Cold crash?

[BeerJ]

Hi guys. I recently checked the gravity of my beer that’s been sat in a temperature controlled fermenting vessel for 7 days. It seems to have finished fermentation but there is still what I believe to be yeast on the surface? I’ve never cold crashed but have the ability to now. Will this help clear the top quicker? If so how low do I go? It’s a british ale that I am brewing . Thanks

 

[Buffers brewery]

Hi @BeerJ I wait until I have 2 SG readings the same taken 2 days apart before cold crashing. I go as low as my fridge will go ( 4C ). It takes a day or so to get the temperature down (depending on volume of beer you’ve got to chill) so I usually leave it for 3 days and transfer on day 4. A day or two more wouldn’t do any harm.

 

[Nottsbeer]

Hi @BeerJ I wait until I have 2 SG readings the same taken 2 days apart before cold crashing. I go as low as my fridge will go ( 4C ). It takes a day or so to get the temperature down (depending on volume of beer you’ve got to chill) so I usually leave it for 3 days and transfer on day 4. A day or two more wouldn’t do any harm.

Does cold crashing cause a pressure difference in the fermenter, resulting in and liquid in the airlock being sucked into the fermenter? I think I saw that mentioned previously but can't find it now. If it does, what do you do to stop this happening? Aiming to cold crash next week.

 

[BeerJ]

Hi @BeerJ I wait until I have 2 SG readings the same taken 2 days apart before cold crashing. I go as low as my fridge will go ( 4C ). It takes a day or so to get the temperature down (depending on volume of beer you’ve got to chill) so I usually leave it for 3 days and transfer on day 4. A day or two more wouldn’t do any harm.

Thanks for the reply. Does the picture of the beer look normal? Normally all the yeast has dropped by now, specially given the fg reading is at 1.006. It’s been sat at 20 degrees the whole time. Is it ok to bottle as it is if I get 2 fg reading the same?.

if I do get a second reading the same I will cold crash it I am just curious whether it matters bottling now

 

[Nottsbeer]

Thanks for the reply. Does the picture of the beer look normal? Normally all the yeast has dropped by now, specially given the fg reading is at 1.006. It’s been sat at 20 degrees the whole time. Is it ok to bottle as it is if I get 2 fg reading the same?.

if I do get a second reading the same I will cold crash it I am just curious whether it matters bottling now

I've had brews that have looked like that. If you get consecutive reading the same over different days then it's probably ready. You could leave it longer for the yeast to clean up the beer a bit if wished. I try not to suck up the blobs when transferring into my bottling bucket (or keg). Out of interest, which yeast did you use?

 

[Buffers brewery]

Does cold crashing cause a pressure difference in the fermenter, resulting in and liquid in the airlock being sucked into the fermenter? I think I saw that mentioned previously but can't find it now. If it does, what do you do to stop this happening? Aiming to cold crash next week.

Yes. Apart from the contraction of the gas as it gets colder, CO2 is absorbed into the beer at lower temperatures. Some ( including me ) collect the CO2 produced during fermentation in a Mylar balloon and use that to feed back into the fermentation bucket during cold crash. Before I did that I just let the bubbler take care of it. It's a slow process so the liquid in the bubbler doesn't get sucked into the beer. Search for "balloons" to find out more. There are a few posts that you might find helpful.

 

[Buffers brewery]

Thanks for the reply. Does the picture of the beer look normal? Normally all the yeast has dropped by now, specially given the fg reading is at 1.006. It’s been sat at 20 degrees the whole time. Is it ok to bottle as it is if I get 2 fg reading the same?.

if I do get a second reading the same I will cold crash it I am just curious whether it matters bottling now

Looks ok to me although I don't lift my lid now to avoid letting air in to my beer. Cold crashing should help settle the yeast out.
Once you're happy fermentation is finished and you've cold crashed you're good to bottle. Don't forget to prime

 

[Nottsbeer]

Yes. Apart from the contraction of the gas as it gets colder, CO2 is absorbed into the beer at lower temperatures. Some ( including me ) collect the CO2 produced during fermentation in a Mylar balloon and use that to feed back into the fermentation bucket during cold crash. Before I did that I just let the bubbler take care of it. It's a slow process so the liquid in the bubbler doesn't get sucked into the beer. Search for "balloons" to find out more. There are a few posts that you might find helpful.

Cheers . I'm only thinking of it for a beer I'm about to add fruit to, still undecided. I will check out the balloon method.

 

[BeerJ]

Looks ok to me although I don't lift my lid now to avoid letting air in to my beer. Cold crashing should help settle the yeast out.
Once you're happy fermentation is finished and you've cold crashed you're good to bottle. Don't forget to prime

I hate opening the lid. I only do it to check gravity. How do you check gravity without lifting the lid? Ispindel? I also don’t worry too much as carbon dioxide is heavier than air so surely it doesn’t just escape when opening the lid

 

[Buffers brewery]

I hate opening the lid. I only do it to check gravity. How do you check gravity without lifting the lid? Ispindel? I also don’t worry too much as carbon dioxide is heavier than air so surely it doesn’t just escape when opening the lid

I have a tap in the bottom of my fermentation bucket so can draw off a sample without lifting the lid. Having a balloon of fermentation gas (CO2) connected to the lid lets gas into the bucket at the top as beer is drawn from the bottom. Check out my (complicated ) set up on my brewday blog for more info.