It’s my first cold crash, I have some questions

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Chaos Brews

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Hi all, so I’ve been reading multiple posts and watching YouTube vids around cold crashing and all have either scared me from doing it or made it sound simple. I want to give it a go to try get some clarity in my USA IPA brew that is on now.

Here is some info on my brew so you know where I’m at:

- fermentation has finished by day 11, gravity is consistent at 1.012 (abv avg. 5.91%)

- I just dried hopped today (Day 11 - Used a food grade magnet holding dey hop bag in suspension so i didn’t have to open the fermenter) as I intend on bottling in the next 4 days (about 2 weeks in the fermenter)

- Fermenting at 21c in a fridge

- I will rack the beer to a second fermenter to get a good swirl of the priming sugar and then bottle from the second fermenter straight away and then put it back in the fridge and bring temp back up to 21c for 2 more weeks of conditioning

- I have a temp gauge in a DIY thermowell in the wort

As titled, I have many questions:

1. I plan to cold crash from today/tomorrow? So about 3/4 day cold crashing. Im aiming to get to about 1-2c. I’ve read this is ok timing for an IPA. Any probs with this?

2. I just dropped the dry hopped, should I wait a few days before starting the cold crash or is it fine just to go ahead and do it today/tomorrow? Will it effect the dry hopping much?

3. What’s scared me is hearing about. “suck back” my air lock has vodka in it. will cold crashing suck that back into the fermenter and then leave nothing there letting more air in?

4. is there anything I am missing or need to consider?

big thanks for any advice :)


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@Chaos Brews
Firstly many ways to skin a cat. But you want to cold crash. You should be concerned about suck back, drive without a seatbelt be scared.

I tend to dry hop cooler around 14 celsius for my IPA, but many warmer and some do it at colder temps. The hops are in anyway so that's a done deal, duration I'm DHopping for about 4 days. But of course you could drop the temp now for a few days and then cold crash at the end of dry hop duration and also pull the hops back up on your magnet.

However / But

As the beer cools the pressure will drop in the fermenter and pressure will want to equalise between fermenter and the rest of planet.
Your air lock is unlikely to have the vodka sucked into it during this process, after all when the beer was fermenting the vodka didn't get forced out! and suck back is just the process in reverse.

The issue that is essential is to keep oxygen away from the beer at all costs, so any suck through the airlock lets air in and the issues will commence, hence pressure capable fermenters with positive pressure useful as cold crashing they don't do that. That nugget doesn't help you though.

This thread does describe a method that will help
You also mention transfer to another vessel to prime good swirl then bottle.
Again this just increases your oxygen beer exposure. I would just cold crash ( with suck back prevn) if you wanted you could inject some finings thru airlock hole removed and replaced briefly when beer cold and give a shake / swirl with the suckback mitigation in place.
Then when ready to bottle calculate your priming sugar, eg 3g per bottle ( use priming calculator ) then dissolve that in ( say you have 25 bottles ) 125ml of boiling water.
Use a syringe and put 5 ml per bottle, that way each bottle has correct dose and it's dissolved ready to go. Make sure you have a system say clean bottles on bench, prime with sugar put it on floor. That way you won't miss one or double fill one.

Drink your vodka ( not the stuff in the airlock) and just use some starsan or sod met solution in your airlock next time. You probably sanitise your airlock in starsan anyway not vodka i hope. During ferment the alcohol in vodka will get driven off by the co2 going thru the lock so in the end you probably have just water which you certainly wouldn't want to suck back into fermenter. After all if you leave the vodka bottle unscrewed there's less there after a few months.
Ich schliesse zum Druckausgleich beim CC einen mit CO 2 gefüllten Ballon an.

Viele Grüsse aus Deutschland/Germany


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Hi there,
tiny cheap but worked best for two of my brewbuckets.
a non return valve adjustable knob.
the larger blow off tube i just used strong tape (it’s hasn’t failed yet lol)
getting a bung, hose etc shouldn’t be hard, i hope.
bri 🫡


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