[rbowers]

Does anyone know much about crash cooling ales?  I have a lager in my keezer now lagering for  6 weeks at 34F and wanted to put my two other ales (currently in the primary but likely done fermenting) in kegs and crash cool them to help clear them up.  Can these simply be rapidly chilled down to 34 degrees or is it better to slowly drop the temp down?  How long will they need to cool for- ideally I would just leave them in the keezer, force carbonate, and drink when ready.
Also one is going to be aged on some bourbon oak cubes in the keg for anywhere from 1-4 weeks depending on flavors obtained- can this be done at such low temps or would it be preferable to do this at room air temp and then crash cool?
Are there consequences to having rapidly shifting temps (32-68F) to beers after fermentation is complete?

[blatz]

no harm in rapid - that's how I do every ale - racked to kegs, then the kegs go into the 'on deck' chest freezer at about 36df where they sit until tapping, which may be a few weeks for the first one and a few months for the second.

[Kit B]

You can crash the yeast, as you've stated.
But, you'll probably find that the aging will work better at fermentation temperatures.

[James Lorden]

Rapidly chilling any yeast is suposed to have the ill effect of causing some ester production (according to a recent BrewStrong episode and in the book Yeast) That said, I have never noticed any ill effect from crashing an ale - probably because ester production is already a mojor flavor component.

If using oak to mimic a barrell then I would note that when a beer is in a barrell it's usually sitting at cellar temp so that is the temperature that I would want to shoot for.  Depending on how long you plan to age on the cubes and if cellar temps are used (as opposed to refrigeration temps), I might rack to a secondary to remove the beer from the yeast to avoid any off flavor developement.

[blatz]

Rapidly chilling any yeast is suposed to have the ill effect of causing some ester production (according to a recent BrewStrong episode and in the book Yeast) That said, I have never noticed any ill effect from crashing an ale - probably because ester production is already a mojor flavor component.

James - is this true after fermentation is completed?  I could completely understand if crashed during fermentation, but if we're talking 2 weeks after gravity stopped changing, it does not compute.

BTW - totally agree with oaking at room temp - seems that beer picks up flavors (dryhop, etc) better at warmer temps than colder.

[redbeerman]

no harm in rapid - that's how I do every ale - racked to kegs, then the kegs go into the 'on deck' chest freezer at about 36df where they sit until tapping, which may be a few weeks for the first one and a few months for the second.

+1  Now that I have my lagerator built, crash everything, although I do dryhop at warmer temps (65F or so)

[bluesman]

Crash cooling after primary fermentation is complete is recommended. The rate of cooling in a normal chest freezer of refrigerator set at 34F should lower the beer temp down over the course of 24-48 hrs depending on the thermal mass of your containment. As long as anaerobic metabolism has ceased, it shouldn't disturb the yeast. I haven't experienced any off-flavors from this method.

[andyi]

Are you crashing in primary or racking to secondary then crash cool?

[bluesman]

Are you crashing in primary or racking to secondary then crash cool?

I use both methods with great success.

[James Lorden]

I completely agree with Bluesman that I have never noticed any percieved off flavors in any beer that I've crash cooled and I do crash cool alot.

I am certain however that Chris White and Jamil have pointed out that there are certain esters excreted during crash cooling.  I also read that in brewing science and practice it says that crashing might cause the yeast to secrete a enzyme that can harm head retention but that is second hand information.

Now perhaps the rate of crash cooling that these sources are talking about are differenct then what a homebrewer might achieve or the levels are not readily percieved since they quite low not sure.

Bottom line is that I agree, go ahead and crash cool - there are some side affects but they aren't noticeable to most peoples beer.

[davidgzach]

Haven't heard of the enzyme that harms head retention in crash cooling.  I have heard that head retention will suffer if you bring the temp up and down several times however. 

IMHO if you are going to crash cool, why bother with a secondary?  It's just another transfer and another way to introduce bacteria or Oxygen. 

Dave

[rbowers]

Thanks for all the good info.  I went ahead and put the primary into the keezer yesterday at 34F.  I guess we will see how it goes.  After cooling I'm going to rack to a corny and treat as a secondary with addition of the bourbon oak cubes.  This will be left to sit at room temp for a week or two with frequent sampling to get the oak flavor right.  I'll keep you posted

[mrcceo]

When I crash cool an ale I hold it at 40 degrees which is the temperature which yeast will drop out of suspension for a few days before transferring it to a keg.  It puts a little less stress on the yeast and still achieves the same result.

When crashing a lager the recommendation is 3-4 degrees per day until you reach lagering temp.  This will keep the yeast active although at a much lower rate so they are still cleaning up the beer during the lagering stage.