How fast to cold crash?

[Tom R]

John Palmer writes that cooling faster than 2 deg F per day can stress the yeast and cause off flavors.
My weisbock is at 65F right now and ready to crash, but I'd rather not spend 17 days getting it down to 30F unless it really makes a difference.

How fast do you crash your beer?

 

[Stonehenge360]

I could be mistaken, but I think the 2F per day recommendation is only during active fermentation. When it’s ready for cold crash most of the yeast should be done working and should not cause any off flavors

 

[BrewnWKopperKat]

John Palmer writes that cooling faster than 2 deg F per day can stress the yeast and cause off flavors.

Link to where he wrote this?

 

[Tom R]

How to Brew, 4th edition, page 95. In discussing cold conditioning after fermentation has completed:

"...The point of slow cooling is to prevent thermal shock of the yeast cells and subsequent excretion of fatty acids and other lipids. These lipids can interfere with head formation and will rapidly oxidize, creating stale flavors."

 

[Jim R]

I usually drop the temperature slowly over 1-2 days if for nothing else but to prevent my refrigerator from running continually for a prolonged period of time since it is also my fermentation chamber.

 

[michaeltrego]

I usually drop it 5 degrees and wait 3-4 hours then repeat until it gets to 40.

 

[Dland]

If you are attempting to ramp down for lager, you're doing better than a lot of folks who make good beer.

I have lager ramp up, D rest& spund ramp down pretty well for my rig. Temps are not manged "by the book", but as well as can be easily done with equipment at hand.

For instance, I don't worry if it drops from 50 to 30F in final crash, temps were managed well in zones when yeast were active. Can't really tell the difference from when I took the (not trivial) effort to ramp cash down slowly.

The lager comes out great, lagering long enough works every time..

 

[day_trippr]

Hah! None of my three brewery fridges are powerful enough to get close to Palmer's concerns (assuming he still has them).
It takes ~40 hours in any of my three fridges to drop 10+ gallons in a pair of carboys from ~68°F down to 34°F.
More like a slow fall than a crash

Cheers!

 

[Tom R]

Hah! None of my three brewery fridges are powerful enough to get close to Palmer's concerns (assuming he still has them).
It takes ~40 hours in any of my three fridges to drop 10+ gallons in a pair of carboys from ~68°F down to 34°F.
More like a slow fall than a crash

Cheers!

If my arithmetic is correct, Palmer is suggesting cooling at a max of .084 degrees per hour, and your fridge can manage .85 degrees per hour. So you're actually really "haulin' 'taters" as my rancher friend says!

 

[day_trippr]

lol! Oh - per day! Yeah, that I can beat!

That sounds more like settling a lager into its cold fermentation phase. Not crashing out a hopped-up ale.
But it's been well over a decade since I last read "HowTo Brew" so I don't fully recall the context.

Hopefully it's not in one of the editions he was still espousing the use of "secondary fermentation"...

Cheers!

 

[Tom R]

No racking into a secondary in this edition.
I remember how adamant Dave Miller was about the absolute need to use a secondary in his homebrew book I bought circa 1990. I guess we all live and learn..

 

[jddevinn]

For a lager a step of a couple degrees an hour. For a ale that I'm done fermenting and ready to transfer.... as fast as the glycol system will pull it.

 

[Tom R]

I'm running a jacketed fermented with glycol, so I can crash it pretty hard, and always have in the past.
Just trying to keep upping my game in pursuit of better beer.

 

[Vale71]

0.6°C per day for lagers (because you already start at a lower temp) and 1.0°C per day for ales. I use an Auber programmable controller to achieve a steady rate.
Most ales are ready by the time they reach target temperature, lagers are of course lagered a bit longer.

 

[Vale71]

I could be mistaken, but I think the 2F per day recommendation is only during active fermentation. When it’s ready for cold crash most of the yeast should be done working and should not cause any off flavors

Why would you start dropping temperature while fermentation is still ongoing?

 

[Vale71]

Just out of curiosity, all you "race-to-the-finish" cold-crashers, what advantage do you expect from the fastest possible chilling?

 

[Dland]

In my case, it is simply a matter of limitations on my equipment, combined with laziness, I suppose one could say, not any sense of hurry. With cooling achieved with external flat hose wrapped on conical & home made glycol chiller, dropping slowly from around 50 to 30F after spunding in kegs is kind of inconvenient.

I have done it, wrapping hose around the two kegs, then insulation, but lately have had a primary fermentor going almost continuously also.

The chiller could handle two pumps and another hose, might get to rigging that someday. Or maybe I could pick up another chest freezer, and use as dedicated slow crash chamber. I already have a 12 keg dedicated beer unit I keep at 30F though, so I'll probably not buy a new one just for crash chamber. They do show up cheep or free occasionally, that might be worth it.

But since niether I or anyone who has tasted my lagers has been able to tell the differnece between slow crashed and ones that had the 20 degree drop, there is not a lot of incentive.

 

[jddevinn]

Just out of curiosity, all you "race-to-the-finish" cold-crashers, what advantage do you expect from the fastest possible chilling?

No advantage other than I can one click a program instead of going through the effort of a stepped cooldown. With positive CO2 pressure I don't think it matters.

If anyone has a reason NOT to crash fast I'm listening!!!

 

[SanPancho]

0.6°C per day for lagers (because you already start at a lower temp) and 1.0°C per day for ales. I use an Auber programmable controller to achieve a steady rate.
Most ales are ready by the time they reach target temperature, lagers are of course lagered a bit longer.

And what is the reasoning for the super slow rate- is it as describEd by Palmer? Thermal shock?

id think once done fermenting the yeast would mostly be dormant, and not susceptible?

 

[Nate]

We've always crashed as fast as possible and have made some awesome beer. Like others have said, if your yeast isn't doing much anyhow, not sure how you'd get off flavors but it would be interesting to hear the thought process of this.