Question on Cold Crashing

[muse435]

When you cold crash how do you prevent liquid from the air lock from being sucked back int to the carboy? Are you worried about introducing O2 int the head space when the air condenses as it cools?

Obviously people do this all the time with out an issue i was just curious tho since there is enough space in my keezer to try cold crashing on this batch.

 

[poptarts]

if your airlock is at a correct level it shouldnt have enough liquid to suck back. alternatively you can just toss foil on top till its cool then place the airlock back in place. Just dont do it with a blow off hose or you will get some massive suck back.

 

[day_trippr]

If you use an S-lock you won't have any issues with suck-back, unlike with three-piece locks...

Cheers!

 

[muse435]

Any worries about O2 entering into the carboy?

 

[day_trippr]

That discussion has its own lengthy thread somewhere here, but I can't seem to find it right now.

I don't think there was a conclusion, but your basic premise is correct, and is mediated primarily by head space volume: the greater the head space the more vacuum will be pulled when the temperature drops, hence more air will enter the fermenter. And cold beer accepts gases more readily than warm.

Unless you have virtually zero head space in the fermenter or you provide something other than air to equalize the head space pressure through the cold-crash, air is going to get in, and presumably some of it is going to dissolve in the beer.

To be honest, after years of cold-crashing batches I've never had a reason to believe there was a problem with oxygenation. But I went ahead and implemented a system that eliminates air ingress during the crash, just because I could and I had most of what was needed already in place...

Cheers!

 

[muse435]

I very much like the idea of what you did there. I plan on cold crashing in my keezer so I too have access to co2 hookups. How did you connect the ball valve to the carboy cap?

 

[MikeInMKE]

I've seen a video where a clever dude attaches a mylar balloon to his airlock to capture CO2. I've been intending on trying this technique so the only thing getting sucked back through the airlock during cold crashing is previously generated CO2.

 

[muse435]

I tried something like that a few years back when I attempted cold crashing. I was using a bung not a cap and it ended up pushing the bung and air lock out. I heard it happened so I just ended up racking to the keg and skipped the cold crashing.

 

[muse435]

After looking at the above picture I think I am going to try something very similar. After I'm done cold crashing I am going to attempt to push the beer into the keg then instead of syphoning it.

 

[day_trippr]

Google is awesome and all seeing. I searched the image above and it found the thread I had referenced earlier.

Now if I could find my post that detailed the pieces needed

Basically it's a Firestone gas post with its 9/16-18 thread, an adapter that threads into that with its own captive o-ring (mimicking a keg riser/o-ring/dip-tube flange) and in turn provides a 1/4" FFL thread, into which a 1/4" MFL-1/4" barb is threaded with a nylon flare gasket in between.

All the parts are available at chicompany.net and other places...

Cheers!

[edit] I added a close-up pic. Note the tape between the clamps and balloons. Also I stuffed a short piece of 1/4" copper tubing inside the cap so the clamp around the balloon wouldn't simply collapse the carboy cap nipple.

The balloons are essentially fuses in case the regulator loses its mind. Normally the pressure is truly minimal - I set the pressure just to get the needle off the stop - but I figured it would be prudent to have something blow up before the carboy does, just in case something went totally wrong. So far so good

 

[bobeer]

Honestly, I don't use anything to prevent oxygen from getting on to my beer while cold crashing. I've never had any issues with oxidation. I just use some tinfoil to prevent anything from getting in the fermentor. I figure oxygen will touch the beer during the kegging process anyway so I don't bother with trying to keep it away during cold crashing. My beer tastes great so I stick with what works for me

 

[day_trippr]

[...]I figure oxygen will touch the beer during the kegging process anyway so I don't bother with trying to keep it away during cold crashing.

That's not inevitable - lots of folks use CO2 to push from one purged vessel through purged tubing to a purged receiving vessel. No chance for O2 to join the party.

My beer tastes great so I stick with what works for me

I totally concur with that philosophy
A lot of what I get into is just to satisfy my inner nerd...

Cheers!

 

[muse435]

Honestly, I don't use anything to prevent oxygen from getting on to my beer while cold crashing. I've never had any issues with oxidation. I just use some tinfoil to prevent anything from getting in the fermentor. I figure oxygen will touch the beer during the kegging process anyway so I don't bother with trying to keep it away during cold crashing. My beer tastes great so I stick with what works for me

I completely agree with what said here and every batch I have done to date I have siphoned from the carboy. Half the time I purged the jaeger with co2 half the time I forget. But as mention there is a lot of fun with the nerd side of brewing. Plus after looking through my brewing/legging supplies for about $3 I can rig up something similar to prevent O2 from coming into contact.

If u wanted simple I would just buy some craft beer 😎

 

[Harry482]

Honestly, I don't use anything to prevent oxygen from getting on to my beer while cold crashing. I've never had any issues with oxidation. I just use some tinfoil to prevent anything from getting in the fermentor. I figure oxygen will touch the beer during the kegging process anyway so I don't bother with trying to keep it away during cold crashing. My beer tastes great so I stick with what works for me

What he said!

 

[muse435]

Honestly, I don't use anything to prevent oxygen from getting on to my beer while cold crashing. I've never had any issues with oxidation. I just use some tinfoil to prevent anything from getting in the fermentor. I figure oxygen will touch the beer during the kegging process anyway so I don't bother with trying to keep it away during cold crashing. My beer tastes great so I stick with what works for me

I completely agree with what said here and every batch I have done to date I have siphoned from the carboy. Half the time I purged the jaeger with co2 half the time I forget. But as mention there is a lot of fun with the nerd side of brewing. Plus after looking through my brewing/legging supplies for about $3 I can rig up something similar to prevent O2 from coming into contact.

If u wanted simple I would just buy some craft beer 😎