cold crashing help

1) I don't have any science behind this one. I put my carboy in the fridge for 3-4 days before racking to bottling bucket. Others probably wait even longer but this works for me. YMMV.

2) There will be more than enough yeast still in suspension to carbonate the bottles.

3) You can bottle at the lower temp and allow them to warm to room temp once finished.

4) You should calculate your priming sugar using the warmest temp incurred during fermentation. (if you fermented at 65 then crashed to 38, use 65 in the calculator)

5) It's not a necessary step in the process. Beer will still clear up anyway given enough time. I tend to brew hoppier styles so I almost always cold crash to assist in settling out the dry hops.

 

1. Your 24-48 hours are probably on the short side. My experience . . . more is better. I have taken some beers as long as 21 days at 39°. Consider that while cold crashing the beer is also conditioning, so you aren't wasting time.

2. Ditto above: My three weeks of cold crashing had plenty of residual yeast left over, absolutely no problem with bottle carbing. Plus, this was my clearest beer ever.

3. Ditto above.

4. Ditto above. This is to account for residual CO2. Not all CO2 comes out the airlock, a portion is in equilibrium with the atmosphere and that's what remains in the beer. Generally speaking this will be the highest temp you fermed at, or the temp you use a bottling bottle. The higher the temp, the more carbon dioxide escapes. If you subsequently chill the beer there will be no more CO2 entering . . . thus use your highest temp that allowed the CO2 to escape (airlock/bucket). Suggestion: spring for a simple digital scale to weigh your priming sugar.

5. Time and cold temps really help to clear beer (keg or bottle). Although not strictly necessary, I recommend cold-crashing. Also, if interested in finings, here's a pretty good article.

 

OP: Just want to add... cold crashing does hasten Yeast settling (flocculation). Proteins and Trub? Not so much.

 

To the extent that the non-clarity is due to suspended yeast, yes.

Proteins: yes, whirfloc (in the boil)
Trub (like hop particles and husk particles): Time and Gravity are what I use

 

There are a number of post fermentation finings that folks add to their beers to clarify them. For example: gelatin, isinglass, biofine, polyclar, …

I personally have never used any of the above products (I only use Irish Moss flakes in the kettle). Hopefully some other BAs could provide some suggestions on which fining is ‘best’ for you?

Cheers!

P.S. Time and gravity will clear any beer if you are patient enough.

 

^^^^^ This, pretty much.

 

Don't know that I'd bother transferring to secondary. If it were my beer, I might just go ahead and bottle it.

After giving them a week or so at room temp to carb up, move your bottles to your freezer or fridge. Let them sit for a few weeks, at least, to clear/condition.

And, as added advantages: (1) you'll be getting less O2 pickup by not transferring to secondary (2) the bottles will be sitting @Cold, so you'll be slowing down any staling reactions.

 

+1 to what Alan posted: you can ‘cold crash’ your beers in the bottles (post carbonation).

Cheers!

 

What kind of benefits occur during conditioning in cold crash other than clearing? I am currently cold crashing a 9% ale and I'm worried it will have too much heat. Can the cold temps help with that?

 

I helps to think of cold crashing and lagering (cold conditioning) as different things.

Cold crashing (short term) accelarates yeast clearing. Lagering (longer term) allows time for high weight proteins and tannins to settle out. The cold doesn't help these things settle any faster, but it does slow down staling while they do.

If by too much heat you mean fusel alcohols, time in the presence of yeast (and certain acids) will mitigate that somewhat, turning some of them to esters. To the best of my knowledge, these reactions happen faster at warm temps rather than cold temps.

 

This is in the context of "new beer". After primary fermentation, to include a d-rest, typically your beer has much farther to go before being ready to serve. Example: I tasted the grav sample of an IPA today that was 15 days old - - very unspectacular. It needs time to mature. My technique is to cold-crash (1-3 weeks) to clear much of the yeast. Then a dh period (7-12) days before considering bottling. I could let it sit for this entire time in the mid 60s and it would mature . . . rather I'm trying to settle some yeast. This is what I meant when I said cold-crashing is "not wasting time".

IMO this takes advantage of the 3-4 weeks after primary fermentation is complete and before bottling/kegging. I use kegs which give a few advantages with transferring/chilling/dh'ing/carbing.

I believe mitigating fusel alcohols is best done by properly controlling primary ferm temperature. This should not be dependent on the ABV of the brew, rather the temp the yeast were working under (i.e. a low ABV beer could also have fusels). To the best of my knowledge, cold-crashing/lagering will not correct this problem. If you kept your primary temp under control you should be good here. I've had commercial and homebrews well above 8% where the alcohol level was not detectable (until it passed the blood-brain-barrier!). Would welcome others experiences in this area.

 

haha, if you get this far all that these guys have said is excellent.

I've only cold crashed once so far. Did it at 38F for 48 hours. Moved the fermenters 100ft before transferring to bottling bucket for bottling. Bottled cold, calculated priming sugar on highest temp during fermentation. From the bottle or two I've opened, I'm getting very clear beer that seems to be carbonating up quite well.

I think cold crashing has been the most satisfying thing I've done combined with fermentation temp control. good stuff.

 

Colder temperatures cause larger protein-polyphenol particles to form. Stokes law says those larger particles fall out at a higher velocity. The colder you lager at, the quicker the beer will clear and the smooth lager flavor develops.

I have been lagering colder over the years. Now I am using -1C, and like the results.

 

This is true. Going really cold (about 35F or lower) does cause the aggregates to form. And at any given temp, heavier particles settle faster than lighter ones. At higher temps, these colloidal aggregates (chill haze) don't form and their non-aggregated components are not visible.