Cold crash and oxidation

[marchio-93]

Hello everyone! Very often, during the cold crash (20° - - - > 2° C) , the pressure drops (I think it's normal, the temperature drops and therefore also the pressure). I'm afraid the beer can oxidize, so there is enough CO2 to protect my liquid son?

 

[Loud Brewing]

Nope. You need to hook up c02 source during crash. Try using a carb cap with a small section of tubing attached and then connect a tank and set regulator to 2-3 psi. Not sure if your bucket is air tight but give it a shot.

 

[marchio-93]

It is not air tight

 

[RPh_Guy]

To really minimize oxidation, it's better to not cold crash at all. Spunding is the best option, or at least packaging right after fermentation completes.

Cheers

 

[marchio-93]

To really minimize oxidation, it's better to not cold crash at all. Spunding is the best option, or at least packaging right after fermentation completes.

Cheers

Thanks! My question is, do a few days of cold crash oxidize beer in a strong and recognizable way?

 

[mkopec1]

Inside of the bucket you should be ok because Co2 is heavier than air. So that beer, while not being stirred around and splashed about should be covered by a layer of Co2 from the ferment process. In fact most of the area inside the bucket between the lid and the beer should be Co2.

The minute pressure difference when cold crashing in bucket will not be enough to expose the beer to O2, because again any that gets int he bucket will rise above the Co2 which is heavier.

 

[RPh_Guy]

Thanks! My question is, do a few days of cold crash oxidize beer in a strong and recognizable way?

To my taste, yes, strongly.

 

[RPh_Guy]

Co2 is heavier than air. So that beer, while not being stirred around and splashed about should be covered by a layer of Co2 from the ferment process. In fact most of the area inside the bucket between the lid and the beer should be Co2.

This is incorrect. Gases mix, very rapidly.

 

[Loud Brewing]

Deleted. Duplicate post

 

[Loud Brewing]

Inside of the bucket you should be ok because Co2 is heavier than air. So that beer, while not being stirred around and splashed about should be covered by a layer of Co2 from the ferment process. In fact most of the area inside the bucket between the lid and the beer should be Co2.

The minute pressure difference when cold crashing in bucket will not be enough to expose the beer to O2, because again any that gets int he bucket will rise above the Co2 which is heavier.

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

 

[Loud Brewing]

Thanks! My question is, do a few days of cold crash oxidize beer in a strong and recognizable way?

It will develop a wet cardboard taste very quickly. This is one reason to invest in a proper carboy that is air tight

 

[marchio-93]

It will develop a wet cardboard taste very quickly. This is one reason to invest in a proper carboy that is air tight

Excuse me, I'm not good in English. My carboy doesn't let air in anywhere, so it is air tight in this sense. I just don't know if it can be pressurized with the C02, I think not being a simple bucket.

 

[McKnuckle]

If it was sealed enough to allow your airlock to bubble, and you can avoid drawing the airlock liquid into the bucket (which would then create a passage for air to enter the bucket), then I think you'll avoid oxidation.

Otherwise I agree with the other fellows here on the basic principles stated.

 

[Loud Brewing]

If it was sealed enough to allow your airlock to bubble, and you can avoid drawing the airlock liquid into the bucket (which would then create a passage for air to enter the bucket), then I think you'll avoid oxidation.

Otherwise I agree with the other fellows here on the basic principles stated.

You will suck all the airlock liquid into the beer every time, the suck back from the temperature change is quite substantial.

 

[Loud Brewing]

Excuse me, I'm not good in English. My carboy doesn't let air in anywhere, so it is air tight in this sense. I just don't know if it can be pressurized with the C02, I think not being a simple bucket.

You don't really need to "pressurize" it. Hook up a carb cap like I mentioned and set your regulator very low and all it will do is draw in c02 instead of oxygen.

 

[marchio-93]

You will suck all the airlock liquid into the beer every time, the suck back from the temperature change is quite substantial.

The liquid in the airlock is the same from the beginning of the fermentation, so i've not sucked it into the beer, I think.
However I don't know if it's sure that 02 get into the bucket when pressure drop. I think the airlock would bubble, as when the Co2 get out

 

[Loud Brewing]

The liquid in the airlock is the same from the beginning of the fermentation, so i've not sucked it into the beer, I think.
However I don't know if it's sure that 02 get into the bucket when pressure drop. I think the airlock would bubble, as when the Co2 get out

as mentioned above, if you bucket is airtight enough for your airlock to work and you cold crash it, it will work in reverse and suck liquid and then oxy. have you cold crashed it already?

 

[marchio-93]

as mentioned above, if you bucket is airtight enough for your airlock to work and you cold crash it, it will work in reverse and suck liquid and then oxy. have you cold crashed it already?

So can we say that as long as I do not suck water, oxygen will not enter?
Yes I've cold crashed it

 

[RPh_Guy]

The liquid in the airlock is the same from the beginning of the fermentation, so i've not sucked it into the beer, I think.

The s-shaped airlock allows air to be sucked in just as it allows CO2 to escape. Air definitely got sucked in.

 

[marchio-93]

The s-shaped airlock allows air to be sucked in just as it allows CO2 to escape. Air definitely got sucked in.

But when the Co2 get out there is a continuous bubbling, why would not be the same for 02?

 

[RPh_Guy]

Yeast produce a huge amount of carbon dioxide, enough to fill dozens of buckets with pure CO2 gas.

The amount of air sucked in is much less, but it only takes a tiny amount to adversely affect the beer.

 

[Loud Brewing]

Enjoy the beer, drink it fast and move to make improvements in your process next time.
Dissolved oxygen is enemy #1 to beer, do everything you can to reduce it.

 

[balrog]

People capture CO2 from fermentation in balloons and such so that with cold crash the head space gas contraction gets replaced by the captured CO2. You could look into that if you want, but it is a process. If you keg, there are lots of things you can do, from purging the keg you eventually closed transfer into, or just ferment and serve from the keg. It can get complicated fast, but it is a fun hobby.

 

[Jag75]

The s-shaped airlock allows air to be sucked in just as it allows CO2 to escape. Air definitely got sucked in.

This is what I learned also . I thought the air didnt get sucked in because the water was still in it . Then @Dgallo stated something to the effect of the water stays in when co2 is pushed out . I had a light bulb moment once I read that lol. It makes total sense . It was my son n laws mead . I dont cold crash and have never before . Except his mead .

 

[mkopec1]

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

I could be wrong, a couple of caveats, I never crashed inside a bucket, I only crash in glass. And from what I gather, while yes, gasses mix, you cannot deny that Co2 is heavier than air and it will always blanket the beer if you dont disturb the process too much. You can see this with a block of dry ice and the fog they create with it, it always sticks around by the ground. Besides this is a few days if that were talking about ,not weeks or months. Its not like hes shaking the thing up, or at least I hope hes not.

While air might get sucked into the container, it will still be lighter than the Co2 thats blanketing the beer. If this was a problem like you say, then every beer that was produced by home brewers that do not have closed transfer systems would be oxidized by O2 and this is just not true. Especially back int he day when they were preaching about primary and secondary ferments back in the 80s and 90s.

Like I said I could be wrong but I never experienced oxidation by cold crashing inside my carboy ever. Only time I ever got oxidation in any form was in the early days of not knowing about this and transferring the beer and bottling haphazardly.

 

[RPh_Guy]

you cannot deny that Co2 is heavier than air and it will always blanket the beer if you dont disturb the process too much.

Nope, completely incorrect. The gases completely mix within seconds. The particles are moving at hundreds of miles per hour. There is no "blanket".
If there were, your lungs will be full of CO2 and you would suffocate.

The visible "gas" coming off dry ice is actually water vapor from the extreme cold.

Not everyone tastes oxidation, or realizes that's what they're tasting. It occurs in degrees. First it affects hop flavor and then the beer goes through a series of changes.

 

[bob1852]

If this was a problem like you say, then every beer that was produced by home brewers that do not have closed transfer systems would be oxidized by O2 and this is just not true.

Actually, most homebrews (and many commercial) beers are oxidized....but most tasters don't perceive minor oxidation.....likely because we've all read that oxidation tastes like cardboard or sherry.

Unfortunately, cardboard/sherry flavors are from extreme oxidation.

Minor oxidation is different. It can be described as muted, dull flavors, and some other key characteristics that some others may care to add. And it gets worse over time...

Since I've paid more attention to oxidation, I'm actually shocked how many commercial beers suffer from it.

The best way I can describe it is: if there's something slightly "off" with a beer, and you can't clearly point to anything else, it's oxidation.

 

[marchio-93]

The best way I can describe it is: if there's something slightly "off" with a beer, and you can't clearly point to anything else, it's oxidation.

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

 

[STMF]

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

 

[marchio-93]

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

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

 

[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