraction of a second, and it's wrong.

Can you explain me why there is not a single bubble in the airlock, when you say are coming in at least 10 litres of air? Without any implosion?

 

[Vale71]

One can't help but wonder about people who come here asking for advice and then attack the people who don't tell them what they want to hear...

 

[marchio-93]

One can't help but wonder about people who come here asking for advice and then attack the people who don't tell them what they want to hear...

I can not hear people say "you completely wrong" or things like that, to other people, as they have the truth in their hand, when their is nothing more approximate than our hobby. Maybe to justify thousands of dollars' worth of equipment, and then repeat the same sentence without giving a real scientific answer

 

[yoop89]

I can not hear people say "you completely wrong" or things like that, to other people, as they have the truth in their hand, when their is nothing more approximate than our hobby. Maybe to justify thousands of dollars' worth of equipment, and then repeat the same sentence without giving a real scientific answer

Maybe just take a minute to step back and re read this whole thread with a clear mind? Nobody is saying you're wrong or your beer is now pure oxygen. You started this thread with a question to whether or not cold crashing can cause oxidation and the simple answer is yes, without some sort of protection. Everyones responses are just in response to your questions that arise and others. A lot of good information above, take it or leave it?

BTW, simple cold crash device, $2 mylar balloon(happy birthday, get well soon, etc.) and some tubing added towards the end of fermentation will provide enough clean CO2 for you to cold crash.

Edit to add everyones favorite "scientists"
http://brulosophy.com/2018/05/10/7-methods-for-reducing-cold-side-oxidation-when-brewing-beer/

 

[marchio-93]

Maybe just take a minute to step back and re read this whole thread with a clear mind? Nobody is saying you're wrong or your beer is now pure oxygen. You started this thread with a question to whether or not cold crashing can cause oxidation and the simple answer is yes, without some sort of protection. Everyones responses are just in response to your questions that arise and others. A lot of good information above, take it or leave it?

BTW, simple cold crash device, $2 mylar balloon(happy birthday, get well soon, etc.) and some tubing added towards the end of fermentation will provide enough clean CO2 for you to cold crash.

Edit to add everyones favorite "scientists"
http://brulosophy.com/2018/05/10/7-methods-for-reducing-cold-side-oxidation-when-brewing-beer/

So, for you, "you are completely wrong" it's a normal explanation in a constructive conversation. Then okay

 

[archthered]

My 2 cents. You will definitely get some oxidation, if you are careful then the amounts will be low and likely make little immediate difference. However oxidization results in premature staling and the beer will not age as well as it could. I personally cold crash alot and have yet to notice any real issues with oxidization flavors, however I have not done any sensory panel stuff with oxidization and may not notice it at low levels, additionally I typically go through my beer fairly quickly so I usually don't have to worry about how well it ages, unless I'm doing a beer that needs to age. In short you are not wrong but they aren't wrong either, you will certainly get some oxygen in and it will alter the beer, but will it be enough that you personally should worry? Only you can tell, I'd try your beer and see what you think, think about the potential for oxidization flavors as you taste it and decide what you want to do in the future. Until then RDWHAHB

 

[yoop89]

With all due respect you are completely wrong on this one. Gasses mix

So, for you, "you are completely wrong" it's a normal explanation in a constructive conversation. Then okay

If you are referring to that post then yes, I believe that is constructive conversation. When someone says something that is blatantly incorrect I believe it is important to correct. This is a public forum that many people come to for information and if someone posts something that is wrong its important that it is corrected so others don't take it for truth.

 

[marchio-93]

If you are referring to that post then yes, I believe that is constructive conversation. When someone says something that is blatantly incorrect I believe it is important to correct. This is a public forum that many people come to for information and if someone posts something that is wrong its important that it is corrected so others don't take it for truth.

This sentence has been repeated a lot of time, and referring to something that is not incorrect at all. As someone said I pick up several litres of O2 but can not answer to the question "why not a single bubble in the airlock". So because it is a forum, maybe someone can read it and hear different opinion, and maybe DISCUSS, and don't put sentence as the truth. But if you want we can call this forum "ask to God the answer" and then just wait for your sentences.

Ps: I took a Belgian IPA to a competition, which was transfered and cold crashed for a week. It arrived on the podium, over counter-pressure beers. Maybe today send an email to the judges explaining why they are completely wrong

Pps: the beer was 4 months

 

[marchio-93]

My 2 cents. You will definitely get some oxidation, if you are careful then the amounts will be low and likely make little immediate difference. However oxidization results in premature staling and the beer will not age as well as it could. I personally cold crash alot and have yet to notice any real issues with oxidization flavors, however I have not done any sensory panel stuff with oxidization and may not notice it at low levels, additionally I typically go through my beer fairly quickly so I usually don't have to worry about how well it ages, unless I'm doing a beer that needs to age. In short you are not wrong but they aren't wrong either, you will certainly get some oxygen in and it will alter the beer, but will it be enough that you personally should worry? Only you can tell, I'd try your beer and see what you think, think about the potential for oxidization flavors as you taste it and decide what you want to do in the future. Until then RDWHAHB

Of course I will use the measures for the next cold crashes, thanks to the people who responded and gave me advice. I am very sorry for those who shoot sentences convinced that they have the truth in hand and have no intention of confronting each other

 

[yoop89]

Not sure what you're meaning by "not a single bubble in the airlock" but in your picture you can see all the liquid on the fermenter side of the airlock showing a vacuum has formed. Therefore, you possible got some air inside your fermenter. Whether or not you saw it happen is what it is. Congrats on the podium finish! Not a lot of people are dedicated enough to enter competitions.

Like others have said some people are super sensitive to oxidation flavors and some are not, some beers are more sensitive to O2 exposure, some less. Just take the last posters advice. RDWHAHB, we are all here for the same reason. Beer, right?

 

[marchio-93]

Not sure what you're meaning by "not a single bubble in the airlock" but in your picture you can see all the liquid on the fermenter side of the airlock showing a vacuum has formed. Therefore, you possible got some air inside your fermenter. Whether or not you saw it happen is what it is. Congrats on the podium finish! Not a lot of people are dedicated enough to enter competitions.

Like others have said some people are super sensitive to oxidation flavors and some are not, some beers are more sensitive to O2 exposure, some less. Just take the last posters advice. RDWHAHB

But when you ask to describe "oxidation", except for the heavily oxidated, thay can't! They give this name to anything is wrong with the beer as literally said by someone in this post. Excluding all the factors that come in brewing. That's incredible

 

[mkopec1]

Here is a link to anyone who wants to see for themself how gases mix.

Thanks for this. This basically proves that weve been sold a bunch of bullcrap about blankets of Co2 gently massaging our beer at all times, like I and im sure many of us have been taught by other homebrewers and even books and magazines.

 

[yoop89]

 

[lump42]

Thanks for this. This basically proves that weve been sold a bunch of bullcrap about blankets of Co2 gently massaging our beer at all times, like I and im sure many of us have been taught by other homebrewers and even books and magazines.

Yes, the 'co2 blanket' is an old brewer's tale. If it was true, we'd all be sitting in a sea of nitrogen since it is heavier than oxygen.

The counter point to the oxidation issue is that if you enjoy your beer the way you are brewing it now than it's the amount of oxidation isn't a flaw. I would still try and split a batch, half closed transfer and the other open, to see if there is a preference. That preference may change depending on style too.

 

[mediant]

This sentence has been repeated a lot of time, and referring to something that is not incorrect at all. As someone said I pick up several litres of O2 but can not answer to the question "why not a single bubble in the airlock".

Most likely you don't see the bubbles going back because it happens slowly behind the chiller's closed door.
I connect a urine bladder between the fermenter and the airlock to harvest CO2 for cold crash, and it decreases by 1-1.5 liters approximately while cold crashing, so I guess that's roughly the volume being sucked in.

 

[mkopec1]

Yes, the 'co2 blanket' is an old brewer's tale. If it was true, we'd all be sitting in a sea of nitrogen since it is heavier than oxygen.

The counter point to the oxidation issue is that if you enjoy your beer the way you are brewing it now than it's the amount of oxidation isn't a flaw. I would still try and split a batch, half closed transfer and the other open, to see if there is a preference. That preference may change depending on style too.

Problem with this is I dont have a sealed fermentor. Still using old school carboys I purchased in like the 90s. But even if I got one of those fermzillas or whatever how would you purge the O2 from the headspace on the fermentor? Even when the yeast is doing its thing and making Co2, there is still going to be O2 in the head space of the fermentor. Some of it will be pushed out by the spunding valve, but there will still be O2 in there, right? Or does the yeast eat up all the available O2, even in the head space?

 

[bob1852]

I think that's a bit exaggerated and simplistic, and of course not "the best way to discribe oxidation" but.. Okay

Why are you so defensive?

 

[lump42]

Problem with this is I dont have a sealed fermentor. Still using old school carboys I purchased in like the 90s. But even if I got one of those fermzillas or whatever how would you purge the O2 from the headspace on the fermentor? Even when the yeast is doing its thing and making Co2, there is still going to be O2 in the head space of the fermentor. Some of it will be pushed out by the spunding valve, but there will still be O2 in there, right? Or does the yeast eat up all the available O2, even in the head space?

You don't need a new fermentor. One of the orange carboy caps would be a cheap solution. The racking cane goes through one hole, co2 into the other.

The headspace almost entirely co2 at the tail-end of fermentation. The yeast will scavenge oxygen during their active phase. O2 in the lag phase is usually not an issue. The amount of co2 given off during the active fermentation will expel most of the rest. If you are using a stopper and airlock on a glass carboy that will keep o2 ingress into the headspace.

 

[lump42]

Problem with this is I dont have a sealed fermentor. Still using old school carboys I purchased in like the 90s. But even if I got one of those fermzillas or whatever how would you purge the O2 from the headspace on the fermentor? Even when the yeast is doing its thing and making Co2, there is still going to be O2 in the head space of the fermentor. Some of it will be pushed out by the spunding valve, but there will still be O2 in there, right? Or does the yeast eat up all the available O2, even in the head space?

Here's a video that lays out the steps. If you have a draft system, there wouldn't be much investment.

 

[marchio-93]

You don't need a new fermentor. One of the orange carboy caps would be a cheap solution. The racking cane goes through one hole, co2 into the other.

.

Okay thanks I've seen the video now. But what about a plastic bucket?

 

[mkopec1]

Hmm, this is giving me some ideas, guys, thanks. I wonder if I could make something like this to fit inside the carboy, maybe a ping pong ball? This would make the system even better by siphoning off the beer from the top not to disturb the trub and yeast on the bottom..

https://kegfactory.com/products/torpedo-keg-buoy™-floating-dip-tube

Or maybe its just time to retire the old tired glass carboys, lol.

 

[McKnuckle]

""why not a single bubble in the airlock"

During fermentation, CO2 inside the bucket is pushing outward through the airlock under pressure, venting to a practically infinite space at atmospheric pressure. The force from within the bucket causes visible and obvious bubbles in the airlock as the CO2 escapes. When the pressure equalizes between the bucket and the surrounding air, bubbling ceases.

During cold crash, an infinite volume of air at atmospheric pressure is drawn into a small volume of space (inside the bucket) by a vacuum, which it rapidly fills, causing only a few quick bubbles and then no more. Perhaps you just weren't watching when it happened?

 

[marchio-93]

During cold crash, an infinite volume of air at atmospheric pressure is drawn into a small volume of space (inside the bucket) by a vacuum, which it rapidly fills, causing only a few quick bubbles and then no more. Perhaps you just weren't watching when it happened?

Well I've followed all the fermentation, and I could clearly hear the bubbles of the Co2. As you say that the space is rapidly filled, so while I chill the fermenter I should hear or see this clear bubbling. This make me think that the only reason I don't hear or see any bubble is because the amount of O2 gone through the airlock is very little, and so I can not hear it. The amount of Co2 that get out during fermentation is not very huge, but you hear that sound for days.

 

[yoop89]

Most likely you don't see the bubbles going back because it happens slowly behind the chiller's closed door.
I connect a urine bladder between the fermenter and the airlock to harvest CO2 for cold crash, and it decreases by 1-1.5 liters approximately while cold crashing, so I guess that's roughly the volume being sucked in.

Well I've followed all the fermentation, and I could clearly hear the bubbles of the Co2. As you say that the space is rapidly filled, so while I chill the fermenter I should hear or see this clear bubbling. This make me think that the only reason I don't hear or see any bubble is because the amount of O2 gone through the airlock is very little, and so I can not hear it. The amount of Co2 that get out during fermentation is not very huge, but you hear that sound for days.

mediant says his fermenter draws back up to 1.5 litres? That seems like quite a bit when on average headspace is normally 4-5 litres. Also, cold crashing is a slow event, like others have said the "bubbles" of sucking back air happen slowly while the beer is cooling from your ferm temp to whatever you are crashing to.

 

[marchio-93]

mediant says his fermenter draws back up to 1.5 litres? That seems like quite a bit when on average headspace is normally 4-5 litres.

I've got 10 litres of headspace, that were full of Co2, before this stupid cold crashing