Cold crashing suck back solutions

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Jtk78

Jtk78

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I was researching how to prevent suck back during cold crashing. I was really looking to find out how to hook up a co2 ballon. Does it go on the airlock? If anyone has any input on that, I'm still all ears because I still haven't found that.

Anyway, in my research I stumbled a post on another forum with someone that inverts the ballon per the pictures below. Seems pretty ingenious, but I'd be concerned with off flavors from the ballon. Although I use a 7 gal Fermonster so the ballon may not get to the beer anyway. Obviously the balloon would need to be cleaned and sanitized. Thoughts?

Before cold crashing
20170108_064516_zpsyzgh39xr.jpg



After cold crashing
20170108_064456_zpszaewc1rq.jpg
 
It looks cool, but do you want the risk of the ballon deciding to pop off the carboy lip and drop into the beer, exposing the opening and defeating the whole purpose? Seems like overkill. I just fit sanitized foil for a day or so with a thick rubber band, then replace it with a solid bung once I'm sure the beer is cold and stable.
 
RM-MN said:
Get an "s" shaped one piece airlock. If you don't overfill it the liquid won't suck back.
Click to expand...

It may not suck the liquid back, but it will suck air right through the two bubbles, correct? What I'm trying to prevent is the introduction of air to the carboy. I also don't buy CO2 in the carboy acts as a protective blanket from the new air.
 
When CO2 production from an active fermentation ends the head space in the fermentor will equalize with the atmosphere with or without an air lock. The molecules that make up our air will always seek equilibrium. We can't stop it unless the fermentor would be hermetically sealed. Air passing through the air lock during cold crashing is just a little faster but the results are the same. We can only slow the rapidity of oxidation by reducing the surface area of our beer exposed to air or introducing CO2 to keep the concentration of molecules greater than what is in our air.


Balloons are also porous. That is why they will not stay inflated forever but they would slow the process of equilibrium.
 
Agree with the above comment about the foil. It's super easy, cheap, and sanitary. I still make sure to dip the foil in star san to be on the safe side!
 
What i do is use a big empty water jug, put a lit on with 2 holes, and use the principal of a bong - for fermention, the blow off tube from the fermentor goes in 1 hole, all the way down into some sanitizer in the bottom, and there is an airlock in the other hole. then when cold crash raise the blow off tube out of the sanitizer, and switch out the air lock for a piece of tubing that goes down into the sanitizer. the jug fills up with CO2 during fermentation, then that gets sucked back out (like smoking a bong, no water gets sucked up only air) during cold crash
 
I ferment in better bottles and plug the hole in the bung with a rubber plug. After cold crash, I can put a rubber glove inflated with CO2 over the bung and release the plug through the glove, causing the better bottle to suck in the CO2.
 
are you having problems with oxidation in your beer? or is this just an OCD theoretical concern?

i've never had a problem, so I just cold-crash overnight to 40-50 degrees (whatever the garage is at in the winter), and don't worry about it. That's enough to get all the dry hops to drop to the bottom.

sure, maybe some air gets in there.... big deal. it's going to get exposed to air when I bottle too.
 
Here's what I've been doing for a year or so now.

After primary ferment is over and I'm getting ready to cold crash, I'll attach a bag filled with CO2 to the fermenter. Anything it's pulling into the fermenter is CO2.

This is on my conical. You can use the same thing in a carboy, just put the tube into a bung. The bag I use on my conical is a 2 gallon ziplock. To attach the tubing, I'll cut a small part of the corner off, just enough to make a hole that's a bit smaller than the tubing, then push the tubing through from the inside. Seal with a wrap or two of high quality electrical tape on the outside.

It's cheap and easy, and it minimizes O2 pickup.

suckback.jpg
 
The_Bishop said:
Can't do full 5 gallon batches that way.
Click to expand...

Why are home brewers so tied to the 5G batch size? It's kind of an arbitrary number if you think about it. Other than commonly available carboy and bucket sizes it really doesn't matter all that much. For kegging purposes it makes sense to be in increments close to 5G though.

If you do it right you can easily get better than 4.5 G into the serving keg. I actually get closer to 4.7G into a serving keg. There are a few trick though. Also at this volume i can actually do 3x5G also, which more than makes up for the slightly lower per keg volume.

The move to corny fermenting has a lot more benefits than it seems.
 
I use a Speidel 60L and added a corny post to the solid lid. You could also use an extra valve cap. I swell the fermenter with 2-3 psi at the start of cold crash. Repeat a few times over the next 36 hours. I tap the lid with a rubber mallet to ensure the seal is good. The Speidel holds a few psi just fine.
For other vessels(glass), you could use a balloon over the airlock near the end of primary fermentation. Let it capture the co2 of the end of fermentation, then supply the gas for cold crash. I would use one of those big thick punch balloons that kids bounce on.
For buckets, I don't see a way to do it. They just don't seal well enough.
I have ceased doing extended cold crashing now and rack into purged and primed kegs through a closed loop. I cut about 3/4 inch off all my diptubes and have been happy with that. If I need to dryhop, I use bagged hops in the keg. I'll add them after the purge(co2 pushed starsan) by opening the lid with co2 running at about 3 psi. Drop it in slowly. That minimizes o2 and the secondary/priming takes care of the rest of the o2. Ill add a few psi to the purged keg, attach a disconnect to the liquid post to relieve pressure, flushing the hose of air and attach that to the out spigot of the fermenter. Another loop is sent from the gas post to the top of the fermenter, feeding the co2 that is displaced by the beer back into the fermenter, instead of air.
If I'm not dryhop, I use the same process but dose the keg with priming sugar with a large syringe into the liquid hose before attaching to the fermenter.
Note, I limit the amount of hops/trub going into the fermenter to begin with by whirlpooling and using bags for my late addition hops. Only bittering additions to straight into the kettle.
If you try to employ this, the weak link is hops clogging the poppet/post/disconnect. You can circumvent this by removing the spring and pin from the disconnect and the poppet from the keg post.
Just some other ideas for you to consider
Cheers
 
Jaybird made the mason jar toppers to help me deal with suck back. I'm not saying it's going to keep 100% of the air out but with the batches I have used it on so far, there has been zero suck back. I thought the fluid may suck back into the second mason jar when cold crashing, but I haven't had that happen yet.

IMG_20161211_121532512.jpg
 
schematix said:
Why are home brewers so tied to the 5G batch size? It's kind of an arbitrary number if you think about it. Other than commonly available carboy and bucket sizes it really doesn't matter all that much. For kegging purposes it makes sense to be in increments close to 5G though.

If you do it right you can easily get better than 4.5 G into the serving keg. I actually get closer to 4.7G into a serving keg. There are a few trick though. Also at this volume i can actually do 3x5G also, which more than makes up for the slightly lower per keg volume.

The move to corny fermenting has a lot more benefits than it seems.
Click to expand...

Well, I keg. With all the other effort being the same, I'd rather end up with a full keg. Also, my fermenters are far easier to clean than a corny keg.

Aside from fermenting under pressure, which is a dubious-at-best benefit, what else is to be gained from fermenting in a corny? Smaller batch size and more difficulty in cleaning... What benefits?


Dolomieu said:
Jaybird made the mason jar toppers to help me deal with suck back. I'm not saying it's going to keep 100% of the air out but with the batches I have used it on so far, there has been zero suck back. I thought the fluid may suck back into the second mason jar when cold crashing, but I haven't had that happen yet.
Click to expand...

That rig will help prevent sucking back your airlock solution, but it won't help prevent sucking oxygen into the fermenter on cold-crashing. Also, as I crash down to 0c (32f) the sanitizer will likely freeze solid, hence my bag solution above.
 
Jtk78 said:
It may not suck the liquid back, but it will suck air right through the two bubbles, correct? What I'm trying to prevent is the introduction of air to the carboy. I also don't buy CO2 in the carboy acts as a protective blanket from the new air.
Click to expand...

And what happens when you pull the balloon off? It sucks air into the carboy. Only way to prevent 100% exposure to air is to cold crash in a pressure-rated vessel like a corny keg so as the liquid and gas cool and reduce in volume, there's a feed of CO2 to replace it.
 
Not necessary to have a pressure rated vessel. See my example above. This will work with a carboy, and should work well on Spidels, too.

Buckets? Maybe but the lid seal is not really reliable on them, so YMMV.
 
As was pointed out in another thread on this topic, the biggest source of suck-back during cold crashing is the increased solubility of CO2 at lower temperature (if you give it time to reach equilibrium). I put together a little spreadsheet that lets you see how much you'll suck back here - it's surprisingly high! It also shows how long a blow-off tube you'd need (for a given diameter) not to suck liquid all the way back to the fermenter.

The tap attachments on Speidels turn out to be a handy way of attaching a balloon full of C02 during cold-crashing - and the tap makes it easy to refill them without introducing any air to the system.

15844601_1819450968297167_8295597276350302016_o.jpg
 
The_Bishop said:
That rig will help prevent sucking back your airlock solution, but it won't help prevent sucking oxygen into the fermenter on cold-crashing. Also, as I crash down to 0c (32f) the sanitizer will likely freeze solid, hence my bag solution above.
Click to expand...

We make compromises in our efforts. Plastic is also permiable, so your solution, while perfect for you, can have fault found. While mine is admittedly not perfect, it fits my needs and thus thought I would share. I to crash to 32 and a little salt in the sanitizer solution solves that issue. Also I have never seen air bubble back in to the conicals, so your concern, while valid, isn't as large of an issue as you may think.
 
motosapiens said:
are you having problems with oxidation in your beer? or is this just an OCD theoretical concern?

i've never had a problem, so I just cold-crash overnight to 40-50 degrees (whatever the garage is at in the winter), and don't worry about it. That's enough to get all the dry hops to drop to the bottom.

sure, maybe some air gets in there.... big deal. it's going to get exposed to air when I bottle too.
Click to expand...


To answer this, I've not noticed any oxidation issues. I do not keg, or have the equipment nor desire to right now. (Blasphemy, I know) Although I do have CO2 tank and a regulator.

What I have had happen is my 7 gallon Fermonster starting to cave in during crashing it. I also have had some Star San get sucked in. I thought if there was a relatively easy was prevent the cave in / Star San suck in / extra oxygen introduction I would try it.
 
I didn't notice how bad of an oxidation issue I had until I switched to corny kegs and spunding.

Corny kegs make it possible to pull gravity samples without opening the vessel. When i'm within a few points of terminal gravity I rack under a closed system to a keg that was purged with the fermentation gases. The yeast consume whatever little bit of oxygen is introduced in that step while they finish the last little bit of sugar, which also naturally carbonates.

Air has A LOT of oxygen. Even a shot glass size volume of "air" into a corny keg is enough to bring it above what is typically considered a detectable threshold.

Corny kegs aren't any harder to clean that a carboy either. Build yourself the right cleaning rig and it'll take care of cleaning itself spotless.

Fermenting under pressure also collapses kraussen. At 3.5 psi i literally get 1cm of kraussen... thus i can fill a keg up past the top weld and not even get any blow off.
 
schematix said:
I didn't notice how bad of an oxidation issue I had until I switched to corny kegs and spunding.
Click to expand...

i guess I need to taste an officially oxidized beer. I do know that I like my beer better than pretty much anything i can purchase in a bottle or can, and I like it better than most draft beers at breweries, but that's probably because I only brew stuff I like. I have certainly never noticed any off-flavors to develop down the road after bottling.

I suspect however, that bottle-conditioning in itself is somewhat helpful about cleaning up stray oxygen.

I liked the bag of co2 idea posted earlier. At some point after I get water chemistry more dialed perhaps I'll look into it. I am generally of the opinion that I only need to solve brewing problems I can detect with my tastebuds, but as schematix notes, sometimes you don't know you have a problem until you fix it while solving some other problem.

but people have been brewing good beer without balloons for at least 1000 years....
 
Moderate oxidation doesn't outright ruin beer. Let's be very very clear about it. But it does have an impact.

Whether you know what to taste for or not doesn't change the fact that there the beer may be oxidized and you may like it! That's fine. It's also not so much a flavor like esters, phenolics, acetaldehyde, diacetyl, etc. It's more of a brightness and fullness. I thef entire process is conducted without oxygen, there is an additional set of flavors that is completely absent in home brew because the mashes are all oxidized with the widely published procedures.

Nearly all craft pub beer i've ever had is oxidized. Even a lot of the stuff packaged by microbreweries is oxidized. It can still taste good, but it may not have been as good as it was or could have been. This is especially true of IPAs.

Bottle conditioning does offer protection against oxidation, but only if it's bottled before oxidation sets in. Active fermentation will consume nearly all oxygen.
 
"Elitist?" That's a new one. Just remember, just because you don't think it's there doesn't mean it isn't.

If we keep going like this, LoDo is going to become the new "Glass Carboy."
 
I mean 'Elitist' in regards to the statements that 'all the beer I have ever tasted that wasn't mine was oxidized.'

I'm not saying that beer doesn't get oxidized. I'm saying that the LoDo folks carry it too far.

And that'll be enough of this thread hijack.
 
Oh, yes, you are correct, that could smack of snobbishness (no offense, schematix), but again if it's an off flavor that you don't like and can get rid of, why not?

Back on topic! I meant to post someone else's brilliant design, but I couldn't remember their username or find the thread. Helpful, right? Anyway, as I remember, it was a carboy cap rigged with a co2 qd and a balloon on a tee. Basically, they could put 1 or 2 psi on to keep everything equalized, and the ballon was just a safety valve of sorts. Pretty nifty.
 
The_Bishop said:
Ok, enough with the elitist LoDo prothletising. It's getting old.
Click to expand...

Who said LoDo? You're the only one who has mentioned it in this thread.

We were discussing a very real concern about cold crashing in a carboy, which is sucking in atmospheric air, believed to cause oxidation. If you don't believe in oxidation, then why even try to prevent it with various contraptions?
 
Who the hell said I don't believe in it?

I absolutely think it's something that needs to be controlled post ferment, and something to pay attention to elsewhere in the process. However, some of the 'solutions' offered up are getting a bit out of hand, along with claims that 'every beer I ever had was oxidized!'

As for the rest? I'll just leave this here:
schematix said:
1. Lower ABV = better beer

2. Low Oxygen = great. Telling everyone about LoDO and watching them flip their shat = priceless.
Click to expand...
 
afro_lou said:
...Back on topic! I meant to post someone else's brilliant design, but I couldn't remember their username or find the thread. Helpful, right? Anyway, as I remember, it was a carboy cap rigged with a co2 qd and a balloon on a tee. Basically, they could put 1 or 2 psi on to keep everything equalized, and the ballon was just a safety valve of sorts. Pretty nifty.
Click to expand...

I'm pretty sure you are referring to day_trippr's solution, but I'm not sure what thread he put it in. I'll have to take a look around...

Edit: Here's one of his posts about it Cold Crashing
 
The_Bishop said:
Who the hell said I don't believe in it?

I absolutely think it's something that needs to be controlled post ferment, and something to pay attention to elsewhere in the process. However, some of the 'solutions' offered up are getting a bit out of hand, along with claims that 'every beer I ever had was oxidized!'

As for the rest? I'll just leave this here:
Click to expand...



You're taking 2 of my comments out of context.

1. My comment about all beer being oxidized is not what I said. I was referring to micro brew pub beer.

2. That LoDO quote was from another thread. In this thread we weren't talking about LoDO, which has a hot side component not being discussed here.
 
The_Bishop said:
Here's what I've been doing for a year or so now.

After primary ferment is over and I'm getting ready to cold crash, I'll attach a bag filled with CO2 to the fermenter. Anything it's pulling into the fermenter is CO2.

This is on my conical. You can use the same thing in a carboy, just put the tube into a bung. The bag I use on my conical is a 2 gallon ziplock. To attach the tubing, I'll cut a small part of the corner off, just enough to make a hole that's a bit smaller than the tubing, then push the tubing through from the inside. Seal with a wrap or two of high quality electrical tape on the outside.

It's cheap and easy, and it minimizes O2 pickup.
Click to expand...

In your experience, about how much of the 2 gallons is displaced during fermentation? Do you ever have to charge more co2 into the bag? I'm debating using your method or just pressure transferring into a purged corny before I cold crash and dry hop. I'm doing a huge DIPA with majority of the hops coming in the dry hop, so I want to prevent all air exposure.
 
On cold crash? The bag usually drops by about 1/2 or so.

So far so good, haven't had any post-ferm oxidation and some of my kegs, especially the high-gravity stuff, last 1-2 months.
 
Dolomieu said:
Jaybird made the mason jar toppers to help me deal with suck back. I'm not saying it's going to keep 100% of the air out but with the batches I have used it on so far, there has been zero suck back. I thought the fluid may suck back into the second mason jar when cold crashing, but I haven't had that happen yet.
Click to expand...


This is the winner for me. I'm gonna build these.

I can imagine what to do but what do I need for the fittings through the mason lids?
 
oceanic_brew said:
This is the winner for me. I'm gonna build these.

I can imagine what to do but what do I need for the fittings through the mason lids?
Click to expand...

http://www.norcalbrewingsolutions.com/store/Krausen-Catcher-4-Nipples.html

http://www.norcalbrewingsolutions.com/store/Krausen-Catcher-2-Nipples-Grommet.html

There are threads​ with diy versions​, but I had Jay make those for me because the diy versions were clunky and I was having trouble improving on the design. Then he started the one off part thread and these were born.
 
The rate of the oxidation reaction doubles (or halves) for every 10°C (18°F) change in temperature. So at 35°F in cold crashing, the rate of oxidation is 1/4 that of the room temperature exposure the beer sees when cooling, filling the fermenter, the 6-12 hours before active fermentation, and at bottling. The oxidation rate at cold crash is at 1/1000th the rate at boiling temperatures, but during boiling the surface of the wort is mostly protected by a layer of steam. This is not so, however, during the cool down and handling process when the wort is falling from say 150°F to ambient.

Furthermore, 5 gallons of beer at fermenting temperature only shrinks 0.15% in cooling to cold crashing temperature, so only about (0.0025 gallons) or one ounce of air should get sucked in.

Me thinks folks worry too much about oxidation.

TomVA
 

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