Cold crashing question

[JHulen]

I see other brewers say that they put the fermentor at near freezing for a couple days, and then rack to the keg. I just got a kegging system and I’m wondering if cold crashing the fermentor is necessary since the keg is going in the fridge. Is there a reason that kegging and putting it in the fridge isn’t the same thing?

 

[parjay]

Cold crashing will knock more stuff out of suspension so that you have less gunk to dump with your first couple of pints. I also cold crash colder than my keezer temp, so I feel that it helps my beer clear quicker.

 

[mongoose33]

I have a Spike CF10 Unitank so I can partially carbonate the beer in the fermenter. Cold beer absorbs CO2 more readily than warm beer, so crashing helps that.

I also like seeing the condensation line on the keg as I rack to it.

 

[Blazinlow86]

There's 2 main reasons to cold crash. One is so all the sediment that drops out doesn't end up in the bottom of your kegs and the second is so you can fully carbonate your beer prior to kegging. It's the same process the professionals use. Nothing worse than having to leave your kegs undisturbed for days prior to tapping. To use the unitank as a bright tank requires getting it cold. If your not planning on cold crashing your missing out on what makes the unitank a step up from a standard conical/bucket. Cheers

 

[seatazzz]

You CAN cold crash in the keg, but you're going to lose a couple pints (unless you or your partner particularly enjoys the stench of yeast farts) at the get-go. Cold crashing in the fermenter (no need for secondary for most beers) is the way to go. If you don't have the means to cold-crash (i.e., another beer fermenting in the same chamber), crashing in the keg is possible, although you may want to research closed transfers from crashing keg to serving keg, to leave behind as much yeast/trub/gunk as possible. Clear beer is pretty, yes; but not fully necessary.

 

[Vale71]

The main reason people do this stuff is because somebody came up with the idea mostly out of ignorance and everybody started repeating it so that it somehow became true. From there to becoming a fad it doesn't take that long, especially when the Internet comes into play. Just to set a couple of things straight:

1 - Beer carbonates faster the warmer it is. The speed at which beer absorbs CO2 is determined by the diffusion rate of CO2 in the beer. The laws of physics tell us that the rate increase with increasing temperature (more kinetic energy = more speed). Of course, since the solubility of gases decreases with temperature this means that we'll need to set a higher pressure in the headspace to reach the same amount of dissolved CO2 in the beer, but we'll still get there faster the warmer the beer is.
2 - Suspended solids drop faster the warmer the beer is. This is due to the fact that a liquid's density and hence its viscosity decreases with increasing temperature and it's the viscosity that determines how much resistance the droppping particles will encounter. Lower resistance = higher speed. Water has the so-called "anomaly of water" which means that below 4°C its density starts decreasing again. Still at 0°C density is higher than at 20°C so a warm beer will still clear faster than the same beer cooled to near-freezing temp. Chill haze is a totally different issue as it needs first to form and then to become permanent for it to start clearing at all. For that to happen you do need cold temperatures but on the other hand you also need to keep the beer cold for much longer than a couple of days, i.e. you need proper lagering (or cold-conditioning if you will) for chill haze to clear without filtration, if you just "crash" for a couple of days and then transfer the chill haze will still be there.

Cooling beer very fast also had the issue that the yeast will experience a thermal shock and go dormant. This could inhibit, among other things, flocculation and maturation of the beer (VDKs cleanup and all that stuff) which means your beer might take longer to mature or possibly have serious issues like detectable diacetyl.

I know I'm probably fighting windmills here but I'd still like to put that out, make of that what you will. Cheers.

 

[Gameface]

The main reason people do this stuff is because somebody came up with the idea mostly out of ignorance and everybody started repeating it so that it somehow became true. From there to becoming a fad it doesn't take that long, especially when the Internet comes into play. Just to set a couple of things straight:

1 - Beer carbonates faster the warmer it is. The speed at which beer absorbs CO2 is determined by the diffusion rate of CO2 in the beer. The laws of physics tell us that the rate increase with increasing temperature (more kinetic energy = more speed). Of course, since the solubility of gases decreases with temperature this means that we'll need to set a higher pressure in the headspace to reach the same amount of dissolved CO2 in the beer, but we'll still get there faster the warmer the beer is.
2 - Suspended solids drop faster the warmer the beer is. This is due to the fact that a liquid's density and hence its viscosity decreases with increasing temperature and it's the viscosity that determines how much resistance the droppping particles will encounter. Lower resistance = higher speed. Water has the so-called "anomaly of water" which means that below 4°C its density starts decreasing again. Still at 0°C density is higher than at 20°C so a warm beer will still clear faster than the same beer cooled to near-freezing temp. Chill haze is a totally different issue as it needs first to form and then to become permanent for it to start clearing at all. For that to happen you do need cold temperatures but on the other hand you also need to keep the beer cold for much longer than a couple of days, i.e. you need proper lagering (or cold-conditioning if you will) for chill haze to clear without filtration, if you just "crash" for a couple of days and then transfer the chill haze will still be there.

Cooling beer very fast also had the issue that the yeast will experience a thermal shock and go dormant. This could inhibit, among other things, flocculation and maturation of the beer (VDKs cleanup and all that stuff) which means your beer might take longer to mature or possibly have serious issues like detectable diacetyl.

I know I'm probably fighting windmills here but I'd still like to put that out, make of that what you will. Cheers.

Well this certainly flies in the face of conventional wisdom as well as my 10 years of brewing experience.

I mean I'm not a chemical engineer, so I'm not going to argue that carbonating warmer with a higher pressure is faster than carbonating colder with a lower pressure. But If I want my beer carbonated RIGHT NOW I can crank up the pressure and shake my keg and have fully carbonated cold beer in about 1min.

The advantage of chilling beer to serving temp to carbonate is that you can set your CO2 pressure where you're gonna keep it for serving and get your carbonation exactly right. A unitank is fantastic for this purpose, but a keg is just fine if you're not in too big a hurry.

The idea that beer clears faster at warmer temps is 100% contrary to my own experience. Again, I'm not a Chem-E, so I'll leave any further discussion to people who know better than I do. But Chilling absolutely helps to encourage yeast to settle out. There's nothing you could tell me to convince me otherwise.

 

[Vale71]

Well this certainly flies in the face of conventional wisdom as well as my 10 years of brewing experience.

I think hundreds of years of scientific reasearch in the field of physics trump conventional wisdom any time, wouldn't you agree?

I mean I'm not a chemical engineer, so I'm not going to argue that carbonating warmer with a higher pressure is faster than carbonating colder with a lower pressure. But If I want my beer carbonated RIGHT NOW I can crank up the pressure and shake my keg and have fully carbonated cold beer in about 1min.

And physics tells you that if you were to perform the same gimmicks at a higher temperature, properly adjusting pressure for temperature, your beer will carbonate even faster.

The advantage of chilling beer to serving temp to carbonate is that you can set your CO2 pressure where you're gonna keep it for serving and get your carbonation exactly right. A unitank is fantastic for this purpose, but a keg is just fine if you're not in too big a hurry.

That may or may not be seen as an advantage, but if your goal is to achieve carbonation faster you still need to increase temperature (and adjust pressure accordingly) and not vice-versa.

The idea that beer clears faster at warmer temps is 100% contrary to my own experience. Again, I'm not a Chem-E, so I'll leave any further discussion to people who know better than I do. But Chilling absolutely helps to encourage yeast to settle out. There's nothing you could tell me to convince me otherwise.

A slow, constant-rate cooling will certainly encourage yeast to flocculate and settle, but so will just letting the yeast finish its work. Once fermentables are exhausted healthy yeast can do nothing but flocculate and once it does Stokes' law tells us that yeast and any other suspended particulate will settle faster if the liquid is warmer.
The worst thing you could do however is to rapidly cool the beer, which is very easy to do at the homebrew scale and not so much at the commercial scale, which will shock the yeast into dormancy and possibly prevent it from properly flocculating. This is however irrelevant if the yeast has already flocculated and must only physically settle. In this case rapidly cooling the beer will have the same effect as saying "abracadabra" and the yeast will still settle more slowly if the beer is cold than if it is warm.

 

[Blazinlow86]

I think hundreds of years of scientific reasearch in the field of physics trump conventional wisdom any time, wouldn't you agree?



And physics tells you that if you were to perform the same gimmicks at a higher temperature, properly adjusting pressure for temperature, your beer will carbonate even faster.



That may or may not be seen as an advantage, but if your goal is to achieve carbonation faster you still need to increase temperature (and adjust pressure accordingly) and not vice-versa.



A slow, constant-rate cooling will certainly encourage yeast to flocculate and settle, but so will just letting the yeast finish its work. Once fermentables are exhausted healthy yeast can do nothing but flocculate and once it does Stokes' law tells us that yeast and any other suspended particulate will settle faster if the liquid is warmer.
The worst thing you could do however is to rapidly cool the beer, which is very easy to do at the homebrew scale and not so much at the commercial scale, which will shock the yeast into dormancy and possibly prevent it from properly flocculating. This is however irrelevant if the yeast has already flocculated and must only physically settle. In this case rapidly cooling the beer will have the same effect as saying "abracadabra" and the yeast will still settle more slowly if the beer is cold than if it is warm.

So back to the question at hand why do you think brewerys cold crash there products near freezing temperatures? Cheers

 

[Vale71]

So back to the question at hand why do you think brewerys cold crash there products near freezing temperatures? Cheers

Which breweries are you talking about? I know of commercial breweries who lager their product but I'd rather not get into detail about lagering. I'm not aware of any brewery cooling their 10-20-50-100 hectoliter tanks within a 24hr period and then letting the beer warm up again after a couple of days, the reason being on the one hand they lack the cooling capability to cool such a large mass in such a short time period and on the other hand the energy costs would be huge and a total waste of money.

P.S. Or maybe you meant inline cooling in the packaging plant, which is done through high-performance heat exchanger(s) right before centrifugation and/or filtration? In that case the brewery wants the beer as cold as possible to prevent foaming and residual O2 pickup during packaging. It certainly has nothing to do with the beer clearing up as that is taken care of by the centrifuge and/or PVP addition and/or filtration.

 

[Blazinlow86]

Which breweries are you talking about? I know of commercial breweries who lager their product but I'd rather not get into detail about lagering. I'm not aware of any brewery cooling their 10-20-50-100 hectoliter tanks within a 24hr period and then letting the beer warm up again after a couple of days, the reason being on the one hand they lack the cooling capability to cool such a large mass in such a short time period and on the other hand the energy costs would be huge and a total waste of money.

P.S. Or maybe you meant inline cooling in the packaging plant, which is done through high-performance heat exchanger(s) right before centrifugation and/or filtration? In that case the brewery wants the beer as cold as possible to prevent foaming and residual O2 pickup during packaging. It certainly has nothing to do with the beer clearing up as that is taken care of by the centrifuge and/or PVP addition and/or filtration.

It would be alot quicker for you to list the **Craft** brewers using 10-100 hectoliter tanks with a centerfuge than the other way around I imagine . Furthermore I think we're getting farther off track here. So back to the question at hand. Any input?

 

[Vale71]

So back to the question at hand why do you think brewerys cold crash there products near freezing temperatures? Cheers

I think you should ask them, I would I know

It would be alot quicker for you to list the **Craft** brewers using 10-100 hectoliter tanks with a centerfuge than the other way around I imagine . Furthermore I think we're getting farther off track here. So back to the question at hand. Any input?

Why don't you list the breweries that use "cold crashing" and who have told you personally that they do it because that way their beer clears faster, all the laws of physics be damned? For all I know there are none and you are just using a meaningless argument to justify your blatantly wrong statements. I've said all I have to say about this topic, those of you who want to keep believing this nonsense can keep doing it and you can also believe in the tooth fairy for all I care.

 

[Blazinlow86]

I think you should ask them, I would I know

Why don't you list the breweries that use "cold crashing" and who have told you personally that they do it because that way their beer clears faster, all the laws of physics be damned? For all I know there are none and you are just using a meaningless argument to justify your blatantly wrong statements. I've said all I have to say about this topic, those of you who want to keep believing this nonsense can keep doing it and you can also believe in the tooth fairy for all I care.

Ive already mentioned why i wont list the brewers in my home town that arent using the process you have described. #1 is there would be close to 200 (and thats not even including the 200+ in my homebrew club alone) that i would have to type out compared to the 10-15 that do use the process you described and i really dont care your the one that brought it up out of the nowhere,#2 is that you most likely would have never heard of them anyway, #3 is all that it would confirm is that your correct that the largest breweries in the world dont cold crash there 100 hectolitre tanks which isnt being debated by anyone, #4 and most importantly it has nothing to do with anything anyone is taking about besides yourself. if the op buys a 100 hectolitre brewery down the road your comments could be relevent. until then cheers .

 

[GnenieGone]

You've heard a lot but I like to get the beer off sediment/yeast/trub etc before going to serving keg. I crash at 55F for 2days. Works fine for me. Heard Russian River does 60F. Just leaving in fermenter for 3 weeks does the same thing anyway. We're just impatient.

 

[Beerwildered]

Wow. This escalated quickly.

 

[Blazinlow86]

Wow. This escalated quickly.

No kidding. Everyone has there opinion but come on. If you don't believe your beer will drop out faster after sitting refrigerated vs unrefrigerated that's your choice. But to expect everyone else to accept that when in first hand experience it doesn't work like that is a bit of a stretch. Cheers

 

[KyleF318is]

Some interesting thoughts on here for sure. If you are fermenting in a corny keg, remove blow off tube and cold crash....does this eliminate O2 suckback? Sorry don’t know the right term. Total rookie at fermenting in a corny but thought this might be a plus? I’m cool being wrong. Haha

 

[Blazinlow86]

Some interesting thoughts on here for sure. If you are fermenting in a corny keg, remove blow off tube and cold crash....does this eliminate O2 suckback? Sorry don’t know the right term. Total rookie at fermenting in a corny but thought this might be a plus? I’m cool being wrong. Haha

Yes. I would suggest keeping co2 on the keg while the temperature is dropping however. Cheers

 

[day_trippr]

I am not sure I got this correctly but is someone actually advocating no-crash clears beer faster than cold-crashing?

Cheers!

 

[Alex4mula]

I put my carboy in freezer at 33-34F for 2-8 days. I also add gelatin at this step for non dark beers. Then I keg and carb in 16-20hrs with diffusion stone. Works great for me.

 

[mongoose33]

Some interesting thoughts on here for sure. If you are fermenting in a corny keg, remove blow off tube and cold crash....does this eliminate O2 suckback? Sorry don’t know the right term. Total rookie at fermenting in a corny but thought this might be a plus? I’m cool being wrong. Haha

Well, if you've sealed up the keg properly, there can't be any suckback unless you've not seated the lid correctly. Otherwise, it's sealed. You will create a partial vacuum unless you add some CO2 to create positive pressure.

 

[CentralCoastBrewer]

As a professional, I will recommend you chill your beer as fast as possible to the lowest reasonable temperature you can after it has passed VDK.

Chris

 

[CentralCoastBrewer]

My glycol system is set to 28F and that is more for safety reasons than anything else as the glycol concentration will let me chill it more. I aim to get my beers at 30 for cold conditioning.

Chris

 

[Blazinlow86]

The main reason people do this stuff is because somebody came up with the idea mostly out of ignorance and everybody started repeating it so that it somehow became true. From there to becoming a fad it doesn't take that long, especially when the Internet comes into play. Just to set a couple of things straight:

1 - Beer carbonates faster the warmer it is. The speed at which beer absorbs CO2 is determined by the diffusion rate of CO2 in the beer. The laws of physics tell us that the rate increase with increasing temperature (more kinetic energy = more speed). Of course, since the solubility of gases decreases with temperature this means that we'll need to set a higher pressure in the headspace to reach the same amount of dissolved CO2 in the beer, but we'll still get there faster the warmer the beer is.
2 - Suspended solids drop faster the warmer the beer is. This is due to the fact that a liquid's density and hence its viscosity decreases with increasing temperature and it's the viscosity that determines how much resistance the droppping particles will encounter. Lower resistance = higher speed. Water has the so-called "anomaly of water" which means that below 4°C its density starts decreasing again. Still at 0°C density is higher than at 20°C so a warm beer will still clear faster than the same beer cooled to near-freezing temp. Chill haze is a totally different issue as it needs first to form and then to become permanent for it to start clearing at all. For that to happen you do need cold temperatures but on the other hand you also need to keep the beer cold for much longer than a couple of days, i.e. you need proper lagering (or cold-conditioning if you will) for chill haze to clear without filtration, if you just "crash" for a couple of days and then transfer the chill haze will still be there.

Cooling beer very fast also had the issue that the yeast will experience a thermal shock and go dormant. This could inhibit, among other things, flocculation and maturation of the beer (VDKs cleanup and all that stuff) which means your beer might take longer to mature or possibly have serious issues like detectable diacetyl.

I know I'm probably fighting windmills here but I'd still like to put that out, make of that what you will. Cheers.

Unless I'm misunderstood his point in this very long reply im thinking vale71 was the only one that disagreed about the benefits of cold crashing. Cheers

 

[CentralCoastBrewer]

The amount of literature on this is staggering if you search the brewing journals. Get your beer as cold as you possibly can without freezing it. That is pretty much canon law in brewing.

Chris

 

[CentralCoastBrewer]

"- Beer carbonates faster the warmer it is" this is utter ********.

Chris

 

[day_trippr]

Seriously, unless someone yaks up a solid reference for this "everything works better when warm" proposition I'm calling shenanigans

Cheers!

 

[CentralCoastBrewer]

Generally, chemically, it is true that things happen faster at warmer temperature. That is just fine and well understood science. What is ALSO well understood science is the relationship between temperature and gas saturation in liquids. High temperature is not your friend in this case and you need excessive pressure to overcome the difficulties.

Chris

 

[balrog]

This

 

[Stand]

The worst part about this thread is that it had potential.

Tone matters.

I am still interested, but seriously wtf.