Cold Crash Temperature Control

[DrSanta]

I've been brewing for over a year and I have yet to cold crash a beer. I figured it was something that I'd do if I had lagering equipment to chill a beer in nice and cold in a contained environment, but I live in the city and the chances of me obtaining and utilizing such equipment is slim to none right now.

However, it's getting cold out there theses days and I have a pantry with very thin walls. I'm thinking of cold crashing a beer that is in exactly the right point of fermentation (ie: it's done) and I'm excited to give a shot.

My question is this: Does it matter if the temperature fluxuates about 15-20 degrees, so long as it stays cool outside? This week it's supposed to be in the high 30s at night and high 50s during the day. Will the fluctuation in temperatures become a problem?

Also there's a window in the room so I'm thinking of tossing a blanket over my food grade plastic Ale Pale bucket. Is that being overcautious when it comes to light hitting hops?

Thanks!

 

[cchotz]

Yes it matters. Temperature is very important to proper fermentation and ensuring your yeast is healthy. Temperature fluctuation of 5 degrees or more can create off flavors and contaminate your beer. They do make bands that go around a carboy to control the temperature. I have never used one, but they are relatively inexpensive. I place my beer in the pantry where the temperature stays fairly consistent. I do wrap a blanket around mine. Both to prevent light from hitting it and also to keep the temperature of the beer consistent. The blanket helps keep the temp from fluctuating too much or too fast during a really cold night or really warm day.

 

[Justibone]

I think that temperature fluctuations are more worrisome during the primary fermentation. If you are just hoping the cold will crash the last of the yeast and help clear (and condition) your beer, I am not certain that will do the trick.

I have not tried it myself, of course.

 

[DrSanta]

Yes, I can confirm that primary fermentation is complete.

So the question is, does temperature fluctuation alter the taste of the beer after that? Perhaps I should put it into a secondary and THEN stick on the pantry?

 

[Justibone]

So the question is, does temperature fluctuation alter the taste of the beer after that?

I don't know.

I don't think so, but I don't actually know.

 

[TheDom]

Once you're sure primary fermentation is done, I think it'd be ok. Temps in the 30s to 50s are way below normal ale yeast temps, and should keep them fairly inactive. If your temps would go up into the 70s or 80s I'd be worriconcerned, but those temps should be fine. I'm not 100% sure, since I've never crashed with that big of a temp range, but I don't see how it could hurt.

As an aside: temperature fluctuations will NOT contaminate your beer. Temp changes during primary definitely can create off flavors, but it will not cause contamination. Only poor sanitary procedures lead to innoculation with less than desirable organisms.

 

[Bithead]

I'm contemplating cold crashing in my garage when temps get a bit lower. My only concern is suckback. https://www.homebrewtalk.com/f163/temp-reduction-suckback-lets-brainstorm-152658/

 

[ihearthops]

I'm contemplating cold crashing in my garage when temps get a bit lower. My only concern is suckback. https://www.homebrewtalk.com/f163/temp-reduction-suckback-lets-brainstorm-152658/

If you're concerned about suckback, then use a "S" style airlock versus a three piece -- the S style works in both directions, in or out.

 

[TheDom]

Or fill your airlock with vodka, won't hurt to have a little extra alcohol in your beer. That being said, I've never noticed a problem with suckback, and I usually cold craah from 65 to 35.

 

[DrSanta]

Thanks folks. I had figured that temperature variation wasn't a big deal after the yeasties had done their thing, and also if we were talking about temperature changes where both high and low ranges were below the standard Ale yeast fermentation range.

I'll stick it in the pantry tonight.

 

[DHenry]

Very late to this thread, but I'm thinking about doing the same, but with the barrel outside. Our nighttime temperatures are no lower than 42F and daytime is no higher than 52F. Was thinking of throwing a wet towel over it to help keep it cool, and it of course will be completely in the shade.

My question is will this fluctuation in temperature outweigh any benefits from cold crashing? Primary is completed, has been in for just over 2 weeks now, so from what I can tell, cold crashing at this stage will just help clarity.

However, I'm aware that yeast can react badly to temperature change: does this also apply to (essentially) non-active yeast temperatures?