• Please visit and share your knowledge at our sister communities:
  • If you have not, please join our official Homebrewing Facebook Group!

    Homebrewing Facebook Group

Crashing for clarity

Homebrew Talk

Help Support Homebrew Talk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

tchever1

Member
Joined
Sep 17, 2015
Messages
20
Reaction score
0
I am fairly new so I need some advice. Is crashing (sitting a completed carboy in 40 degree for a couple days) to clarify a dry hopped IPA ( Sip of Clone) a good or a bad idea? will I settle some magic haze and ruin it ?:confused::confused:
 
I am fairly new so I need some advice. Is crashing (sitting a completed carboy in 40 degree for a couple days) to clarify a dry hopped IPA ( Sip of Clone) a good or a bad idea? will I settle some magic haze and ruin it ?:confused::confused:

You should be totally fine doing this. Whichever way you cut it, a dry hopped beer will almost never be as clear as a beer that isn't dry hopped, but you shouldn't lose any of the hop character by cold crashing. You also won't get rid of chill haze in just a few days, so if you are trying to do that I'd say wait until it gets really cold then use some gelatin. :mug:
 
I have not seen 1 piece air locks suck anything into the fermenter as long as its filled up to the line and not higher. 3 piece air locks will definitely suck the liquid in it into the fermenter.
 
You should be totally fine doing this. Whichever way you cut it, a dry hopped beer will almost never be as clear as a beer that isn't dry hopped, but you shouldn't lose any of the hop character by cold crashing. You also won't get rid of chill haze in just a few days, so if you are trying to do that I'd say wait until it gets really cold then use some gelatin. :mug:

It's my understanding that the yeast in suspension will absorb some of that dry hop oil goodness and take it with it when the cold crash drops the yeast out.
 
Take the air-lock off and replace with some sanitized foil. No suck back possible. Problem solved.

I crash all my beers in the primary to 32F before fining and kegging.

Cold Crashed Beer.jpg
 
Take the air-lock off and replace with some sanitized foil. No suck back possible. Problem solved.



I crash all my beers in the primary to 32F before fining and kegging.


I would be hesitant to do this, personally, for fear of introducing oxygen to the beer.

At the end of the day, there will be some suck back from an airlock, but if a little starsan gets into 5 gallons of beer, it shouldn't affect the taste or quality of the final product. Or better yet, throw some vodka into the airlock. To me, I'd rather take that chance than to know I'm letting oxygen in, even if it isn't much.
 
The oxigen would be above the co 2 that is above the Beer, but do it how you like.
 
I would be hesitant to do this, personally, for fear of introducing oxygen to the beer.

At the end of the day, there will be some suck back from an airlock, but if a little starsan gets into 5 gallons of beer, it shouldn't affect the taste or quality of the final product. Or better yet, throw some vodka into the airlock. To me, I'd rather take that chance than to know I'm letting oxygen in, even if it isn't much.

If things are getting sucked back in there is air getting in along with whatever's in your airlock. The volume of fluid in the airlock is much smaller than the volume or fluid/air that will enter the carboy.

My preference is to take the airlock off when it is clearly not doing it's job anymore. It only functions with positive pressure from within the vessel. Starsan or vodka in these tiny amounts will have little to no impact on the beer but why bother having them sucked back when the airlock is no longer an airlock.

Without positive pressure of CO2 to the carboy during chilling there is no way to avoid air getting in if you cold-crash. All the solutions to target this conceptualized problem of air entry during crashing on the small scales of my fermentors have that objective.

This is a simple way of keeping particulate out, avoiding unwanted airlock fluid entering the beer while accepting the increase in partial pressures of O2 in the headspace of the carboy for a 24 hour period of time.

Keeping the airlock on does the same but you get the starsan and the increased O2 partial pressures into the carboy. All its doing at this time is keeping out particulate.
 
ChelisHubby was echoing conventional wisdom. Can you elaborate on what's going on?

CO2 is heavier than air, but gasses mix. Even if they are not "stirrred", any gas will expand as far as it can to fill its container.

So, the conventional wisdom is that CO2 forms a protective blanket. That's only true if there's an airtight airlock there. With no airlock, the CO2 absolutely will leave that container.

That's what kombat was intimating.
 
ChelisHubby was echoing conventional wisdom. Can you elaborate on what's going on?

Fortunately for mamallian life CO2 will not form a blanket. If this were the case the lower 0.2% of the earths atmosphere would be CO2 and none of us would be here to discuss things like brownian motion and kinetic theory of gasses.

Translational_motion.gif
 
ChelisHubby was echoing conventional wisdom. Can you elaborate on what's going on?

Gasses don't stratify like that - they mix. If CO2 truly sank to the bottom (because it is indeed heavier than O2), then how are we all breathing right now? Shouldn't whatever CO2 is in the atmosphere sink to the bottom, pushing the oxygen up higher in the atmosphere, thus suffocating all of us who don't happen to be atop a skyscraper?
 
Without positive pressure of CO2 to the carboy during chilling there is no way to avoid air getting in if you cold-crash.

That's precisely why I've stopped cold-crashing my beers in the primary. I let them ferment out in the carboy, then rack them directly to a keg that goes into the fridge, and hooked up to CO2. The only thing filling the headspace of that keg is CO2, protecting the beer from oxidation. If it's being stubborn about clearing up, I'll hit it with a little gelatin. 2 days later, I pour out a few ounces of yeast/trub, and I get crystal-clear beer.
 
What about this? [ame]https://www.youtube.com/watch?v=1PJTq2xQiQ0[/ame]
 
That's precisely why I've stopped cold-crashing my beers in the primary. I let them ferment out in the carboy, then rack them directly to a keg that goes into the fridge, and hooked up to CO2. The only thing filling the headspace of that keg is CO2, protecting the beer from oxidation. If it's being stubborn about clearing up, I'll hit it with a little gelatin. 2 days later, I pour out a few ounces of yeast/trub, and I get crystal-clear beer.

Thus far, oxygenation of the beer as a result of this process has not become apparent either to my taste-buds nor the limited number of judges that have critiqued my beer.

I am willing to accept the theorized risks until they manifest as actual flavors of oxygenation I or others more qualified are able to detect.

For the time being on the scales I brew at it is a problem that I don't seem to have.
 

That's pretty neat! From the comments on youtube, that was sulfur hexafluoride. It's a LOT heavier than air (5x). But it would, eventually, mix. I.e., by the end of the day that foil boat would be sitting on the bottom of the clear container.

Diffusion rate of gasses into air is pretty deep physics and math. It's a classic mixing problem (diff eq.). Obviously, if the opening to atmosphere is really small, that's going to slow down the diffusion. But I'll take a guess at the time it takes for the concentration of the gas to halve (time constant) assuming a nice wide opening between a container and atmosphere.

Gas / Molecular weights (approx) / time constant:
  • Air / 29 / na
  • CO2 / 44 / 1 hour
  • Sulfur hexafluoride / 146 / 5 hours
 
It's my understanding that the yeast in suspension will absorb some of that dry hop oil goodness and take it with it when the cold crash drops the yeast out.


That's what I was trying to minimize following the yeast immobilization exbeeriment on here:

https://www.homebrewtalk.com/showthread.php?t=404698


(in general though, I think any effect of floc on hop lipids and oil is fairly minimal, as a lot of us surely have successful cold-crashed IPAs, dry hopped or not)
 
Ive always put some (sanitized) cellophane over the carboy opening and reinserting the airlock when cold crashing to stop suck back when cold crashing. Never had an issue.
 
Press and seal works the best. No air in or out. It inflates or deflates as needed
 
Back
Top