Cold crashing problems and questions!!!

[BrewinSoldier]

Hey guys! This is the second batch of beer in a row I have ruined. The first was my fault. I forgot to pull the blow-off tube out of the sanitizer water when taking a sample and it sucked up half a mason jar or sanitizer water into my $120 batch of Pliny the Younger clone. I was sooooooooo bummed but it was my own fault. Anyways, I went to counseling and have moved past it..lol

Fast forward to yesterday. I had a blueberry wheat I have been messing with the recipe on that I had in the conical. It was done fermenting so I decided it was time to crash cool it with my glycol chiller. Crank the temp down to 34 degrees around 5pm, and leave for the night. We get back at around 3am, low and behold, the damn thing sucked down a whole mason jar full of sanitizer via the blow-off tube.

How am I supposed to crash cool for 48 hours if I can't leave the blow-off tube in there? If I leave it out, it will suck in oxygen for 48 hours. The only option I can think of from now on so this doesn't happen again is to hook up a line of co2 at about 2psi so it will suck that in if it needs it rather than the oxygen.

How do you guys prevent that from happening?

 

[DrMaltyVonHopenstein]

I don't think that I would toss a batch because of a little sanitizer in the mix.

How much sanitizer would be too much? Anybody?

*Edit: I do not bother cold crashing in large part because of the oxidation concern.

 

[day_trippr]

 

[seabrew8]

I just put water in my airlocks, easy peasy and no worrying about suck back. However, i wouldn't worry to much about a little starsan.

Besides you have alcohol now just fill it with some boiled water the yeast is finished its job.

 

[whoaru99]

Yup, I've done it a couple times myself...forgot the blowoff tube and cold crashed, getting a quart or two of suckback.

When the fermentation starts to slow, pull the blowoff tube and use a bubbler airlock like pictured. I usually fill mine with vodka, sometimes Starsan solution.

We drank both batches of suckback beer. Didn't have any complaints.

 

[jddevinn]

Positive pressure is the only way to do this correctly.

If you put one of the S airlocks in you are either going to 1. create a vacuum in the fermenter 2. pull air in through other leaks.

 

[IslandLizard]

Are you telling us you dumped your $120 Pliny the Younger clone over a bit of Starsan?

If you don't want air infiltrating, your blow off tube/jar won't prevent that either. And as you already noticed, cold crashing with a blow-off jar is a no-no. You could use a very low pressure of CO2, a "balloon" filled with CO2, or some other method that keeps air out while the beer volume is contracting. Or not sweat it, and live with a little O2 exposure.

I put a 2x folded over Starsan soaked washcloth over my lid's grommet hole, and refresh it once or twice a day.

 

[slym2none]

Are you telling us you dumped your $120 Pliny the Younger clone over a bit of Starsan?

That's what I got out of that.

 

[kevink]

I use a low pressure propane regulator which puts 0.4 psi on the fermenter during crashing. Nothing goes in but CO2.

 

[TAK]

Don't cold crash?

I ferment in an oversized corny. I don't find the need to cold crash most often. Though when I have, removing the blowoff and using low CO2 pressure seems like the only way to go. Many of the methods above guarantee introduction of O2, and in cold beer that's going to absorb more gas anyway because of the low temps, man, I can't even stomach the thought. Ok, it's probably not a huge deal for your wheat beer, but for a batch with enough hops to foot a bill of $120, no way I want those hops seeing any air until it hits my glass.

 

[day_trippr]

Positive pressure is the only way to do this correctly.

If you put one of the S airlocks in you are either going to 1. create a vacuum in the fermenter 2. pull air in through other leaks.

What?

You do realize that the S-lock is hollow, right?

Cheers!

 

[Pkrd]

A suction canister in between carboy and blowoff jar would solve both the suckback and oxygen issue.

 

[jddevinn]

What?

You do realize that the S-lock is hollow, right?

Cheers!

I have actually never used one of these?!?! So there is airflow through the airlock? Then what is the point of calling it an airlock? Is it supposed to "sanitize" the air because it passes through the liquid in the lock?

 

[Pkrd]

I have actually never used one of these?!?! So there is airflow through the airlock? Then what is the point of calling it an airlock? Is it supposed to "sanitize" the air because it passes through the liquid in the lock?

Its one way (until you cold crash), then it's the other way.
[ame]https://www.youtube.com/watch?v=DV_9tfFyY00[/ame]

 

[CamG]

I have actually never used one of these?!?! So there is airflow through the airlock? Then what is the point of calling it an airlock? Is it supposed to "sanitize" the air because it passes through the liquid in the lock?

The purpose of the air lock is to let the flow out of the fermentor and not in.
When cold crashing there is reverse pressure so oxygen will flow back into the beer.
Sure it may go through starsan and be sanitized but it's still oxigen going back in.

 

[IslandLizard]

A suction canister in between carboy and blowoff jar would solve both the suckback and oxygen issue.

How does this solve oxygen issues?

 

[Pkrd]

How does this solve oxygen issues?

It fills up with CO2 while fermenting. When cold crashing it sucks in your sanitiser but not any oxygen.

 

[BigFloyd]

The purpose of the air lock is to let the flow out of the fermentor and not in.
When cold crashing there is reverse pressure so oxygen will flow back into the beer.
Sure it may go through starsan and be sanitized but it's still oxigen going back in.

I'm not sure where folks get the idea that using an s-airlock during cold crashing is going to going to bring enough O2 into a primary fermenter to cause an oxidation issue.

Unless you've been popping the lid off to mess with it too much, there's a lovely bit of CO2 sitting in that headspace. The small amount of air (78% nitrogen) introduced via crashing with an s-lock isn't going to somehow worm its way into solution and ruin your brew.

I cold crash all of my batches with StarSan in an s-airlock at 35*F at least 5 days. Months later (a couple times over a year), there's never been any hint of oxidation whatsoever.

 

[kevink]

It fills up with CO2 while fermenting. When cold crashing it sucks in your sanitiser but not any oxygen.

It won't work too well if you have blow-off. It will fill with foam, liquid, and yeast which can then get sucked back into the fermenter during crashing, depending on how full it got. That's a little too weird for me. What comes out of the fermenter stays out of the fermenter. And how do you know that all of the oxygen will get purged out of that container during fermentation? Some O2 will get sucked in if it's not all purged out.

 

[DurtyChemist]

Hey guys! This is the second batch of beer in a row I have ruined. The first was my fault. I forgot to pull the blow-off tube out of the sanitizer water when taking a sample and it sucked up half a mason jar or sanitizer water into my $120 batch of Pliny the Younger clone. I was sooooooooo bummed but it was my own fault. Anyways, I went to counseling and have moved past it..lol

Fast forward to yesterday. I had a blueberry wheat I have been messing with the recipe on that I had in the conical. It was done fermenting so I decided it was time to crash cool it with my glycol chiller. Crank the temp down to 34 degrees around 5pm, and leave for the night. We get back at around 3am, low and behold, the damn thing sucked down a whole mason jar full of sanitizer via the blow-off tube.

How am I supposed to crash cool for 48 hours if I can't leave the blow-off tube in there? If I leave it out, it will suck in oxygen for 48 hours. The only option I can think of from now on so this doesn't happen again is to hook up a line of co2 at about 2psi so it will suck that in if it needs it rather than the oxygen.

How do you guys prevent that from happening?

Cold crash slower. Do 5 degrees at a time. When it hits the temp you have set drop it another 5. It may take longer but apparently everyone is concerned with sucking air lock liquid into their beer and the solution is always to do it slower. Once your beer hits your cold crash temp it can be held there longer if you want. I've recently decided on 5F temp changes before I go to work then lowering the temp more if it's already there when I get home at the end of the day. It's easy to drop 10 degrees in a day this way.

 

[kevink]

The small amount of air (78% nitrogen) introduced via crashing with an s-lock isn't going to somehow worm its way into solution

If there's any O2 in the headspace, the O2 will evenly mix with the CO2. It doesn't matter that CO2 is more dense than what gets sucked in. The molecules bounce around and all of the gasses will evenly mix. You then have O2 in contact with the beer. It sounds like the OP is trying to eliminate all O2 exposure. An S shaped airlock isn't going to do what he wants.

 

[kevink]

Cold crash slower. Do 5 degrees at a time. When it hits the temp you have set drop it another 5. It may take longer but apparently everyone is concerned with sucking air lock liquid into their beer and the solution is always to do it slower. Once your beer hits your cold crash temp it can be held there longer if you want. I've recently decided on 5F temp changes before I go to work then lowering the temp more if it's already there when I get home at the end of the day. It's easy to drop 10 degrees in a day this way.

He wants to prevent O2 from getting sucked in. How is crashing slower going to prevent O2 from getting sucked in? The loss in volume has to be made up somehow.

 

[jddevinn]

Its one way (until you cold crash), then it's the other way.
https://www.youtube.com/watch?v=DV_9tfFyY00

Ah I always used the other style airlocks when I had carboys. Makes since.... I would still prefer not to introduce air into the fermenter.

I'm not sure where folks get the idea that using an s-airlock during cold crashing is going to going to bring enough O2 into a primary fermenter to cause an oxidation issue.

Unless you've been popping the lid off to mess with it too much, there's a lovely bit of CO2 sitting in that headspace. The small amount of air (78% nitrogen) introduced via crashing with an s-lock isn't going to somehow worm its way into solution and ruin your brew.

I cold crash all of my batches with StarSan in an s-airlock at 35*F at least 5 days. Months later (a couple times over a year), there's never been any hint of oxidation whatsoever.

Co2 "blanket" is always brought up in these discussions. There is no Co2 blanket. Mixture by enthalpy will result in the Co2 diffusing into the air very quickly. Even without any chemistry knowledge....if Co2 didn't diffuse in the air why doesn't our breath cause a Co2 "blanket" to form in spaces with large amounts of people?

 

[kevink]

You just had to say the "B" word. I hate that "B" word! Sounds like you do, too.

 

[DurtyChemist]

He wants to prevent O2 from getting sucked in. How is crashing slower going to prevent O2 from getting sucked in? The loss in volume has to be made up somehow.

Crashing slower will minimize the amount of oxygen absorbed because it will keep his air lock full and prevent oxygen from getting into the beer. The air lock works both ways. When you cold crash really quick it will suck in air like a vacuum. With a cool controlled temperature reduction you'll minimize it because dropping temps slowly will be just like lagering and a slow drop in temp will minimize the vacuum. Slower temp drops will let the vacuum stop then restart vs continually pull in air from outside. When the volume is made up over time it won't actually allow oxygen in because the liquid in the air lock will do its job.

 

[kevink]

Crashing slower will minimize the amount of oxygen absorbed because it will keep his air lock full and prevent oxygen from getting into the beer. The air lock works both ways. When you cold crash really quick it will suck in air like a vacuum. With a cool controlled temperature reduction you'll minimize it because dropping temps slowly will be just like lagering and a slow drop in temp will minimize the vacuum. Slower temp drops will let the vacuum stop then restart vs continually pull in air from outside. When the volume is made up over time it won't actually allow oxygen in because the liquid in the air lock will do its job.

I don't think so. If you crash slow and air doesn't pull in through the airlock, it just means you have air leaks somewhere else and air is getting in through them instead of the air lock. You will have the exact same amount of vacuum or reduction in volume from contraction regardless of how fast you drop the temp. So, crashing slow will actually harm the beer more since the O2 will be in the headspace for a longer period of time!

 

[BigFloyd]

Ah I always used the other style airlocks when I had carboys. Makes since.... I would still prefer not to introduce air into the fermenter.



Co2 "blanket" is always brought up in these discussions. There is no Co2 blanket. Mixture by enthalpy will result in the Co2 diffusing into the air very quickly. Even without any chemistry knowledge....if Co2 didn't diffuse in the air why doesn't our breath cause a Co2 "blanket" to form in spaces with large amounts of people?

Please don't misinterpret. I never said the CO2 "B word" since I don't believe that especially over-used term accurately describes the conditions inside the headspace of an undisturbed primary fermenter. One does, however, by the finishing stages of fermentation have a much, much higher concentration of CO2 than the <1% found in the environment because of the quantity generated inside the vessel.

You may be aware that some breweries (and a handful of homebrewers) will, towards the end of active fermentation, replace the blowoff pipe/hose with a regulator to place the headspace under pressure in order to naturally carbonate the beer. Franconia Brewing (owned by German master brewer Dennis Wehrman) uses this process. If there was a significant amount of O2 remaining in the headspace, they couldn't do it without causing oxidation.

Exhaled CO2 (and that produced by plants at night or combustion) into the environment is more dense than nitrogen and oxygen, but not by that much. It's easily diffused due to air currents or, to a smaller extent by diffusion of gases principles and Brownian movement. Not really an accurate analogy.

 

[day_trippr]

[...]The only option I can think of from now on so this doesn't happen again is to hook up a line of co2 at about 2psi so it will suck that in if it needs it rather than the oxygen.[...]

My solution...







Cheers!

 

[disney7]

I used KevinK's method of using a water column natural gas regulator (0.4 psi) and it works fine if you want a cheap solution.

I was worried that if my fermenter valve ever started leaking during a cold crash, the positive pressure would force all the beer out.

Now I use a cask breather. They're designed to only provide CO2 when a vacuum is present, so they supply low pressure CO2 at the same rate the fermenter is demanding it.

The only downside is they're a bit expensive. I got mine for $70 from UKBrewing.com

 

[Gavin C]

This is what I do now



This is what I used to do before the penny dropped




I make no effort to prevent air inflow. @Day_trippr 's solution is still the best one I've ever seen on HBT to address this issue.

 

[kevink]

I used KevinK's method of using a water column natural gas regulator (0.4 psi) and it works fine if you want a cheap solution.

I was worried that if my fermenter valve ever started leaking during a cold crash, the positive pressure would force all the beer out.

Now I use a cask breather. They're designed to only provide CO2 when a vacuum is present, so they supply low pressure CO2 at the same rate the fermenter is demanding it.

The only downside is they're a bit expensive. I got mine for $70 from UKBrewing.com

A foot of beer alone above your valve will put about 0.4 psi on it. If it were going to leak, you'd probably already know it. What type of valve were you concerned about leakage with?

 

[jddevinn]

Crashing slower will minimize the amount of oxygen absorbed because it will keep his air lock full and prevent oxygen from getting into the beer. The air lock works both ways. When you cold crash really quick it will suck in air like a vacuum. With a cool controlled temperature reduction you'll minimize it because dropping temps slowly will be just like lagering and a slow drop in temp will minimize the vacuum. Slower temp drops will let the vacuum stop then restart vs continually pull in air from outside. When the volume is made up over time it won't actually allow oxygen in because the liquid in the air lock will do its job.

A "vacuum" will be created because of the difference in volume of the gas above the beer as the temperature drops. Changing the temps slower will reduce the flow rate of air through the airlock but will not reduce the volume differential between the two conditions, and therefore will not reduce the final volume of air pulled through the airlock.

 

[jddevinn]

Please don't misinterpret. I never said the CO2 "B word" since I don't believe that especially over-used term accurately describes the conditions inside the headspace of an undisturbed primary fermenter. One does, however, by the finishing stages of fermentation have a much, much higher concentration of CO2 than the <1% found in the environment because of the quantity generated inside the vessel.

You may be aware that some breweries (and a handful of homebrewers) will, towards the end of active fermentation, replace the blowoff pipe/hose with a regulator to place the headspace under pressure in order to naturally carbonate the beer. Franconia Brewing (owned by German master brewer Dennis Wehrman) uses this process. If there was a significant amount of O2 remaining in the headspace, they couldn't do it without causing oxidation.

Exhaled CO2 (and that produced by plants at night or combustion) into the environment is more dense than nitrogen and oxygen, but not by that much. It's easily diffused due to air currents or, to a smaller extent by diffusion of gases principles and Brownian movement. Not really an accurate analogy.

I don't see how this relates? Fermenting under pressure is the opposite of what we are talking about here. Yes if we close the system the Co2 concentration will rise; if the system is not closed it will not rise as it is diffused to the atmosphere even without physical mixing of the gases.

Air currents are not required for diffusion. In a closed system the enthalpy of the gases will cause mixture.

*source: mechanical engineering and physics degrees

 

[Izzie1701]

Cold crash slower. Do 5 degrees at a time. When it hits the temp you have set drop it another 5. It may take longer but apparently everyone is concerned with sucking air lock liquid into their beer and the solution is always to do it slower. Once your beer hits your cold crash temp it can be held there longer if you want. I've recently decided on 5F temp changes before I go to work then lowering the temp more if it's already there when I get home at the end of the day. It's easy to drop 10 degrees in a day this way.

Lowering it slower won't do anything. You still have the same loss of volume weather you chill it over 100 days or 1 hour. Your rate of volume change is not affected by time at all. It's the thermal expansion law formula that's to hard to type in here.

 

[BrewinSoldier]

Thanks for all the responses and input guys. And yes you read right about the tossing of the Pliny the younger clone. It sucked up a big ol mason jar full of the water, and with only 4.5 gallons in the fermenter, I didn't want off tastes. I was contemplating dumping it anyways because I tried something different with the water this time around to get the PH down and I think I had to add wayyyy too much phosphoric acid 10% to get it down the way this book said. It sucked but lesson learned.

I really like the casket breather idea. That sounds like it would be the best option and would do exactly what I need. Overkill? Maybe, but aren't we all after making our beer taste the best we possibly can? Lol

 

[kevink]

Either a cask breather or a low pressure propane regulator will do exactly what you want. One will not make better tasting beer than the other, but one is significantly cheaper. The low pressure regulator I used was somewhere around $13.

 

[IslandLizard]

Thanks for all the responses and input guys. And yes you read right about the tossing of the Pliny the younger clone. It sucked up a big ol mason jar full of the water, and with only 4.5 gallons in the fermenter, I didn't want off tastes. I was contemplating dumping it anyways because I tried something different with the water this time around to get the PH down and I think I had to add wayyyy too much phosphoric acid 10% to get it down the way this book said. It sucked but lesson learned.

I really like the casket breather idea. That sounds like it would be the best option and would do exactly what I need. Overkill? Maybe, but aren't we all after making our beer taste the best we possibly can? Lol

In the past I've had some good pint size suck backs into 5 gallon batches, and honestly, I could not tell it was there, no matter how hard I tried. If anything it was the suggestion, knowing it was there, I should be able to taste it. Bupkis! I had others taste it, and aside from some other flaws they pointed out, the unintended Starsan plunge was not one of them. Even the dilution was not detectable.

This brings me to the next question. How many brews have you done so far? How were they? Except from those few people with undisputed innate talent, none of us were born brewers, we all need to learn. We keep making mistakes left and right in the hope one day we master the process enough and minimize our errors.

So I brewed this marvelous Centennial IPA, huh. Tasted great out of the cold crashed bucket. No suck back, we learned fast. Put it in the keg for force carbonation and start rolling for 10 minutes... :smack: I had forgotten to purge the headspace! OK, we're gonna drink it, it's summer, will go fast...

...Within 2 weeks I noticed the beer had gotten darker and darker and started to taste and smell less hoppy, while weird flavors started to come through. Let me tell you, that last gallon was hard to finish. But what I learned was invaluable!

 

[MannyEdwards]

Just put a sanitizer - soaked sponge over the inlet and hold it on with foil. Even if a quart or two of air gets sucked in, it will never touch the beer, because it's lighter than the co2 in the fermenter.

 

[Gavin C]

Just put a sanitizer - soaked sponge over the inlet and hold it on with foil. Even if a quart or two of air gets sucked in, it will never touch the beer, because it's lighter than the co2 in the fermenter.

Unfortunately gasses of different densities do not behave this way. Any air that is sucked in will mix and become evenly distributed with the CO2 rich fermentor headspace gas.

If gasses did behave this way there would be a nice blanket of CO2 in the lower layers of our atmosphere. Life as we know it would not exist.

 

[AZCoolerBrewer]

I would think that more o2/contaminants would contact the beer during bottling than the little burp of air from cold crashing.