Preventing suck back while cold crashing

[Jtvann]

Just starting now to cold crash my latest IPA. Fill balloon with CO2 from keezer. Attach to blow off.

 

[JimRausch]

I've never had any suckback problems, although I have read many posts about it. But if I ever do, I'm using your remedy. Genius!

 

[doogster]

Cool idea!

JTVann - how do you like the brew bucket and heating/cooling components? I'm considering a purchase.

 

[brewcat]

on a brew bucket... Otherwise just install a solid bung.

 

[Jayjay1976]

Just starting now to cold crash my latest IPA. Fill balloon with CO2 from keezer. Attach to blow off.

What about those of us who don't have a CO2 bottle handy?

 

[Jtvann]

Without a CO2 bottle ... eh, you’re screwed. Maybe blow the balloon up yourself. Air is over 78% CO2, after you exhale, some O2 is removed and more CO2 produced. I’m just making crap up though as I drink ... probably not good advice, but it sounds cool.

As far as a solid bung ... I used to do that. Even used to do it with a glass carboy. Every time I removed the bung to rack, loud sucking of air rushing in. No way to avoid it. Same volume of air he’s pulled in all at once as it would have slowly. Less total time for contact, but air still get in.

As far as my impressions of the SS Brewbucket and cooling ... I absolutely love it. I bought two. I’ll never look back. Can do pressurized transfers, harvest yeast, clean it super easy, will last for years if not a lifetime, temp control is a breeze. I live in Death Valley. Last month it was in the mid 70s during the day and 50s at night. Switches between heating and cooling to keep temps constant. You can go as simple as a cooler of ice, a keg in a fermentation chamber, or a glycol chiller. I can’t say enough good things about my brew bucket. So much happier I bought it vs the chronical. I can cold crash with a cooler of ice, or even fit 2 of them stacked on top of each other in my stand up freezer/fermentation chamber.

 

[Jtvann]

Roughly 2 hours later, the balloon is a little smaller and it’s down 30 degrees.

 

[day_trippr]

That's one sad balloon. I predict total deflation before morning.
Cold beer = gas sponge

Cheers!

 

[Jtvann]

I’ll take that bet. No cheating on my part. Will follow up in the am.

She might be saggy, but she’ll still be there as an air lock and have some CO2 left.

 

[brandonlovesbeer]

When I cold crash I just seal off the top of the carboy.

 

[Sadu]

Not an option for everyone, but if you ferment under pressure then suckback is a total non-issue. The pressure just drops a bit when you cold-crash.
Just one of many reasons why pressure-fermenting is awesome.

 

[brandonlovesbeer]

To seal the top I just rubber band some folded plastic wrap over the hole.

If you are using a bucket. I assume just modify it by:
Put a 3-piece airlock in the hole. Take out all the pieces. Then just put the plastic wrap and rubber band on the top of the air lock.

Same result.

 

[Jtk78]

This thread shows how I prevent it with a Fermonster. Also a fix for a closed transfer to keg.

https://www.homebrewtalk.com/forum/threads/fermonster-back-suck-back-closed-transfer-fix.646893/

 

[Jtvann]

Near total deflation. But it does still have some positive pressure from the outside.

Crimped off the tube and added a new balloon

 

[Jtvann]

One thing these pictures do clearly show is the potential volume of air that is pulled into and possibly diffused into the beer

 

[JohnSand]

It looks like a great idea. Do you have any concern about chemicals from the balloon? I guess nothing dangerous would be in a toy that children inflate by mouth. I admit it's been a long time since I blew up a balloon, is there some powder to prevent sticking, or anything that might affect the flavor and color of the beer?

 

[TheHopfather]

What about those of us who don't have a CO2 bottle handy?

Just add the empty balloon to the carboy while the beer is still fermenting. The fermentation will fill it with pure CO2, I do this all the time.

 

[PMcGuen]

How long did you crash and how many balloons did you use? Knew suck back was a thing, but didn’t realize it was this big a deal when you are trying to avoid oxygen

 

[Jtvann]

One balloon, filled it twice. Might have got by with once. It’s only a problem while the temperature is actually changing. Once temp stabilizes, it’s safe

 

[PMcGuen]

Took three balloons of CO2 to get me from 68f to 39f. Crazy how much air you are getting in your beer from a simple cold crash! Thanks for posting this!

 

[Kealia]

As far as my impressions of the SS Brewbucket and cooling ... I absolutely love it. I bought two. I’ll never look back. Can do pressurized transfers, harvest yeast, clean it super easy...

How are you harvesting yeast? I have the 7G with the Thermowell and the same spigot you have....?

 

[Jtvann]

After kegging the beer, I put in a gallon of sterilized water from 4 mason jars. Swirl everything up and then let it rest for about 10-15 mins. Fill mason jars back up that the sterilized water came from.

I’ve since moved on to just over building my starters by 1 liter and saving it for my next starter.

Overall I was happy with the yeast wash/harvest, but I think it’s easier to just over build.

 

[Kealia]

Ah, gotcha. I thought you were somehow dumping the yeast and removing it from the wort/beer.