The whole "cold crashing, oxidised beer" debate??

[DonGavlar]

So with all my beers thus far I've just used finings in the boil and then given lengthy ferm times and cold conditioning times.
I've been quite happy with my beers but still never had a really super clear beer that I'm happy with.
So, now that I've got a ferm chamber set up, I wanted to start cold crashing my beers followed by a dose of gelatin. I figured with boil finings, quick cooling times, 3 weeks in the fermenter, a week cold conditioning and now a cold crash followed by gelatin too, that surely I'd have a good chance of some really nice clear beers.

I was reading up on proper cold crashing techniques to only discover a large amount of people suggesting that..
1) Im going to oxidise my beer from the air being sucked by vacuum
2) My glass fermenter will EXPLODE

I've realised it's obviously better to just keg and cold crash under pressure but I don't have a kegging system and wont have one for some time.

How much truth is in the whole oxidisation theory? I feel that so many people cold crash in the fermenter, surely people would have stopped by now if oxidisation was an issue? And will my glass fermenter really break under the pressure from just a 30F drop or so?

Any advice would be appreciated, I feel that now I have the oxidisation thing in my head im going to think I'm picking up on oxidized off flavours when they aren't really there.

 

[day_trippr]

- Barring provisions to avoid it, there will be some oxygen up-take when cold-crashing any fermentor. Physics and chemistry will have their way.
- I've been cold-crashing my 6.5g italian carboys for over a decade now, for the last couple of years with a half-psi of CO2 on top. No issues.

I do let them come back up to room temperature on their own before cleaning to avoid thermal shock...

Cheers!

 

[DonGavlar]

- Barring provisions to avoid it, there will be some oxygen up-take when cold-crashing any fermentor. Physics and chemistry will have their way.
- I've been cold-crashing my 6.5g italian carboys for over a decade now, for the last couple of years with a half-psi of CO2 on top. No issues.

I do let them come back up to room temperature on their own before cleaning to avoid thermal shock...

Cheers!

So have you ever had any oxidisation problems when cold crashing, is the amount of oxygen introduced even significant seeing as from the point of cold crash, all the beer will be enjoyed within say 5 weeks. Is that even enought time for a oxidisation to take place?
I think I actually saw an old post from you where you actually have some kind of set up to alow zero oxygen contact while cold crashing and transfering to keg.

On point number two, i now see they mean using a glass carboy with a solid bung could be dangerous seeing as there would be a sealed vacuum and ofcourse glass under positive or negative pressure could be an issue.

Relly want to crash with this gelatin trick as I do love a crystal clear brew.. but now im just worried about oxidisation. Man i can’t wait till I can afford a proper keg setup

 

[Smellyglove]

So have you ever had any oxidisation problems when cold crashing, is the amount of oxygen introduced even significant seeing as from the point of cold crash, all the beer will be enjoyed within say 5 weeks. Is that even enought time for a oxidisation to take place?
I think I actually saw an old post from you where you actually have some kind of set up to alow zero oxygen contact while cold crashing and transfering to keg.

On point number two, i now see they mean using a glass carboy with a solid bung could be dangerous seeing as there would be a sealed vacuum and ofcourse glass under positive or negative pressure could be an issue.

Relly want to crash with this gelatin trick as I do love a crystal clear brew.. but now im just worried about oxidisation. Man i can’t wait till I can afford a proper keg setup

Oxidization doesn't take long to take it's hold on any good beer. But, most people who are not that familiar with oxidization-effects think of it as that card-board-stale-thing you read about.

That happens when the oxygen ingress has been severe, when it's gone this far, the beer will end up like rubbish.

The first effects of oxidization is loss of flavor or aroma. A beer can suffer from oxidization, without tasting like cardboard, or paper-y. So any oxygen ingress will strip the taste and aroma of a beer, without it "going bad". It might just taste less. Which is sub-par comparing to how good it could taste.

I hear and read lots of comments about "that's not enough (o2), it'll be fine" or "Never had any problem with oxidization doing this or that". My only guess is that people writing these comments does not have the experience with oxidization on lower levels, maybe they are just used to their own beer tasting less than it could.

 

[DonGavlar]

Oxidization doesn't take long to take it's hold on any good beer. But, most people who are not that familiar with oxidization-effects think of it as that card-board-stale-thing you read about.

That happens when the oxygen ingress has been severe, when it's gone this far, the beer will end up like rubbish.

The first effects of oxidization is loss of flavor or aroma. A beer can suffer from oxidization, without tasting like cardboard, or paper-y. So any oxygen ingress will strip the taste and aroma of a beer, without it "going bad". It might just taste less. Which is sub-par comparing to how good it could taste.

I hear and read lots of comments about "that's not enough (o2), it'll be fine" or "Never had any problem with oxidization doing this or that". My only guess is that people writing these comments does not have the experience with oxidization on lower levels, maybe they are just used to their own beer tasting less than it could.

That is good to know, especially as I see some people saying oxidisation takes months and months to really present itself.
Im guessing you are against the idea of me cold crashing then, seeing as I will be sucking o2 into the beer?

 

[Smellyglove]

That is good to know, especially as I see some people saying oxidisation takes months and months to really present itself.
Im guessing you are against the idea of me cold crashing then, seeing as I will be sucking o2 into the beer?

Not unless you can prevent it sucking in, and let the fermentor sit for an extended time. I always CC my hoppy ones. Some oxidization will probably occur, but the beers are mostly gone in 2-3 days. I use buckets for y hoppy ones, and just before I CC i swap the airlock out with a rigid gass-hose which fits in the hole, where the airlock sat, which is melted together in one end. I usually raise temps just a little bit before CC, just to get some more "buffer-co2" out of solution, then CC. The lid bulges inwards after CC, so I guess there's not much suckback of o2, if the lid wouldn't be as tight the lid wouldn't bulge inwards.

 

[DonGavlar]

Not unless you can prevent it sucking in, and let the fermentor sit for an extended time. I always CC my hoppy ones. Some oxidization will probably occur, but the beers are mostly gone in 2-3 days. I use buckets for y hoppy ones, and just before I CC i swap the airlock out with a rigid gass-hose which fits in the hole, where the airlock sat, which is melted together in one end. I usually raise temps just a little bit before CC, just to get some more "buffer-co2" out of solution, then CC. The lid bulges inwards after CC, so I guess there's not much suckback of o2, if the lid wouldn't be as tight the lid wouldn't bulge inwards.

Damn.. guess ill just have to wait till I have a keghing system

 

[eric19312]

http://www.norcalbrewingsolutions.com/store/CO2-Carbon-Dioxide-Harvester-Kit.html

This might do the trick for you

 

[MaxStout]

I second that CO2 Harvester. Not cheap--runs $50 and you need to supply the jars. But nice knowing that your fermenter is sucking back CO2 and not air. Also prevents suckback of liquid through the blowoff tube.

 

[Bassman2003]

I wonder how much volume the Nor-Cal setup handles? Seems like you have a limited amount of CO2 to put back in if your headspace is kind of large.

To the OP, I would not put your glass carboy under pressure with a solid bung while chilling. Mother nature always finds a way to win in the situations! I have been looking into this lately and am considering CO2 or the Nor-Cal solution. Oxygen is good to avoid. I am also considering keg priming to scavenge the O2 after the beer leaves the fermenter.

 

[jeeppilot]

Since you aren’t kegging, you must be bottle conditioning. When you cold crash, transfer quickly afterwards to bottle. When the yeast consume your priming sugar, they’ll scavenge much of whatever o2 you take on. You’ll need to account for your beer being cold when you calculate your priming sugar.

 

[DonGavlar]

Since you aren’t kegging, you must be bottle conditioning. When you cold crash, transfer quickly afterwards to bottle. When the yeast consume your priming sugar, they’ll scavenge much of whatever o2 you take on. You’ll need to account for your beer being cold when you calculate your priming sugar.

It’s always been my understanding that unless you are cold crashing for a significant length of time, for instance say 2 weeks, you are better off using the temperature that the beer was fermented at. Apparently this is the case as in a short cold crash 1-3 days, not enough co2 reaches equilibrium and actually is fully absorbed into the beer to make a huge difference. I’ve read alot of posts where people state they have had better results using their fermentation temps as a mean of calculating priming sugar.

Ofcourse this may have been old info that has now been proven wrong? Can anyone expand on this?

This is all seeming a bit too much for its worth.. I may just not bother with a cold crash until I can keg. All these conflicting problems seem to just be putting too much worry into a hobby that should be relaxed and enjoyable!

Thanks all for the info

 

[thehaze]

When calculating the amount of sugar needed to prime a batch of beer, the calculations should take into account the temperature of the beer during fermentation ( the highest one at that ). Let's say you fermented at 63 and raised the temp. at the end to 66 to encourage the yeast to finish and clean after itself. You will be fine using 63 when calculating the priming sugar.

I have used this for the last 19 batches and have yet to experience issues. Other will also point to the same methodology.

I also cold crash and still prime the way described above. The beer does get a tad warmer during the transfer, bottling, etc. as I always take it out from the fridge at least one hour before starting the bottling process, so if any yeast or hop debris rose up while I took it out, would have time to maybe settle at the bottom again. But it has never been an issue.

 

[DonGavlar]

When calculating the amount of sugar needed to prime a batch of beer, the calculations should take into account the temperature of the beer during fermentation ( the highest one at that ). Let's say you fermented at 63 and raised the temp. at the end to 66 to encourage the yeast to finish and clean after itself. You will be fine using 63 when calculating the priming sugar.

I have used this for the last 19 batches and have yet to experience issues. Other will also point to the same methodology.

I also cold crash and still prime the way described above. The beer does get a tad warmer during the transfer, bottling, etc. as I always take it out from the fridge at least one hour before starting the bottling process, so if any yeast or hop debris rose up while I took it out, would have time to maybe settle at the bottom again. But it has never been an issue.

Yes, this is exactly the way I’ve considered appropriate. To me, the 1-2 days that I would cold crash would not be long enough for the headspace co2 to fully enter the beer. Not enough co2 to account for the amount of sugar differnce given by beersmith when changing the temp down to 34F. That was my thoughts anyway, I may be completely wrong.

Just to add, so that i have another opinion from someone who crashes before bottle conditioning rather than kegging.. have you experienced any oxidation issues? Do you just leave a regular airlock on the fermenter when crashing or are you sealing it or some other method to stop oxygen being sucked in?

 

[eric19312]

Yes, this is exactly the way I’ve considered appropriate. To me, the 1-2 days that I would cold crash would not be long enough for the headspace co2 to fully enter the beer. Not enough co2 to account for the amount of sugar differnce given by beersmith when changing the temp down to 34F. That was my thoughts anyway, I may be completely wrong.

Just to add, so that i have another opinion from someone who crashes before bottle conditioning rather than kegging.. have you experienced any oxidation issues? Do you just leave a regular airlock on the fermenter when crashing or are you sealing it or some other method to stop oxygen being sucked in?

My understanding is that in the example above you should use 66 in the calculator. I’m sure difference between 66 and 63 is insignificant but the greater the difference between starting temp and final temp the more important.

As the beer warms solubility of CO2 drops and the CO2 in solution will bubble out. This process is pretty fast ... just guessing but I’d guess minutes or hours not days.

So most frequent advice I see for temp to use in the calculator is highest temperature the beer was at after fermentation was complete. This is the active fermentation phase where CO2 is still being generated by yeast....not the resting or cleanup phases.

 

[DonGavlar]

My understanding is that in the example above you should use 66 in the calculator. I’m sure difference between 66 and 63 is insignificant but the greater the difference between starting temp and final temp the more important.

As the beer warms solubility of CO2 drops and the CO2 in solution will bubble out. This process is pretty fast ... just guessing but I’d guess minutes or hours not days.

So most frequent advice I see for temp to use in the calculator is highest temperature the beer was at after fermentation was complete. This is the active fermentation phase where CO2 is still being generated by yeast....not the resting or cleanup phases.

Yes this is what I would do, however, people have also said to me that if I cold crash the beer to say 34F wnd then bottle at 34F then I need to put 34F into beersmith to calculate sugar amount. However, I can’t see why I would do that as in the short cold crash, the beer wouldnt absorb the same amount of co2 from the headspace as the differnce in putting that cold temp into beersmith. So yes, I would personally go with the method you just stated. Unless someone has some sort of findings that this method is wrong?

 

[DonGavlar]

But anyways...
I’m pretty confident that wether you cold crash or not, fermentation tempature should be input into the priming calculator, not the temp of the beer at bottling.
So all im really anxious about now is still just the oxidisation thing.. I guess I just give it a go and if my beer turns out oxidised, ill have a good idea what caused it.

 

[Bassman2003]

If you are cold crashing then bottling you need to take into account the temperature you are bottling at is not very conducive to yeast activity. Basically meaning 34f is too cold for your yeast to ferment and create CO2. The Belgians put their beers in 70-85f "warm rooms" for the bottle conditioning stage then cool them down. This ensures the yeast will be active for the secondary fermentation. But this is after cold crashing the beer then adding an additional charge of yeast for bottling.

 

[DonGavlar]

If you are cold crashing then bottling you need to take into account the temperature you are bottling at is not very conducive to yeast activity. Basically meaning 34f is too cold for your yeast to ferment and create CO2. The Belgians put their beers in 85f "warm rooms" for the bottle conditioning stage then cool them down. This ensures the yeast will be active for the secondary fermentation. But this is after cold crashing the beer then adding an additional charge of yeast for bottling.

It was my understanding that you are to input the fermentation temp so that the software can gauge how much co2 was created to start with? Even though I will be bottling at cold crash temps, the bottles will be stored in boxes in a room at 72F for 3 weeks. Therefore surely once the bottles temps raise up to that 72 mark they will be producing the exact same amount of co2 as they would have if i didnt cold crash?

 

[Bassman2003]

Well, if you cool the active yeast down to 34f your are basically putting them into a coma after working for the fermentation. they are tired at this point and you just put them into a deep freeze. I would not expect them to behave as you want after you warm up the bottles. But, I could be wrong if others have used this method and had consistent results. I stopped bottling because I had inconsistent results even keep the beer at the same fermentation temps through bottling.

 

[thehaze]

I usually cold crash for 2 days, take the fermenter out of the fridge and then I begin rinsing the bottles and all equipment. I boil water and dump the priming sugar, I mix for 30-60 seconds and the solution is ready. I then cool down the sugar solution. I sanitize my bucket and then dump the sugar solution and then transfer from the fermenter. While the beer is transfering, I santitize the bottle with my Avinatore and hang them in the bottle tree. I bottle and then I set the bottles in a spot around the house, where the temp. should be around 68-72 F.

I can feel the cold of the beer when I fill the bottles, but that has never been an issue. I bottled 19 batches last year and did not encounter any issues with either lack of carbonation or gushers. The temp. for calculating priming sugar was the temp. I fermented the beer at. This was for different beers starting from 4.3% ABV and up to 9.2% ABV.

 

[Bassman2003]

Makes sense if you are raising the temps of the bottles in secondary fermentation. The yeast just needs to be warm to be active.

 

[MHBT]

I second that CO2 Harvester. Not cheap--runs $50 and you need to supply the jars. But nice knowing that your fermenter is sucking back CO2 and not air. Also prevents suckback of liquid through the blowoff tube.

i tried this rig, made i DIY version and air still gets in the fermenter during CC.

 

[brewbama]

I second that CO2 Harvester. Not cheap--runs $50 and you need to supply the jars. But nice knowing that your fermenter is sucking back CO2 and not air. Also prevents suckback of liquid through the blowoff tube.

I made the same thing for a lot cheaper. Works great.

 

[MHBT]

I made the same thing for a lot cheaper. Works great.

All that trapped co2 gets pulled back in the the headspace but air also gets pulled in, the co2 does not create a "blanket" like some people think, the gasses will ultimately mix given enough time