Jump to content
Coopers Community

Cold Crash Duration


BlackSands

Recommended Posts

"The process involves lowering the temperature of the beer very quickly to near-freezing and holding it for about 24 hours." - Northern Brewer

"If your goal is crystal clear beer, a month should be plenty of time to achieve that."  - foodbeerstuff.com

 

I've just been looking into CC duration recommendations and quickly discovered a very wide variance in opinion.  I know here on this forum 7 days is quite commonly suggested but elsewhere 3-4 days seems to be more the norm. Because I'm in a bit of a hurry trying to build up stock I did a very short CC on my last brew.  10 hours to cool and then around a day and a half of actual CC @0.5ºC, fined with gelatine.  I figured that was better than nothing!   I'd read that if you can get it as close to freezing as possible you can cut your CC time right down. 

That beer has been in bottles 5 days now and after an initial carbonation period in my brew fridge @20ºC they are now in the garage which is currently sitting at 12ºC.  It's cold this morning!   Anyway I notice the beer was crystal clear after a day with barely any visible sign of sediment in the bottles.  They still have a wee way to go with carbonation but having been fermented with Nottingham I'm sure even at these current chilly Winter temps they will get there in another week or two.   Out of curiosity I placed one in the beer fridge which is currently CC'ing a subsequent brew.  I wanted to see if it was going to throw up any hint of chill haze at sub-serving temps.  It appears not.  On the face of this it does seem I need only CC (with gelatine) for a day as Northern Brewer suggest in their quote above -  maybe two days just to be sure.

Those that routinely CC for a week - presumably your experience differs?   🤔

    

 

 

Edited by BlackSands
  • Like 1
Link to comment
Share on other sites

I think, whatever works for you. 

I usually CC for 5 days, if for whatever reason like I’m too busy, it’ll get another 10 days. The ones with the extra 10 days get the clarity that I desire. 

I do not use finings. Well yet, anyway. 

I also CC at 2 c, after a few too many eisbocks. 

I think my current process has the balance between getting beer soon enough and the level of clarity. 

  • Like 2
Link to comment
Share on other sites

Unless you're using a freezer you won't chill a 20 odd litre batch down to near freezing temperatures in 10 hours, it takes more like 24 hours to get from ferment temps to 2ish and another 24 hours to get to zero. The fridge temp might drop that quickly but the beer temp won't. 

I normally leave the beer at these temps for a week, I find a day is pointless as it doesn't really drop much out, but I wasn't using gelatine. The current batch being crashed was still somewhat cloudy after a day, then I put isinglass in it and it was considerably clearer the next day when I added the polyclar. It'll sit there for another few days before being kegged to ensure the polyclar is all dropped out. 

  • Like 2
Link to comment
Share on other sites

I do 3-4 day cold crash. Depending on the beer I am not always going for clarity but for some conditioning. When I want clarity, I drop it down to 1.5c and about a day later maybe 18 hours, I prepare the gelatin and add it. At that point I let it sit for the remaining 3 days to clear up and hopefully keep the yeast and all compacted. I like the 3 to 4 day schedule as it times up well for a 2 week cycle and weekend brewing with a 10 day ferment, which is usually enough time.

  • Like 1
Link to comment
Share on other sites

I suppose it depends on what the outcome is you want. I no longer use a flocc agent as I harvest all my yeasts and for some reason it seems logical to me to have a yeast cake which is all brewing by products ... I like clear beer but now that I keg I crash for a few days then keg and store in the kegger so it is also crashing in the keg which is the logic I use ... my beer is not crystal clear but suits me now but I suppose this raises a question can I use a floccing agent in the keg which will also harden any sediment that falls while in the keg ? 

When I bottled I was really quite anal about clarity so I crashed for longer and the bottles aged for several months before drinking so clarity was great ...  I suppose the issue with kegs is I am not letting them age as long as i don't have to and the beer is just not quite crystal clear but boy is it good ...  

Link to comment
Share on other sites

38 minutes ago, Otto Von Blotto said:

Unless you're using a freezer you won't chill a 20 odd litre batch down to near freezing temperatures in 10 hours, it takes more like 24 hours to get from ferment temps to 2ish and another 24 hours to get to zero. The fridge temp might drop that quickly but the beer temp won't.

No, not in my case. I monitored the actual beer with a digital thermometer - one with a long wire and small probe. 10-ish hours to get to set temperature.  Possibly one thing that is helping is that I bypassed the fridges thermostat which at the coldest temperatures was actually conflicting with the temperature controller.   My controller was set to 1ºC but the fridges thermostat on it's lowest setting seemed to first cut out when it was only down at 5 or 6ºC.   A fridges thermostat should go as low as 0ºC but they're certainly not precision devices and they do have a very wide thermal hysteresis.   Since I bypassed the thermostat I've had no problem getting my beer temperature right down in a relatively short time.   

However, just so I can substantiate this claim, I'm currently measuring a CC I started 2.5hours ago.  The beer was at around 20ºC and is now at 14.2ºC.  Let's see how it goes...  

Edited by BlackSands
Link to comment
Share on other sites

3 hours ago, BlackSands said:

...just so I can substantiate this claim, I'm currently measuring a CC I started 2.5hours ago.  The beer was at around 20ºC and is now at 14.2ºC.  Let's see how it goes...  

6 hrs | 8.5ºC   (fridge: 6.3ºC)

Link to comment
Share on other sites

59 minutes ago, BlackSands said:

7hrs | 6.9ºC   (FV probe: 5.5ºC)

8hrs | 5.5ºC   (FV probe 4.1ºC)

 

Looks like the beer will be in the CC 'zone' by the time 10 hours is up.  I was thinking to get as close to freezing as possble but just read that this could compromise yeast health... not what I want for bottle conditioning/carbonation... 

🤔

 

  • Haha 1
Link to comment
Share on other sites

@BlackSands but are you not in freezing NZ where ambient is 8 degrees on the best of days ?  In a normal climate like sunny Queensland where Kelsey and i live it is always 28 and sunny  so the fridge takes longer to get to near freezing.  For you to get to near freezing you use a heat belt.    🤣

Edited by MartyG1525230263
  • Haha 3
  • Confused 1
Link to comment
Share on other sites

1 hour ago, MartyG1525230263 said:

@BlackSands but are you not in freezing NZ where ambient is 8 degrees on the best of days ?  In a normal climate like sunny Queensland where Kelsey and i live it is always 28 and sunny  so the fridge takes longer to get to near freezing.  For you to get to near freezing you use a heat belt.    🤣

Actually... I did think of that!   Where I live it was a chilly 12ºC when I first kicked this CC off today.  "Warmed" up to 15ºC later in the day but in all seriousness ambient temps could be a factor though I think the fridges insulation would largely nullify that.  I do however think, based on my experience that bypassing your fridges thermostat is a really good idea for all those that use a fridge (as opposed to  freezer).

At 10 hours my brew is now at 1.8ºC down from 20ºC.   I think that says it all.  Much quicker cooling than others (i.e. Otto) have reported.  Of course I guess you could argue... 'what's the hurry?"  

😎 

 

    

Edited by BlackSands
Link to comment
Share on other sites

42 minutes ago, MartyG1525230263 said:

well it is called a "cold crash" not a "cold moderately fast" the crash sort of, no definitely,  implies done at speed ... 

Excellent point!  👍

Anyway, watched a bit of telly an then added the gelatine.  Beer at target temp of 1ºC.    

Edited by BlackSands
  • Like 2
Link to comment
Share on other sites

I find the ambient temperature affects it here. I usually set mine to zero (lagers I do at 3 degrees), which at this time of year is easily achieved, but in summer it struggles to get down that far. This is with the temp probe left in place taped to the fermenter. As a result, in the warmer weather I normally take the probe off when I do the cold crash and change the differential to 2 degrees. The fridge itself easily gets down there and doesn't have to run constantly. I imagine the beer is sitting somewhere between 0 and 2 degrees once it equalises. 

I think the term cold crash or crash chill is more of a way of differentiating it from a ramp down over a few days like I do with lagers, rather than "chill it as fast as possible".

I don't think a day is all that slow anyway, or that there is any advantage to speeding it up, and when you have a fridge that can get to those temps on its own, or in the case of mine make 25 litre beer slushies if it's on its coldest setting without a controller, I don't see a need to bypass anything. I can understand it in your case of the thermostat limiting it from getting that cold though. 

  • Like 1
Link to comment
Share on other sites

Sometimes my CCs are only a day at 2-3degC

Takes about 16hours to get down to that temp.

Gelatine added to FV when at 10degC.

Last  brew was like this - the bottles were  clear and firm after a week in the bottle.

Thats Notty for ya though, reliable as anything!

Have had one brew ice up on top after 5 days at 1degC, so don’t set the fridge so low any more.

Wish my tax return would hurry up!!

Cheers

James

  • Like 1
Link to comment
Share on other sites

Calibration was the first thing I did when I got my Inkbird.   There was a 0.7ºC difference between it and a digital thermometer for starters but I of course adjusted the calibration so that it reflected the actual beer temperature while it's sensor probe was taped to the side of the FV.   This however isn't perfect because it appears to be non-linear as the temperature drops.  I just discovered the temperature differential between the actual beer and probe was close to 2ºC at fermentation temps but the difference between sensor and beer temp was only a little over 1ºC at CC temps.   There's a number of variables in all this of course and one of them will be the effectiveness of whatever insulation you use on your temperature sensor probe when strapping it to the side of your FV.   

In practice is not really a big deal, as long as it's pretty close at fermentation temps, but perhaps something to be aware of when you are calibrating.   

Link to comment
Share on other sites

9 hours ago, James Lao said:

Sometimes my CCs are only a day at 2-3degC

Takes about 16hours to get down to that temp.

Gelatine added to FV when at 10degC.

Last  brew was like this - the bottles were  clear and firm after a week in the bottle.

Thats Notty for ya though, reliable as anything!

Have had one brew ice up on top after 5 days at 1degC, so don’t set the fridge so low any more.

Wish my tax return would hurry up!!

Cheers

James

Yeah...  the brew currently conditioning was fermented with Notty.  It appears to be crystal clear with only a day and a half CC.   I chilled a bottle right down to see if it was going to throw up a chill haze but it's looking pretty good at fridge temp.   

As an aside, I often read folks making claims about their wonderful beer clarity, many claiming such without the need for finings or CC.  The extent of the beer's clarity doesn't mean a whole lot unless the temperature is also specified.  I think most brewers can easily achieve crystal clear beer at room temperature but it's how it looks at serving temperature that's important.  And, 'serving temperature' itself is a variable. English brewers for example probably tend to judge their ale's clarity at 10 - 14ºC!   I consider fridge temp (say 4 -5ºC) as a a more applicable reference temperature for judging clarity.

My current brew used M42 yeast but I have a hunch it will be very similar to Notty given that the two strains could well be the same yeast, however it's not just the yeast that CC is settling out.  It's more those stubborn chill-haze forming compounds that are problematic for clarity.  Anyway, I have plans to get another brew going so the CC on this one will be a short one too.  If I can get the job done with the beers I brew in a day or two then there's really no point in tying the fridge up unnecessarily!        

  • Like 1
Link to comment
Share on other sites

  • 2 months later...

I've just done a couple of smaller AG batches recently after a doing a few extract (and one partial) brew. One thing I've noticed with both these AG brews is the speed of clarification is a lot quicker than the previous extract batches... which actually didn't fully clear in the end.   As mentioned above I've done very short CC's on partial mash brews previously that when bottled were still quite hazy but cleared up well and served up pretty clear though perhaps still a slight hint of haze at fridge temp.  Even longer CC'd partial-mash beers still have a level of haze once bottled, but that usually clears overnight.    In contrast this current AG brew which I put into CC yesterday was already partially clear and even more so at 0.5º when I added gelatine today.  I reckon it could well be bright by tomorrow at this rate and if not, certainly after another day.  Interesting.        

Out of curiosity, after CC'ing, for how ever long you choose to do it, is your brew looking 100% clear at time of packaging or does it get packaged with a slight haze still present?  🤔  

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...