Cold crashing

[meirion658]

Hi all just about to come to the end of fermentation and dry hopping and looking to keg this time round.

How long should I cold crash for and what sort of temperature should I be looking at. Do I gandually decrease the temp or just take it down in one hit?

 

[pms67]

Hi all just about to come to the end of fermentation and dry hopping and looking to keg this time round.

How long should I cold crash for and what sort of temperature should I be looking at. Do I gandually decrease the temp or just take it down in one hit?

I just go straight to 4 degrees for 48 hours, works a treat for me 👍

 

[terrym]

But if you haven't got a fridge then just find a cool place, and put the FV there. I usually dry hop for six days, four in the warm, two in a cool place. And by then most of the hops, sometimes all, have dropped.
I actually have a fridge for brewing but don't use it to crash cool my beer at the end of the dry hop, except perhaps in the middle of summer.

 

[Simonh82]

The colder the better for cold crashing. According to Charlie Bamforth who runs the brewing programme at University of California Davis, one day at -0.5°C is better than a month at 3°C. The lower the temp the more proteins will come out of solution and drop out. 24-48 hours should be fine in general. I often don't get a chance to bottle when I plan, so after a couple of day, I will bump the temp back up to 8-10°C to give the fridge a bit of a rest.

 

[Gunge]

The colder the better for cold crashing. According to Charlie Bamforth who runs the brewing programme at University of California Davis, one day at -0.5°C is better than a month at 3°C. The lower the temp the more proteins will come out of solution and drop out. 24-48 hours should be fine in general. I often don't get a chance to bottle when I plan, so after a couple of day, I will bump the temp back up to 8-10°C to give the fridge a bit of a rest.

What happens to yeast if the beer freezes? I've only recently started controlling temps with a fridge.. the first time I used it, it overshot and my ale had a skin of ice on top! Didn't go further than that but what if it had and the whole lot froze - dead yeast?

 

[foxy]

Freezing will not kill the yeast, as Simon says quoting from Charlie Bamforth -1 degree C for lower alcohol beers and -2 for stronger beers for 24 hours. It also depends on water treatment, pH, salt additions and the process whether it clears without finings. I find mine drops clear after a week of completion of fermentation, if not its the cold crash.

 

[big yogi]

Guys, when cold crashing do you keep it in the primary or secondary?

 

[Simonh82]

What happens to yeast if the beer freezes? I've only recently started controlling temps with a fridge.. the first time I used it, it overshot and my ale had a skin of ice on top! Didn't go further than that but what if it had and the whole lot froze - dead yeast?

The alcohol content of the beer should protect it from freezing generally. I have my temp probe for my inkbird hanging in the air space of the fridge, so I know that when I set it to -0.5, it won't get lower than that. If it is taped to the fermenter, then there is a chance that it could overshoot and freeze over.

There is a hot debate going on in the brewing equipment forum at the moment over just this but I think if you area cold crashing to near freezing temps, using the air temp and accepting that it might take a little longer to get their is the best option.

Freezing will damage yeast cells but it is unlikely that it would kill all of them. Repeated freezing and thawing would potentially be pretty bad for them though, but you'd be unlucky for that to happen.

 

[BeerCat]

I have frozen a DJ full of yeast solid. Was fine. My fridge is set to -1c. If the beer does freeze a little either bottle like that or let it thaw first.
Apparently you can dry yeast and freeze for up to 10 years.

 

[WierdFish]

I have a brew that's at the end of primary now and am considering cold crashing. I've never done it before so am reading this thread with interest. I have a brew fridge currently at 24oC

My plan is, finish primary, cold crash for a couple of days, transfer to secondary FV and add priming sugar and immediately bottle. Then back in the fridge at 22oC for a few weeks before sampling.

Does that sound about right?

 

[Simonh82]

Guys, when cold crashing do you keep it in the primary or secondary?

Yes, I've never yet used a secondary vessel.

 

[big yogi]

Yes, I've never yet used a secondary vessel.

cheers mate, i read that you put into a secondary.

My way of thinking, the less you have to touch it, the less chance for infection:thumb:

 

[foxy]

I have a brew that's at the end of primary now and am considering cold crashing. I've never done it before so am reading this thread with interest. I have a brew fridge currently at 24oC

My plan is, finish primary, cold crash for a couple of days, transfer to secondary FV and add priming sugar and immediately bottle. Then back in the fridge at 22oC for a few weeks before sampling.

Does that sound about right?

That's about it.

 

[Gunge]

cheers mate, i read that you put into a secondary.

My way of thinking, the less you have to touch it, the less chance for infection:thumb:

I've never used a secondary. Unless it's going to be sat on the yeast layer at the bottom of the original FV forever, I can't think of any reason whatsoever to fiddle with it and open up avenues for infection. And I can't see how removing it from the yeast layer hastens clarification; it can only disturb the clarifying process that is already underway. Enlightenment, someone? Not that it would change my routine mind, it's how I've always done it with zero problems and no infections, ever.

 

[Bigcol49]

Guys, when cold crashing do you keep it in the primary or secondary?

Yes :grin:

Some cold crash in a secondary vessel, others simply reduce the temperature of the primary vessel after fermentation is complete.

Colin

 

[terrym]

And I can't see how removing it from the yeast layer hastens clarification; it can only disturb the clarifying process that is already underway. Enlightenment, someone?

I usually rack off, usually about the 10 day stage.
Although the fermentation is substantially finished at that stage, and the beer is clearing there are occasional CO2 bubbles rising from the bottom of the FV and they drag settled yeast with them, that dissipates into the beer, tending to keep it cloudy.
If you rack the beer off then there are no bubbles, and the yeast settles. I usually leave it another 6 days before packaging, when it's almost clear.
So in my view you get clearer beer faster.
And I've not had any signs of infections or the dreaded oxidation as a result of racking off (so far), so for me its worth doing.
Well that's my take on it. :thumb:

 

[big yogi]

Yes :grin:

Some cold crash in a secondary vessel, others simply reduce the temperature of the primary vessel after fermentation is complete.

Colin

Thanks, i will keep in primary for 10 days then crash it for 2.

 

[big yogi]

I've never used a secondary. Unless it's going to be sat on the yeast layer at the bottom of the original FV forever, I can't think of any reason whatsoever to fiddle with it and open up avenues for infection. And I can't see how removing it from the yeast layer hastens clarification; it can only disturb the clarifying process that is already underway. Enlightenment, someone? Not that it would change my routine mind, it's how I've always done it with zero problems and no infections, ever.

thanks mate