Cold Crash and Dry Hop Question

[ike8228]

I’m still newish here, mostly posted in mead. Been brewing for a few years. Anyway I’ve been doing a ton of reading on here and haven’t quite found an answer that suits my question completely. I have an idea of what to do but want to consult with more experience brewers.

I’m doing an IPA 5 gallons in a glass Carboy in a temp controlled fridge primary only. I need to dry hop soon. I am fully aware of oxygen prevention and do my best, as we all do, but my question relates to cold crashing when it’s done. I need to cold crash after 4-5 days of dry hop for them to fall out of suspension as much as possible. But I also read that cold crashing IPAs can also make other ‘stuff’ fall out that you may not want to? Gelatin/clearing I already assumed would make a lot of the goodness of IPAs fallout so I want to do a cold crash. Will this still result in a good hoppy beer? I know some of the best ways is to just let it sit and fall out, but I can’t do that if I’m dry hopping, from what I’ve read? More or less my question I couldn’t pin down reading and searching was, will cold crashing settle the dry hops without settling out some of the hazy/hoppy flavors?

Second part to the question is, I’ve been reading everyone’s ideas and thoughts of suck back during cold crashing. I plan to come up with a system for that in the future. But since I’m there now, if I use a glass carboy and a solid (no hole stopper) will it still suck air in? Or will it just build up pressure in the carboy? Which if it does build pressure I’m confident saying it will not break right?

Thanks, sorry if this has been address and I just didn’t find it.

 

[Tallgrass]

For a long time I didn't cold crash. Most of the time hop materials would fall after a few days. If not, a quick shake would get it moving. On the more stubborn batches I would use the large hop sack I used for the boil to filter it out when I racked.

I wouldn't put a solid stopper in a glass carboy to cold crash. I've had my plastic fermonsters collapse quite a bit from the vacuum created. When you pull that stopper out to rack it's just going to suck back air anyway.

I have been trying to find a solution myself to sucking O2 back when cold crashing and have seen some pictures on this forum of inflated balloons on carboys. You might search the forum for various solutions.

My latest attempt is filling a corny with starsan and letting fermentation gases force that solution out of the carboy into a bucket. I have done this a few times and it works fine. The starsan bucket becomes a giant airlock. The question is whether the plastic fermenter will collapse when the beer gets cold or will it pull the starsan back into the corny. I'll know this weekend when I try.

 

[DVCNick]

The easiest way is to just get a pressurizable fermenter like a Fermentasaurus or similar. Once fermentation is trailing off you can put on a spunding valve and let the pressure build up some so there are no issues cold crashing. I've found that 10psi is plenty to maintain positive pressure through a cold crash. (And if you don't put the spunding valve on in time, you can top it up with bottle gas, easily). I know it is a little bit of extra cost, but it works very nicely and, in my opinion, is probably worth it to not have to play around with jerry rigged setups using vessels that weren't meant to hold pressure in the first place.... ymmv

 

[bailey mountain brewer]

cold crashing does not build pressure. the opposite, it creates vacuum. i would not use a solid stopper. for a carboy the easiest is the balloon method. as for your flavor if you dry hop for 3 or 4 days at 70* then cool it down you shouldnt lose anything as far as flavor or aroma. also depends on the type of ipa you are doing. dank west coast or neipa, have some different processes and dry hop rates.

 

[mattdee1]

I'll go rogue and put in a vote for skipping cold crashing altogether. Doing it in such a way that it does not compromise anything else in the process (i.e., oxygen exposure) is - as can be plainly seen by looking around this forum - a pain in the ass without a fermentor capable of holding pressure.

I get that with highly-hopped beers there is a need to address the issue of hop particles jamming up the works during transfer. If this is the primary goal of the cold crashing, then I sympathize, but there are other ways of addressing that, depending on what kind of fermentor you're using.

If clear beer is the primary goal of the cold crashing, doing that step amounts to unnecessary risk and complexity for no net benefit. After all, the beer will clear on its own in a refrigerated serving vessel. It might take a bit longer, sure. But you'll have eliminated a vector for oxygen intrusion, which is far more important than expedited clarity, IMO, especially for hoppy beers.

 

[jtrux]

For cold crash, this last batch I used an S type airlock with everclear in it. To the end I attached a vinyl tube. The other side of the tube had a 10 gallon trash bag taped tightly. This was added towards the end of fermentation. To make sure I captured enough co2, I added 5 oz table sugar then proceeded to do my diacetyl rest. During cold crash, I just sucked back the co2 produced during the end of fermentation. Seemed to work well

 

[ike8228]

So to address a few topics mentioned here.

I did see the ballon tactics and even a catheter bladder bag to prevent suck back or rather suck back co2 instead.

I meant negative pressure as in vacuum you are correct.

With waiting for the hops to settle, I thought you need to get the beer off the dry hops after a few days so they don’t start to oxidize or turn off flavors? Are you supposed to bottle or at least rack after the 3-5 days of dry hop. That contradicts waiting, or will it settle enough by then?

 

[PhillyBrewDoug]

So to address a few topics mentioned here.

I did see the ballon tactics and even a catheter bladder bag to prevent suck back or rather suck back co2 instead.

I meant negative pressure as in vacuum you are correct.

With waiting for the hops to settle, I thought you need to get the beer off the dry hops after a few days so they don’t start to oxidize or turn off flavors? Are you supposed to bottle or at least rack after the 3-5 days of dry hop. That contradicts waiting, or will it settle enough by then?

What kind of hops are you using (pellet, cone)? If you're using whole hops, they float a lot and trying to wait for them to settle out will be a losing battle. You could always put the hops in a hopsock and weigh it down with a sanitized stainless steel part. I often see people say they use washers. That will keep the hops submerged and also contained so you can rack whenever you like.

 

[bailey mountain brewer]

yeah, 3 to 5 days. then get it off the dry hops. i do agree that avoiding oxygen is more important then having clear beer as mentioned above, having a vessel that gives you the ability to do it properly is key. i know in the past i have had hop material clog things up when i wasnt able to cold crash which was frustrating but i worked through it. i know guys have put things like muslin bags on the bottom of their racking canes to act as a filter. its a tough thing as there is no one way to do it and youll have to find what works for you. doing what HarlemBrewDoug has mentioned is a great technique.

 

[ike8228]

Thanks guys I think this answered the specifics to my question. Another thread popped up today or was revived with a similar issue and it gave me a little more light as well.

Having thought about it and seeing a couple of ideas involving balloons I think I have a great idea that combines those ideas with a twist. I will work on it, experiment and post my contraption. Probably will post it in the DIY too. Maybe someone’s done it, maybe not. I try not to Mickey Mouse things, or if I do, make it as legit (looking?) as possible.

In terms of the hop bag/sock, I do have one, it’s some plastic material so it should be reusable. I’ll try that next time.

I’m wondering if I can come come up with a way to rig it in the fermenter during initial transfer, then when it’s time to dry hop, pull a string thru the bung or airlock that releases/drops it into the beer, therefore avoiding adding oxygen when removing the bung to put the bag/dry hops in.

My list of DIY experiments is growing faster than I can perform them.

 

[Tallgrass]

I saw someone use a magnet to hold the hop bag until the right time. Don't know if that would work through the glass and dropping that might not be the best practice.
Good luck. It seems many people here enjoy the DIY aspect. After all we are DIYing our own beer.. My used window A/C chiller, plastic fermenters and tackle box temp controler isn't going to be featured in any magazine but it makes a lot of good beer.

 

[PhillyBrewDoug]

If you really want to avoid adding O2 into the fermenter look into adding it during fermentation (bio-transformation I think) or dry-hopping in the serving keg which you can purge with co2 before transferring. That’s assuming you keg. I’ve left hops in my keg for a couple of weeks and the beer didn’t taste grassy or off.

 

[ike8228]

I saw someone use a magnet to hold the hop bag until the right time. Don't know if that would work through the glass and dropping that might not be the best practice.
Good luck. It seems many people here enjoy the DIY aspect. After all we are DIYing our own beer.. My used window A/C chiller, plastic fermenters and tackle box temp controler isn't going to be featured in any magazine but it makes a lot of good beer.

That’s not entirely a bad idea actually. It would need to be something coated in a food grade not contaminating thing. If you use stainless hardware to weigh it down like some have suggested, stainless is not magnetic. It would have to have iron.

I have one of those magnetic scrubbers for the hard to get to spots in the carboy neck. But it’s a fairly weak magnet. I don’t know if it’s food grade. Something to think about. Thanks for the idea.

 

[balrog]

Magnets scavenged from old hard drives are hella-strong.
Put them in a food saver bag vac sealed, or just a ziploc, either which can be sanitized and used on the inside with more HD magnets on the outside. Even a stir bar with a hard drive magnet holds easily through glass.