Experienced homebrewer cold crashing for the first time

[pursuit0fhoppiness]

Hi all. I’ve been brewing for 4.5 years now, but have never cold crashed a beer. I bottle condition, and a few weeks in the fermenter and occasionally clarity ferm have been all I need. EXCEPT with dry hopped beers, and I’m planning to do a hazy IPA soon so I want to finally try. I have a mini fridge that I can clear out and fit a fermenter in, I just have a couple questions about the process:

1. I don’t wish to use a CO2 balloon or similar device, and I don’t have any pressure fermentation equipment. Am I able to just hard bung the fermenter, rather than keep the airlock on to avoid starsan suck back? Or will hard bunging create a vacuum as the air in the fermenter cools? Not sure what my best option is for bunging/airlocking.
2. Can I just take my fermenter from ~18C right into the 5C fridge? I don’t have an inkbird for the mini fridge so not really able to slowly crash it.
3. How many days is typical for cold crashing a heavily dry hopped IPA?

Thanks for any help, I really appreciate it!

 

[marc1]

Hi all. I’ve been brewing for 4.5 years now, but have never cold crashed a beer. I bottle condition, and a few weeks in the fermenter and occasionally clarity ferm have been all I need. EXCEPT with dry hopped beers, and I’m planning to do a hazy IPA soon so I want to finally try. I have a mini fridge that I can clear out and fit a fermenter in, I just have a couple questions about the process:

1. I don’t wish to use a CO2 balloon or similar device, and I don’t have any pressure fermentation equipment. Am I able to just hard bung the fermenter, rather than keep the airlock on to avoid starsan suck back? Or will hard bunging create a vacuum as the air in the fermenter cools? Not sure what my best option is for bunging/airlocking.
2. Can I just take my fermenter from ~18C right into the 5C fridge? I don’t have an inkbird for the mini fridge so not really able to slowly crash it.
3. How many days is typical for cold crashing a heavily dry hopped IPA?

Thanks for any help, I really appreciate it!

1 - No. As you surmise that would reduce pressure in the fermenter as the CO2 in the headspace cools. If you are under pressure to begin with, you can keep it sealed.
2 - yes.
3 - it can take a day or 2 to get your beer down to temp, depending on your volumes and fridge. I let it go a few total, but don't have a hard and fast rule.

 

[Nuke83]

Just curious, why no interest in capturing CO2 in a mylar balloon, then using it during cold crash?

Space limitation?

That's what I do and it works great. Very simple and effective. I hit Dollar Tree and get an uninflated mylar balloon for a buck, tape it to some tubing that I can then put over my airlock and all the suck back is CO2 (I do purge the tube of O2 beforehand, so only CO2 in balloon and tube).

 

[Velnerj]

Not sure why you'd start cold crashing with a style like a *hazy* IPA. Considering that cold crashing is typically done for clarity and clarity doesn't seem to be important with that style...

On the other hand, there's also the issue of cold dry hopping... Might be something to look into.

 

[micraftbeer]

What type of fermentor do you have? It can affect cold crash options.

And to the previous question, what is your goal with cold crashing? I cold crash and have my reasons, but I don't want to assume yours are the same.

 

[pursuit0fhoppiness]

Thanks for the input guys. My reason for cold crashing a hazy IPA is to drop out all the dry hops so I don't end up with hop matter in my bottles. I typically dry hop in mesh screen "hop spiders", yet still get hop matter in each bottle so I need to be very careful when pouring. Would be nice to not have that happen and not have to worry about it. Also micraftbeer I use a SS Brewbucket.

My main concern was what to bung/airlock it with. Would the vacuum created from hard bunging be enough to damage a stainless fermenter or cause other issues?

 

[micraftbeer]

I don't think you'll collapse your SS BrewBucket. However, the greater the vacuum, the greater the risk you'll suck in air through some seal that's not designed to handle it.

For dropping hop debris, I've had luck even with a slight temperature drop, like from 75f down to 60f, and his drop pretty quickly.

Of course once you go to bottle, you might need to deal with this vacuum to get beer to flow, but minimize the time exposed to oxygen.

I would bung it, drop temperature to like 60f for 12-24 hours, and you should see reduction in hop particles.

 

[Kickass]

I wouldn’t cold crash a hazy unless you can prevent O2 suck back. You’ll be well on your way to early oxidation, otherwise. Additionally hard bunging, though may or may not damage equipment, will equalize drawing in O2 the second you pull the bung.

 

[Rish]

I wouldn’t cold crash a hazy unless you can prevent O2 suck back. You’ll be well on your way to early oxidation, otherwise. Additionally hard bunging, though may or may not damage equipment, will equalize drawing in O2 the second you pull the bung.

If you allow the fermenter temperature to come back up to where it was before crashing, won't that equalize the pressure and prevent sucking air in?

 

[pursuit0fhoppiness]

Yeah I'm not concerned with opening it at bottling time as since I bottle condition that oxygen gets scrubbed quickly anyway. I just don't want to let much in at end of fermentation/during cold crashing where it'd be in contact with the beer for days.

Unfortunately I can't drop to 60F only, as I don't have an inkbird for my mini fridge. It'll be all or nothing!

I'm thinking if I just cold crash for a couple days, I could quickly pull out the hard bung in the middle to release any negative pressure, and some oxygen will get in but hopefully with the bottling a day or so later and the re-fermentation starting within another day or two, the oxygen would still be scrubbed before the beer actually oxidizes.

 

[pursuit0fhoppiness]

I could also hard bung it towards the very end of fermentation just to build up a small amount of pressure, so that pressure will subside before it forms a negative pressure. I think?

 

[micraftbeer]

You could try to bung to build positive pressure, but the downside is if you're too successful, you might permanently bend something or cause something to blow off and go flying across the room when it lets go.

If you can only do full fridge temp, I'd still just aim for a short time (12 hours), see if you notice a difference. I'd avoid pulling the bung and letting the oxygen in and letting it sit for another day cold. I'm pretty sure you won't be happy with those results in your NEIPA.

 

[micraftbeer]

Plus, if you've got the financial backing to risk blowing out your SS BrewBucket, maybe you should just do $100 and but a FermZilla All Rounder with pressure kit from More beer for $100 and then be able to ferment under pressure, cold crash in a closed vessel, and do closed transfers when you're done with all of that.

Or buy a keg and use that (purged first) to cold crash in.

 

[TkmLinus]

Thanks for the input guys. My reason for cold crashing a hazy IPA is to drop out all the dry hops so I don't end up with hop matter in my bottles. I typically dry hop in mesh screen "hop spiders", yet still get hop matter in each bottle so I need to be very careful when pouring. Would be nice to not have that happen and not have to worry about it. Also micraftbeer I use a SS Brewbucket.

My main concern was what to bung/airlock it with. Would the vacuum created from hard bunging be enough to damage a stainless fermenter or cause other issues?

Have you tried a 5 gallon paint strainer bag in your bottling bucket to catch the hop residue? I put a 5 gallon paint strainer into my kegs and rack into the bag, when the keg is full I pull the bag and get all the stray hop matter with it.

 

[Brewer Mike]

I haven't done any cold crashing either. Does it affect the amount of priming sugar used, or is that still based on the temp during the conditioning phase?

 

[Velnerj]

I haven't done any cold crashing either. Does it affect the amount of priming sugar used, or is that still based on the temp during the conditioning phase?

It shouldn't affect the amount of priming sugar because you should be calculating the highest temp reached during fermentation. CO2 goes out of solution as temps rise.
However I noticed that when I Bottled after cold crashing it took longer to carbonate due to the low temps (I bottled when the beer was cold). But I also noticed better clarity and less sediment in the bottles.