Temp reduction suckback - Let's brainstorm

[Bobby_M]

I wouldn't worry about air getting in prior to fermentation. It's the cold crashing just prior to lagering or packaging where I don't particularly want ANY O2 getting in there.

I agree with dstar26 though... a CO2 blanket is an imaginary security blanket. CO2 and O2 don't repel each other, they play nice just like what happens in the atmosphere.

 

[johnnybrew]

I guess if you are concerned about O2 exposure you could modify the rig below to include a CO2 intake/supply. I would think that if you filled a balloon with CO2 from your keg setup and then attached the balloon to the other side of the filter, you would only take in filtered CO2 into your carboy as the temperature and pressure changed. To ensure the balloon didn't leak, a simple zip-tie would do the trick. Thoughts/feedback?

 

[jamest22]

Why not take a CO2 tank with the regulator set to 1psi and set it up to feed into the carboy through a hood/stopper. That way as the pressure drops in the carboy while crashing, CO2 will enter to keep it filled. (maybe someone has already suggested this, I haven't read the whole thread).

 

[Bobby_M]

I agree that a balloon filled with CO2 is a fine solution. I'd probably want to use something like a mylar O2 barrier bag so that the CO2 wasn't really under pressure.

 

[johnnybrew]

...I'd probably want to use something like a mylar O2 barrier bag so that the CO2 wasn't really under pressure.

Good idea. Might try this out on my next cold crash.

In the past, I used a balloon alone (as someone on this thread suggested). It worked out ok, but the amount that it was drawn back into the carboy was cause for concern. It was under a lot of pressure and could have easily gotten pulled into the vessel. I should have snapped a photo because the inflated balloon inside the carboy was interesting to see.

 

[Bobby_M]

5 gallon mylar water bag. I'd just chuck a drilled stopper into the opening. I bet you could run a hose from the side port of a carboy cap into here leaving the center one into a blowoff container and it would probably inflate just fine.

 

[seyahmit]

I sanitize some saran wrap and rubber band it tight around the neck of the carboy.

 

[SirBC]

I use the CO2 adapter at 1.5 PSI while crashing and then will dump trub and push to keg.

 

[bigbeergeek]

Clearly there's a dozen ways people deal with this "problem." I just use a long 1/2" blowoff tube. I attach the tube a couple of days before I crash, residual fermentation displaces the O2 from the line, and the suck-back is O2-free and no liquid gets into the carboy. It might very well be overkill, but at least it is straightforward, simple, and I didn't have to buy/rig-up anything new to do it. It's all equip. that every one of us already owns.

 

[johnnybrew]

Here's the latest version of the idea. Seems to be holding pressure ok. The parts are simple: a balloon filled with CO2 attached to a millipore filter. I used tape in places to snug up the seal.

 

[bigljd]

This may have suggested already (also didn't read the whole thread), but I crash cool every batch before kegging and just throw one of those $2 S shaped airlocks on and there's no suckback issue with those. No need to overcomplicate things.
Edit: I re-read some of the recent posts and I guess the concern is no longer suckback, but oxygen getting back in. Guess the s airlock won't help with that.

 

[johnnybrew]

Edit: I re-read some of the recent posts and I guess the concern is no longer suckback, but oxygen getting back in. Guess the s airlock won't help with that.

Yeah, more of a concern with O2 than with bugs. But, I prefer to ensure no goobers are getting in there and use the filter for good measure.

 

[dermotstratton]

I'm getting ready to cold crash my conical and found this thread very useful. I understand the concern about avoiding oxygen and bugs when cold crashing. The thing I'm still confused about, though, is how to avoid oxygen and bugs from entering the brew when you are racking or taking samples from the vessel?

Right now, when I take a sample, I pick my hose out of my StarSan bucket and then use sample valve on conical to take the sample. When I do this, I realize I am pulling in oxygen and potential bugs. I have since thought that I could dip a piece of paper towel in StarSan solution and rubber band it to the end of the hose to act as a kind of filter for macro-sized crap from getting into the conical during sampling and/or racking keg. This will not prevent oxygen from getting in, though.

So, I guess my question is what good is it to come up with this complex solution to cold crashing if you've not already found a better way to sample and/or rack from your vessel? Is there an easier solution to sampling/racking that I am missing?

 

[johnnybrew]

Whenever I take the airlock off and grab a sample, I always purge the carboy with CO2 after I put the airlock back on. Take a look at the previous pic that shows the type of carboy cap I use. All I do is take the little white plastic cap off of the sample line on the carboy cap, put the filter on, and then run CO2 through the filter into the carboy. It makes the airlock bubble like crazy. So, I usually need to add a little more cheapo vodka to the airlock. I do this for about 30+ secs.

Also, every time I rack to the keg I purge my keg with CO2 BEFORE and AFTER racking.

I try and minimize O2 exposure to a great degree and have seen an improvement in my beer. Mostly, I see the improvement for kegs that sit for months; they stay fresher longer and I rarely see any negative effects from O2 / staling.

Good luck.

 

[dermotstratton]

That makes sense, I guess I could come up with an equivalent solution on my conical. I guess all I really need to do is stick a hose down into the head space, blast some CO2 in there for about 30 seconds to displace the O2 I just sucked in and then re-attach the blowoff tube. right?

For racking to a keg, I can just splurge and buy this CO2 adapter. It would be nice if it had 4 outlets instead of 3, though. Then you could have 1 outlet hooked up to conical, 1 outlet dedicated to thermowell, 1 outlet dedicated to airlock and 1 outlet dedicated to CO2 purge. I think that would work, right?

I would be very interested to do a side by side comparison of a beer done with and without this hypersensitivity to O2 and see if you can detect a difference after 6 months of aging.

 

[BioHopology]

Slap a "jimmy" on your hose before putting it in the "box".

Best homebrew line ever!