Oxygen suckback during cold-crashing

[BeerCat]

I started putting a small balloon over the airlock near the end of fermentation. The fv lid is normally bulging and when it crashes it sucks it back in. The balloon never full inflates but it normally stops any suck back (that i can see). I ran out of balloons so reused one and when i opened the fridge it was sucking in air like mad. I have had to ditch a few batches of lager recently that were oxidised so need to fix this problem.
Has anyone tried the plaato valve? I know @David Heath has done a review of it but i am unsure if it only stops liquid getting in and not air?
Does the double jar blow off tube setup work well? It would be a pita for me as i sometimes move my fv's around.
Has anyone tried the bladder setups? At some point i will have to get a conical and another fridge but for now really need to find a solution.

 

[Braindead]

Try my method, attach a bladder from a camelback a few days before fermentation is finished.
It will naturally inflate with co2, you may need top release a little at times.
Then it only sucks back co2 when crashing.
Works a dream

https://www.ebay.co.uk/itm/2L-Hydra...228162&hash=item3b30def0df:g:VEMAAOSwGN5dDe61

 

[BeerCat]

Try my method, attach a bladder from a camelback a few days before fermentation is finished.
It will naturally inflate with co2, you may need top release a little at times.
Then it only sucks back co2 when crashing.
Works a dream

https://www.ebay.co.uk/itm/2L-Hydra...228162&hash=item3b30def0df:g:VEMAAOSwGN5dDe61

And you attach this to a regular airlock like this?

 

[simon12]

I never found oxidation a problem but a simple solution could be:
Before you cold crash fill the entire gas space above the beer by putting 2L sterilised water bottles in until its filled to the brim then seal the lid airtight, there is then no CO2 to dissolve into the beer and no air can get in or out. I have no idea if this works but the only problem I can see is if the beer still contracts enough to collapse the fermenter. Or based on the same principle you could brew stronger and just add water to the brim.
I am working on something to extend the life of cask beer that involves harvesting the CO2 from it and keeping it in a bladder that could be adapted for this but am still waiting for the last few fittings to be delivered.

 

[Druncan]

@simon12 Thinking along the same lines. But, I was thinking of re-using 5l winebox liners. We go through loads. Just can't get the taps out tried a screwdriver and nearly eviscerated myself,,, must be some was to remove them without serious risk of self harm

 

[simon12]

@simon12 Thinking along the same lines. But, I was thinking of re-using 5l winebox liners. We go through loads. Just can't get the taps out tried a screwdriver and nearly eviscerated myself,,, must be some was to remove them without serious risk of self harm

I was planning to use the 10L ones as I have a load of empty ones, for casks I really want 40L ones but it looks like 20 is the biggest. You can buy this https://www.vigoltd.com/Catalogue/Fittings/Vitop-connector-for-bag-in-box-79732 to connect beer line to the tap without removing it or cheaper from China https://www.ebay.co.uk/itm/223316758227 .

 

[pottsworth]

I’m sure heard on one of the podcasts people talking about using catheter bags to catch the CO2

 

[BeerCat]

I’m sure heard on one of the podcasts people talking about using catheter bags to catch the CO2

I watched a video where the guy used something like this but you need one without a non return valve. The output went into a bottle of starsan. I still would not be able to move it though. @Braindead balloon sounds like a much better idea.

 

[Ghillie]

Never had an issue with oxygen. What’s more is that I think this problem is fictional in a lot of cases.

So here’s my take. Americans always complain about O2 exposure during cold crashing. Why? Because a lot of them use glass carboys. There’s zero give in the glass, the smallest pressure differential will force gas out/pull gas in.

Ferment in a plastic bucket, like a lot of us do, with an S type air lock then O2 “suck-back” is just not a thing. The FV becomes pressurised with the lid swelling a good bit before gas escapes through the air lock. The same is true in reverse, all that expanded gas would have to shrink so much before any vacuum would pull O2 back into the FV.

FYI - I’ve proved this sound multiple times when cold crashing at -1C in my plastic bucket FV’s. Unless you’re using glass, stainless or any vessel with zero flexibility - it’s a complete non-issue.

 

[Braindead]

Attach it to the blow off pipe from carboy.
I've tried many methods as make a, lot of Neipas and try to eliminate all oxygen, I alsok had a litre of suckback previously when crashing.
This method works a treat.
Just keep an eye on the bladder incase it explodes that's why u may need to release every now and again before crasjing

I usually attach after 5 days

 

[BeerCat]

Ordered one. I am going to put a syphon tap on the blow off tube so i can close it if i have to move it.

 

[Honk]

Intrigued by this, I've just replaced the airlock with a 10 litre vinotainer to see how long it takes to inflate. Beer is a 1.044 og Patersbier 24 hours into fermentation.
More an experiment really as never noticed a problem, but then I've never brewed a NEIPA.
It is something I've been thinking about though as a potential problem, tempted to do away with the cold crash altogether and maybe transfer to a second keg if necessary.

Edit: looks like my fermenter needs a clean, residue from oxiclean on the top.

 

[The Baron]

Simples its already been answered in these posts fill a balloon with co2 either from harvesting it or from your gas cylinder and put it over the bung so that it can take co2 into the fermentation chamber during crashing hence no oxidation, me myself never had a problem so don't bother

 

[Honk]

Around 2 hours to collect 10 litres of co2 during active fermentation, or use a gas cylinder as suggested by @the baron above. Reckon my vinotainer is easier to use than a balloon though, it has a tap which is turn on and offable.

 

[simon12]

@simon12 Thinking along the same lines. But, I was thinking of re-using 5l winebox liners. We go through loads. Just can't get the taps out tried a screwdriver and nearly eviscerated myself,,, must be some was to remove them without serious risk of self harm

This is what I just made for casks
https://www.thehomebrewforum.co.uk/threads/cask-beer-life-extender.82841/
it could easily be adapted for a fermenter but honk and braindead versions are much simpler.

 

[Ben034]

View attachment 19967
Around 2 hours to collect 10 litres of co2 during active fermentation, or use a gas cylinder as suggested by @the baron above. Reckon my vinotainer is easier to use than a balloon though, it has a tap which is turn on and offable.

Does it hold the gas for a few days if you turn the tap to off and take out of the bung?

 

[Honk]

Does it hold the gas for a few days if you turn the tap to off and take out of the bung?

It does, I removed it once full but now fermentation has finished it's back in place, it will be interesting to see how much it shrinks once I begin to cold crash.

 

[Ben034]

It does, I removed it once full but now fermentation has finished it's back in place, it will be interesting to see how much it shrinks once I begin to cold crash.

Would be interested. Please let us know.

 

[Braindead]

My bike bladder pretty much fully shrinks. So it goes to show how much o2 could be sucked into the Ferm if people choose not to try these methods

 

[Sadfield]

I'm pretty sure there's enough credible science out there that shows beer can oxidise quickly. Again, things in brewing aren't binary, oxidation won't instantly ruin a beer. However, not all beers are equal, nor is the rate of degredation. Some oxidation can be a good thing, we are lead to believe by CAMRA. Yet we know that the glorious oxidised qualities of a cask that is allowed to breathe are fleeting and beer lasts three days before the positive effects soon give way to the negative effects. Oxidation is not in the imagination. It's a very real and evident aspect of brewing, whether you want to avoid a hopless IPA or enjoy beautifully aged Imperial Stout.

Taking steps to reduce oxidation where it's not desired is a good thing. So I'm not sure why anyone would have a problem with a brewer willingly putting in a modicum of effort in order to brew the best beer they can. If I was brewing NEIPAs I'd be taking oxygen suck back very seriously. I'm not, so don't.