CRASH COOLING SUCK BACK ISSUES SOLVED. C02 Reservoir for your fermenters

[Jaybird]

We have had a boatload of questions and comments about the Krausen Catchers being used for a 3 pc airlock and using the first jar as a Co2 reservoir. I am personally using 1/2 gallon mason jars and I really am happy with it.
Hers is a little video we did showing how I am using it and how to put it together.

SORRY IT'S MY UGLY MUG YOU HAVE TO SEE...LOL Our smoken hot Redhead was on vacation...

Cheers
Jay


[ame]https://www.youtube.com/watch?v=efVPBIzadko[/ame]

 

[woo_pig]

You should call it a triple chambered airlock.

 

[isomerization]

"WE ALSO OFFER COMPLETE Jaybird™ Ultimate Krausen Catcher Kits in 16, 32, and 64 ounce sizes. These expanded kits include the canning jar, screw lid, and 2 feet of 1/2" tubing. Simply search for “Krausen Catcher” in our online store."

I am not seeing this kit online, can you provide a link? Thank you.

 

[Morrey]

Every time I call, NorCal's "Smokin' Hot Redhead" is unavailable and I end up talking with Jaybird. DARNNNNN

I did get the lids JayBird offers and made up the system with 1/2 gallon Mason Jars I got at WalMart. They had these jars for sale individually so I only needed two. I had some 1/2" silicone tubing and all else was easy to manage. I didn't find the complete kit he mentioned on his website.

I have the system in operation now with an active fermentation going in my glycol cooled Ss FTSs Brew bucket. When I crash next week I'll stick close and see the airlock in action. Previously, with this chiller crashing I went from 65F down to 35F in just a tick over an hour. With this rapid cooling cycle, I sucked back darn near 1/2G of Starsan....live and learn. But this new airlock system is going to allow rapid cooling to happen with no suck back of sanitizer into fermenter.

Some folks seem critical to go to these lengths to prevent outside air from being drawn in to the fermenter. I suppose it is a fault of mine to want to do things that I determine to be "the right way". Thanks Jaybird for responding so quickly. Tell the Smokin' Hot Redhead I said hello!

 

[doug293cz]

If you really want to "harvest" the CO2 for a useful purpose, get a third jar with a 4 nipple lid and connect it to the fermenter. No interior tubes or liquid in this jar. The output of this jar goes to the liquid post of a keg (pre-sanitized.) Gas post of keg gets connected to the two jar arrangement shown by jaybird. At the end of fermentation the keg will be filled with CO2 at single digit ppb (yes parts per billion) O2, and is ready for a low O2 closed transfer. See the analysis here. If you are doing 10 gal batches, just string two kegs in series; 15 gal batches - 3 kegs, etc.

Brew on

 

[Jaybird]

"WE ALSO OFFER COMPLETE Jaybird™ Ultimate Krausen Catcher Kits in 16, 32, and 64 ounce sizes. These expanded kits include the canning jar, screw lid, and 2 feet of 1/2" tubing. Simply search for “Krausen Catcher” in our online store."

I am not seeing this kit online, can you provide a link? Thank you.

Ok that is actually being removed ONLY because it was put there out of order. We do sell the jars and will have the kits available soon (next week or so) but till then we are ONLY selling the KIT without jars. IF YOU NEED JARS....CALL ME! I'll hook you up and we can figure out the shipping cost. As it is the KIT were offering right now can ship first class at the cost of about $3

Every time I call, NorCal's "Smokin' Hot Redhead" is unavailable and I end up talking with Jaybird. DARNNNNN

I did get the lids JayBird offers and made up the system with 1/2 gallon Mason Jars I got at WalMart. They had these jars for sale individually so I only needed two. I had some 1/2" silicone tubing and all else was easy to manage. I didn't find the complete kit he mentioned on his website.

I have the system in operation now with an active fermentation going in my glycol cooled Ss FTSs Brew bucket. When I crash next week I'll stick close and see the airlock in action. Previously, with this chiller crashing I went from 65F down to 35F in just a tick over an hour. With this rapid cooling cycle, I sucked back darn near 1/2G of Starsan....live and learn. But this new airlock system is going to allow rapid cooling to happen with no suck back of sanitizer into fermenter.

Some folks seem critical to go to these lengths to prevent outside air from being drawn in to the fermenter. I suppose it is a fault of mine to want to do things that I determine to be "the right way". Thanks Jaybird for responding so quickly. Tell the Smokin' Hot Redhead I said hello!

You bet! Absolutely my pleasure! Keep me posted...

Here is a picture of her so you know who your talking to NEXT TIME you call... Baaahhhhaaaaaaa

Cheers
Jay

 

[Jaybird]

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

Here is the kit without the jars..

Cheers
Jay

 

[isomerization]

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

Here is the kit without the jars..

Cheers
Jay

Ok quick question, ordered earlier today (#14100). The kit wasn't live so just went with the 2 lids and some tubing. The way the lids are described, it sounds like the grommets are included, is this true? If not, well guess the parts I ordered won't work very well, lol. Either way it would be great to get the kit pricing as that is cheaper than what I paid. If this is possible, I can call and talk with someone, thanks!

EDIT: problem solved, thanks!

 

[Jaybird]

EDIT: problem solved, thanks!

Cheers
Jay

 

[Morrey]

Jay,

After seeing the Red Head I am sending my resume. Don't worry about paying me to work there...I'll pay YOU.

I noted in the kit description you use 3/8" ID tubing. I used 1/2" which fits fine but not seeing active gas bubbles in the jar with the airlock. The hose seems fairly loose on the nipples.....should I see off gassing in the starsan on jar 2 or is it normal not to see anything. I did note the liquid in the S airlock is displaced like it is off gassing but no bubbling. Do I have leaks or is this normal?

 

[Jaybird]

Yeah. No need for the resume @Morrey . Just show up on time, ready to work. LOL

You should see bubbles IN the second jar as they pass through the first. You are probably leaking. I am only using 3/8 because I am using silicone tubing and it nice and snug. If you are loose then just a few ty wraps or zip ties will do the trick.

Cheers
Jay

 

[beernutz]

Pardon me if this is a stupid question but what happens when all the liquid in the jar with the airlock is sucked back into the other jar? If you are cold crashing and this happens wouldn't air be sucked into the airlock jar and then once the water is gone subsequently sucked into the other jar and possibly into the fermenter?

 

[doug293cz]

Pardon me if this is a stupid question but what happens when all the liquid in the jar with the airlock is sucked back into the other jar? If you are cold crashing and this happens wouldn't air be sucked into the airlock jar and then once the water is gone subsequently sucked into the other jar and possibly the fermenter?

The trick is to make sure that the volume of liquid in the second jar is larger than the volume of gas that will suck back into the fermenter. The volume of gas that will suck back can be calculated as follows:

Suck_Back_Vol = Ferm_Headspace_Vol * (1 - (Min_Temp + 273.15) / (Max_Temp + 273.15)) [for temp in °C]
Suck_Back_Vol = Ferm_Headspace_Vol * (1 - (Min_Temp + 459.67) / (Max_Temp + 459.67)) [for temp in °F]​

Obviously, the mason jars used have to have a larger volume than calculated by the equations above.

Brew on

 

[beernutz]

The trick is to make sure that the volume of liquid in the second jar is larger than the volume of gas that will suck back into the fermenter. The volume of gas that will suck back can be calculated as follows:

Suck_Back_Vol = Ferm_Headspace_Vol * (1 - (Min_Temp + 273.15) / (Max_Temp + 273.15)) [for temp in °C]
Suck_Back_Vol = Ferm_Headspace_Vol * (1 - (Min_Temp + 459.67) / (Max_Temp + 459.67)) [for temp in °F]​

Obviously, the mason jars used have to have a larger volume than calculated by the equations above.

Brew on

So fermenting 10 gallon (37.8L) batches in my 60L Speidel I assumed

22.2L or ~1350 cubic inches of fermenter headspace
33 min temp
66 max temp
and calculated ~85 cubic inches of suck back volume

Since a quart Mason jar holds ~58 cubic inches I need something bigger to hold water?

 

[isomerization]

So fermenting 10 gallon (37.8L) batches in my 60L Speidel I assumed

22.2L or ~1350 cubic inches of fermenter headspace
33 min temp
66 max temp
and calculated ~85 cubic inches of suck back volume

Since a quart Mason jar holds ~58 cubic inches I need something bigger to hold water?

I purchased these jars from Walmart (site to store).

 

[doug293cz]

So fermenting 10 gallon (37.8L) batches in my 60L Speidel I assumed

22.2L or ~1350 cubic inches of fermenter headspace
33 min temp
66 max temp
and calculated ~85 cubic inches of suck back volume

Since a quart Mason jar holds ~58 cubic inches I need something bigger to hold water?

Yes. 64 oz (1/2 gal, 115 cu in) mason jars are available (I got mine on Amazon.)

Brew on

 

[Jaybird]

So fermenting 10 gallon (37.8L) batches in my 60L Speidel I assumed

22.2L or ~1350 cubic inches of fermenter headspace
33 min temp
66 max temp
and calculated ~85 cubic inches of suck back volume

Since a quart Mason jar holds ~58 cubic inches I need something bigger to hold water?

I use the 1/2 gallon myself.

Cheers
Jay

 

[Morrey]

I use 1/2 gallon Mason jars too. I found mine in the canning section at Walmart for somewhere around $3 and change each sold individually.

 

[btbnl]

The trick is to make sure that the volume of liquid in the second jar is larger than the volume of gas that will suck back into the fermenter. The volume of gas that will suck back can be calculated as follows:

Suck_Back_Vol = Ferm_Headspace_Vol * (1 - (Min_Temp + 273.15) / (Max_Temp + 273.15)) [for temp in °C]
Suck_Back_Vol = Ferm_Headspace_Vol * (1 - (Min_Temp + 459.67) / (Max_Temp + 459.67)) [for temp in °F]​

Obviously, the mason jars used have to have a larger volume than calculated by the equations above.

Brew on

There's a second (and potentially much larger) effect due to the increased solubility of CO2 in beer as the temperature drops. For instance, for 5G of wort in a 7G fermentor, cold crashing from 70F to 35F you'll see about 0.13G of suck-back from contraction and (assuming you leave long enough to get to equilibrium) another 1.12G from absorption.

There's also a third effect from the contraction of the beer itself, but that's very small in the situations of interest to us.

 

[doug293cz]

There's a second (and potentially much larger) effect due to the increased solubility of CO2 in beer as the temperature drops. For instance, for 5G of wort in a 7G fermentor, cold crashing from 70F to 35F you'll see about 0.13G of suck-back from contraction and (assuming you leave long enough to get to equilibrium) another 1.12G from absorption.

There's also a third effect from the contraction of the beer itself, but that's very small in the situations of interest to us.

Good point about the beer absorption of additional CO2. I forgot to consider that in this case, but I do have a spreadsheet that calculates the additional absorption. My result is even worse than yours. For 20 L of beer, cooled from 20° to 0°C, the additional CO2 absorption amounts to 15 L (about 4 gal), when equilibrium is reached The question is, how long does it take to reach equilibrium?

@Jaybird and @Morrey have been using 1/2 gal reservoirs (I haven't set my system up yet), maybe they can speak to their observations. Have either of you ever emptied the last reservoir of sanitizer due to suck back?

Brew on

 

[Jaybird]

Good point about the beer absorption of additional CO2. I forgot to consider that in this case, but I do have a spreadsheet that calculates the additional absorption. My result is even worse than yours. For 20 L of beer, cooled from 20° to 0°C, the additional CO2 absorption amounts to 15 L (about 4 gal), when equilibrium is reached The question is, how long does it take to reach equilibrium?

@Jaybird and @ Morrey have been using 1/2 gal reservoirs (I haven't set my system up yet), maybe they can speak to their observations. Have either of you ever emptied the last reservoir of sanitizer due to suck back?

Brew on

Yes I have
I only put about 2 cups or so of water in the entire system. Just enough to cover the tubes and a tad bit more. So in reality I have almost a full gallon reservoir there. The first 1/2 gallon coming back into the fermenter would be almost 100% Co2 the last will be a small mixture as you are drawing in air as the airlock unloads. In reality it may be better to FILL the 1 jar to about an inch below the nipple.

Cheers
Jay

 

[Morrey]

Good point about the beer absorption of additional CO2. I forgot to consider that in this case, but I do have a spreadsheet that calculates the additional absorption. My result is even worse than yours. For 20 L of beer, cooled from 20° to 0°C, the additional CO2 absorption amounts to 15 L (about 4 gal), when equilibrium is reached The question is, how long does it take to reach equilibrium?

@Jaybird and @Morrey have been using 1/2 gal reservoirs (I haven't set my system up yet), maybe they can speak to their observations. Have either of you ever emptied the last reservoir of sanitizer due to suck back?

Brew on

I have my 7G Ss BrewTech fermenter (beer ready) scheduled to cold crash this weekend as the first real test. It is currently at 63F, so when I take the chiller down to 35F in one fell swoop...we shall see if the last jar sucks back all the star san into the first jar. Of course the star san can't make it back into the fermenter but I don't want to introduce any O2 into the fermenter even if it is scrubbed by sanitizer. We shall see.....

**Jay, I filled my #2 jar with the airlock about 1/3 full of star san. After I crash Sunday I'll compare notes with you.

 

[btbnl]

I have my 7G Ss BrewTech fermenter (beer ready) scheduled to cold crash this weekend as the first real test. It is currently at 63F, so when I take the chiller down to 35F in one fell swoop...we shall see if the last jar sucks back all the star san into the first jar. Of course the star san can't make it back into the fermenter but I don't want to introduce any O2 into the fermenter even if it is scrubbed by sanitizer. We shall see.....

**Jay, I filled my #2 jar with the airlock about 1/3 full of star san. After I crash Sunday I'll compare notes with you.

So according to my spreadsheet here, assuming you've got 5G of beer in there you'll get about 0.11G sucked back from the initial contraction due to cooling, and over time an additional 1.12G from the absorption of CO2.

 

[doug293cz]

So according to my spreadsheet here, assuming you've got 5G of beer in there you'll get about 0.11G sucked back from the initial contraction due to cooling, and over time an additional 1.12G from the absorption of CO2.

Unless I made a mistake, your formula for additional CO2 absorption by the beer is:

Head_Sp_Vol * (14.7 - 136.7 * (2 * Beer_Vol - Fermenter_Vol) / (14.7 * Beer_Vol - 10)) / 14.7​

I've got to admit I don't understand the model behind this formula. Can you explain the derivation.

Since I asked you to show me yours, I will show you mine.

The basic model is based on determining the equilibrium carbonation level for the beer temp at 1 atmosphere CO2 partial pressure, which is 0 PSI gauge pressure (assumes the headspace contains pure CO2, and there is no significant pressure head from the airlock.) The equation used comes from here (sec 2.1).

Volumes = (Press + 14.695) * (0.01821 + 0.090115 * exp( -(T - 32) / 43.11)) - 0.003342​

So the additional absorbed CO2 (in volumes) just the equilibrium volumes at cold crash temp minus the equilibrium volumes at the original temp. The physical volume of the CO2 at 1 atm pressure and 32°F is then just the beer volume times the delta carbonation level. I used 68°F for the starting temp, which gives an equilibrium carb level of 0.839 volumes. Final temp was 32°F, which gives an equilibrium carb level of 1.588 volumes. So, the additional absorption by 20 L of beer works out to:

Additional_Beer_Absorption = 20 L * (1.588 - 0.839) = 14.98 L​

Brew on

 

[Morrey]

@doug293cz ... what is your opinion here: With 5.5G of beer in a 7G SS fermenter, I will set my chiller to cool from 65F down to 35F which is going to happen rapidly with glycol, say a bit over an hour.

Last time I did this with a BO tube in starsan, the contraction caused a siphon drawing back 1/2G of star san thusly ruining the beer.

With the math you are able to apply in this situation, will almost 1 gallon of reserve CO2 suffice to displace the suck-back? In my application this weekend, I will see if I draw outside air in by the way the airlock on jar 2 behaves. If it sucks the airlock dry along with all the starsan sucked back into jar 1, I know my reserves are inadequate....right? If this is the case, I can add another jar in the daisy chain to add more reserve. Thinking ahead, Sunday will be the proof.

This pic is my setup, but in application I am using less starsan in jar #2 than is pictured, maybe half the amount shown.

 

[doug293cz]

@doug293cz ... what is your opinion here: With 5.5G of beer in a 7G SS fermenter, I will set my chiller to cool from 65F down to 35F which is going to happen rapidly with glycol, say a bit over an hour.

Last time I did this with a BO tube in starsan, the contraction caused a siphon drawing back 1/2G of star san thusly ruining the beer.

With the math you are able to apply in this situation, will almost 1 gallon of reserve CO2 suffice to displace the suck-back? In my application this weekend, I will see if I draw outside air in by the way the airlock on jar 2 behaves. If it sucks the airlock dry along with all the starsan sucked back into jar 1, I know my reserves are inadequate....right? If this is the case, I can add another jar in the daisy chain to add more reserve. Thinking ahead, Sunday will be the proof.

This pic is my setup, but in application I am using less starsan in jar #2 than is pictured, maybe half the amount shown.

With 1.5 gal (5.7 L) of headspace, I get your suck-back due to CO2 thermal expansion as 0.1 gal. You should see this as soon as the fermenter is down to crash temp (maybe even sooner due to the beer absorption.) However, as the CO2 level in the beer at crash temp comes to equilibrium with the CO2 in the headspace, you will get an additional suck-back of 3.4 gal (unless you start sucking back air, which will reduce the CO2 partial pressure.) To get this much total suck-back will probably take two weeks or more, but since absorption is fastest at the beginning of the process, it might only take a day or two to suck-back more than 1/2 gallon.

You should be using more sanitizer in your jar. Once the sanitizer in the last jar sucks back into the first jar, you start sucking air back as well as whatever CO2 is left in the jars. You want to start with the sanitizer in the first jar, and it should be filled to about 1/4" below the bottom of the nipple connected to the fermenter.

Then when you cold crash, you should keg the beer as soon as the sanitizer in the second jar is almost all sucked back to the first jar, if you want to avoid all air suck-back. Or, if you have the capability, you could blow CO2 into the fermenter until the sanitizer is all back in the second jar. Rinse and repeat as necessary to complete your desired cold crash time.

Brew on

 

[Morrey]

With 1.5 gal (5.7 L) of headspace, I get your suck-back due to CO2 thermal expansion as 0.1 gal. You should see this as soon as the fermenter is down to crash temp (maybe even sooner due to the beer absorption.) However, as the CO2 level in the beer at crash temp comes to equilibrium with the CO2 in the headspace, you will get an additional suck-back of 3.4 gal (unless you start sucking back air, which will reduce the CO2 partial pressure.) To get this much total suck-back will probably take two weeks or more, but since absorption is fastest at the beginning of the process, it might only take a day or two to suck-back more than 1/2 gallon.

You should be using more sanitizer in your jar. Once the sanitizer in the last jar sucks back into the first jar, you start sucking air back as well as whatever CO2 is left in the jars. You want to start with the sanitizer in the first jar, and it should be filled to about 1/4" below the bottom of the nipple connected to the fermenter.

Then when you cold crash, you should keg the beer as soon as the sanitizer in the second jar is almost all sucked back to the first jar, if you want to avoid all air suck-back. Or, if you have the capability, you could blow CO2 into the fermenter until the sanitizer is all back in the second jar. Rinse and repeat as necessary to complete your desired cold crash time.

Brew on

Understood. Once I get my 14G uni tank in place and operational, this suck back issue will be manageable since I can apply CO2 into the headspace easily.

Thanks for the tips on my current set-up!

 

[Climb]

@ btbnl – Nice work on the Excel file. I too do not understand your equations, so a more detailed explanation would be helpful in gaining a better understanding of the science and math behind this.

@ doug293cz – I really like you idea in post #5 to purge sanitized kegs with CO2. I have also seen this concept mentioned in other threads on HBT. Your post that you link to in post #5 of this thread is fantastic. Thanks for your contributions to this thread.

@ Jaybird – Nice build. Is the airlock on the second jar really needed? It doesn’t hurt, but I don’t think it is necessary. Maybe I am missing something.

I have been using a similar system to what Jaybird has created. I first time I saw this concept was in another thread here on HBT.

I do ~10G batches and use a Sanke keg as the fermentation vessel in a converted side-by-side refrigerator used for the fermentation chamber. From my experiences on several batches, I use about 5.85L (1.55G) of Star San and have noticed exactly what btbnl mentions in post #19 and #23. In that most of the suck back occurs after the minimum cold crash temperature has been reached. My minimum cold crash temperature is about 46F, a limitation of my fermentation chamber, and I keep it there for a minimum of 3 days, sometimes up to 5 days as I bottle on weekends. Using btbnl’s Excel file, for one of my batches, I get 2.11G of total suck back volume. My measurements are less than that calculated by btbnl’s Excel file, probably because I did not reach equilibrium.

My process …

1. I use a 5L Erlenmeyer flask as the first jar. I need the large flask for large yeast starters for 10G batches from one yeast packet, so this was not an extra buy for me. The Erlenmeyer flask is caped with an orange carboy cap wedged inside the neck of the flask. I was happy to find that this makes a nice air tight seal and has been adequate for the pressures in this application. This gives me the two ports that are needed for the first jar. For the second jar I use a 1G glass jug; I wish I had something larger like another 5L Erlenmeyer flask, but I don’t. I don’t use a top on the glass jug. I leave it open to the ambient air, as I don’t see the purpose for sealing this vessel. I run a hose between the Erlenmeyer flask and the glass jug. The hose runs through one of the ports on the orange carboy cap that is wedged inside the neck of the flask. As in Jaybird’s system, it is critical that this hose reaches the bottom of the Erlenmeyer flask.

2. At the beginning of fermentation, I start with the Erlenmeyer flask full of Star San. The CO2 from fermentation pushes the Star San into the glass jug. As the glass jug gets full of Star San, I pour some of the Star San into a storage container to make more room. Thus my point of having a larger second vessel would be helpful. I do this carefully, being sure not to breaking the inherent airlock. From doug293cz’s liked post in post #5, it looks like filling the Erlenmeyer flask with Star San isn’t needed.

3. By the second day of fermentation, all of the Star San is pushed out of the Erlenmeyer flask.

4. During cold crash, Star San is sucked from the glass jug into the Erlenmeyer flask. I continue to fill the glass jug with star San as needed in order to keep the airlock intact.

I hope others find this post helpful.

 

[Jaybird]

ROCKSTAR FEEDBACK AND INSIGHT YOU GUYS!


LOVE IT!

Are 4 dancing bananas 1 too many?

Cheers
Jay

 

[imasickboy]

Are 4 dancing bananas 1 too many?

Cheers
Jay

Another redhead will negate that banana overuse.

 

[Jaybird]

Another redhead will negate that banana overuse.

AMERICA! I am all about RED! Ok Ok Ok White and Blue too!

 

[TANSTAAFB]

I love it! I built something very similar years ago after reading about Burton unions. This is waaaay classier than my ghetto set up but mine still allowed me to fill a fermenter more so less headspace, capture clean, active yeast/ krausen, and avoid suck back. Great job Jaybird!

 

[Derp]

My hardware arrived yesterday and I have 10 gallons of bitter in a Speidel that I'd like to cold crash today. I'm not sure how to do it, since the beer has already fermented and isn't likely to be producing much CO2.

How should I approach it? Give each of the jars and the Speidel a blast of CO2 and then hook it up? How much StarSan solution should I put in the jar(s) and which jar(s) should I put it in?

Thanks for the cool new gear, Jaybird!

 

[Jaybird]

My hardware arrived yesterday and I have 10 gallons of bitter in a Speidel that I'd like to cold crash today. I'm not sure how to do it, since the beer has already fermented and isn't likely to be producing much CO2.

How should I approach it? Give each of the jars and the Speidel a blast of CO2 and then hook it up? How much StarSan solution should I put in the jar(s) and which jar(s) should I put it in?

Thanks for the cool new gear, Jaybird!

Yeah you can purge out all the O2 for sure. Hook it up and crash. In Jar 2 I would be using about 3/4 full of star san and you should be good. You using 1/2 gallon jars?

Cheers
Jay

 

[Derp]

You using 1/2 gallon jars?

Yep. I found a package of 6 at Walmart for $12.

Thanks for the info!

 

[doug293cz]

My hardware arrived yesterday and I have 10 gallons of bitter in a Speidel that I'd like to cold crash today. I'm not sure how to do it, since the beer has already fermented and isn't likely to be producing much CO2.

How should I approach it? Give each of the jars and the Speidel a blast of CO2 and then hook it up? How much StarSan solution should I put in the jar(s) and which jar(s) should I put it in?

Thanks for the cool new gear, Jaybird!

Unless the Speidel has been opened late in the fermentation, it's headspace should be pretty much pure CO2. I would proceed as follows:

• Fill the jar that will be connected to the fermenter to overflowing with StarSan, and then attach the two nipple lid.
• Connect the filled jar up to the second jar
• Attach a tube to your CO2 source, blow some CO2 thru it, and attach it to the free nipple on the first jar
• Blow all of the StarSan from the first jar to the second jar with CO2, then detach the tube from your CO2 source, and cover the end of the tube with your thumb
• Attach the end of the tube to the airlock on the Speidel
• Now dump about 15% of the StarSan out of the second jar, without pulling the dip tube out of the StarSan, and reattach the lid

The first jar and tube will be filled with CO2 with minimal O2 content. When you crash, you will suck back StarSan from the second jar to the first, but won't pull in any air unless you crash long enough to suck all off the StarSan back to the first jar.

Brew on

 

[TANSTAAFB]

That sounds like a massive PITA! Are y'all so worried about a little O2 exposure you are willing to jump through all these hoops? I would love to see an Xbeerment on this!

 

[Derp]

That sounds like a massive PITA! Are y'all so worried about a little O2 exposure you are willing to jump through all these hoops?

After experiencing severe oxidation issues despite attempts at avoiding it, yes.

 

[Jaybird]

That sounds like a massive PITA! Are y'all so worried about a little O2 exposure you are willing to jump through all these hoops? I would love to see an Xbeerment on this!

[ame]https://www.youtube.com/watch?v=SzadY-ZYubQ[/ame]

Now THIS is jumping through a hoop. LOL

Sorry couldn't resist.

It's actually not a PITA. Just adding a couple little jars to your blow off is all.

CHeers
Jay

 

[homebrwd]

New to the cold crash idea and plan on using it in the future, glad I found this but I do have a couple questions to make sure I understand. Does the first jar, connected directly to the fermenter, get filled almost completely with sanitized fluid to limit the amount of air in the jar? In the video there is only fluid placed in the second jar. In this scenario the first jar is 100% air and contains oxygen, which we do not want. As CO2 is pushed into the first jar during fermentation it will sink as it is denser than air and then be pushed right out into the second jar. During cold crashing the first gas to be pulled back in would be the air sitting atop the CO2 in the second jar, wouldn't it?

I would think that a better method would be to have two large jars, no liquid. Still using the provided lids on the first jar have the tube from fermenter go in and on the same connection have the dip tube effectively pushing CO2 into the bottom of the jar and pushing the air out of the outlet into the second jar, do the same on the second jar with the dip tube being on the inlet. Again as the first jar fills with CO2 it will push air through the second jar until it too begins to fill with CO2 while pushing air through the air lock on the lid. As long as the dip tube in the second jar is short enough to not pull in the water from the s lock off the bottom of the jar during crashing you should reclaim mostly CO2. Am I overthinking this?