Cold crashing question?

[jfk69]

I have yet to cold crash my beers, preferring to give them more time in the fermenter to clear. However, I have a club beer which I need to dry hop with pellets. Normally, when I do this I just rack to secondary and put the hops in a sack, however, I'm a wee bit short on pails and carboys at the moment lol.:rockin: So I'm going to dry hop the primary and figured I'd cold crash it for a couple days to help get the hop junk and yeast settled out.

My question is, after cold crashing, do you bottle cold, or let it warm up for 12-18 hours to room temperature before doing it?

 

[narl79]

Ive done both but only bottled cold one time so far. It was a pale and didnt notice anything off so im doing it again with a brown tomorrow just to see. I hope more experienced people wil jump in on this.

 

[fearwig]

It works pretty well. Try some gelatin in the cold crash to keep the hop gunk in place and help even more with clearing.

I've never had a problem bottling cold, I seem to remember someone saying not to, but I can't remember why. The beer was fine.

 

[BigFloyd]

Bottle cold. I pull my primary bucket out of a 35*F freezer and go straight to the bottling bucket or keg. I do give the priming sugar a very gentle stir with a sanitized spoon to evenly distribute it. If using a calculator, enter the highest temp the beer saw during fermentation.

If you can, a few extra days of crashing will help. I normally let it go 5-7 days.

 

[d3track]

Bottle cold, I have a theory that the temp change could kick particles back up into suspension

 

[BigFloyd]

Bottle cold, I have a theory that the temp change could kick particles back up into suspension

It's not so much that as the warm up causes the yeast trub, which became nice and firm from the cold crash, to become less firm. That allows it to be sucked up into the siphon more easily.

 

[HoppyT]

You can bottle while still cold OR wait for it to come back to room temp. I would say bottling while still cold is preferable because it allows you to siphon while the trub is out of suspension due to the above reasons.

However, be careful with your priming sugar calculation as this is sensitive to temperature. The colder you bottle, the less priming sugar you'll need. Refer to Palmer's book or http://www.tastybrew.com/calculators/priming.html

 

[fearwig]

As stated above I believe you should go by the highest temperature the beer reached (once active fermentation was complete), because your beer will offgas dissolved CO2 as it warms but it won't reclaim it in any real quantity when it is cooled.

 

[BigFloyd]

As stated above I believe you should go by the highest temperature the beer reached (once active fermentation was complete), because your beer will offgas dissolved CO2 as it warms but it won't reclaim it in any real quantity when it is cooled.

Yep. That's a good explanation for the reason to use the higher temp. I've had consistently good results this way.

 

[divrguy]

I have yet to cold crash my beers, preferring to give them more time in the fermenter to clear. However, I have a club beer which I need to dry hop with pellets. Normally, when I do this I just rack to secondary and put the hops in a sack, however, I'm a wee bit short on pails and carboys at the moment lol.:rockin: So I'm going to dry hop the primary and figured I'd cold crash it for a couple days to help get the hop junk and yeast settled out.



My question is, after cold crashing, do you bottle cold, or let it warm up for 12-18 hours to room temperature before doing it?

I saw the part where you say you're short on buckets but do you have a bottling bucket? I ferment and dry hop in primary. Then, depending on the beer, dry hop as well in primary and then cold crash in primary. But, I will always transfer to a bottling bucket (cold) calculating priming sugar using the fermentation temp (like 67) and it works great!


Cheers!

 

[Calichusetts]

My carboy goes straight from 38 degree fridge to counter for bottling. Granted, I do let it settle out for a few hours but that is only because of the stirrup from moving it. I could care less what the temp is. It will carb if you set it at room temp for a few weeks.

 

[kombat]

I have a theory that the temp change could kick particles back up into suspension

It's not so much that as the warm up causes the yeast trub, which became nice and firm from the cold crash, to become less firm. That allows it to be sucked up into the siphon more easily.

That's probably a factor, but in my experience, I agree with d3track. I've noticed that if I allow a cold-crashed batch of beer to warm up, little CO2 bubbles will actually "explode" out of the yeast cake, launching yeast sediment and trub back up into suspension.

I believe this is because as you cold crash the beer, the yeast are still (albeit very slowly) munching on sugars and producing CO2. Since it takes several hours for the beer to chill enough to put the yeast to sleep, they work slower and slower as the beer cools, producing CO2 which stays in solution (because the beer is getting cold).

Think of it this way. Your beer is sitting at 68° F. You move it into the fridge, which is at 34° F. A couple of hours later, the beer temperature has dropped to, say, 60° F. The yeast are getting sluggish, but still doing a small amount of fermenting, and producing CO2. Some of it bubbles out of solution, but however much of it could stay dissolved at 60° F does just that - it stays in solution (since the beer is only getting colder and colder, and thus able to hold more and more CO2).

At some point, the beer gets cold enough that the yeast just stop completely. But during the cooling, they've added some CO2 into solution in the beer. A very small amount, but a non-zero amount nonetheless. Some of it was added when the beer was colder than 60° F, and stayed in solution.

Now, you warm the beer back up. Once the beer warms above, say, 60° F, any CO2 that was added into solution by the (sluggish) yeast when the beer was cooling past 60° F is no longer soluable, and comes out of solution. It does this at "nucleation" sites, or particles onto which it can form. The best candidates for this are, you guessed it, the yeast and trub cells at the bottom of the fermenter. So you get little geysers of CO2 bubbles popping up out of your yeast cake, spraying particulates back up into the beer you worked so hard to clear.

The bottom line is, once you've cold-crashed a beer (with or without gelatin) to clarify it, then to preserve that clarity, you MUST rack it to another vessel (either another fermenter or a bottling bucket) before you allow it to warm back up. Otherwise, it'll just get murky again. Probably not as bad as it was before, but why let it muddy up at all? You've made it clear, so keep it that way.

 

[Calichusetts]

That's probably a factor, but in my experience, I agree with d3track. I've noticed that if I allow a cold-crashed batch of beer to warm up, little CO2 bubbles will actually "explode" out of the yeast cake, launching yeast sediment and trub back up into suspension.

I believe this is because as you cold crash the beer, the yeast are still (albeit very slowly) munching on sugars and producing CO2. Since it takes several hours for the beer to chill enough to put the yeast to sleep, they work slower and slower as the beer cools, producing CO2 which stays in solution (because the beer is getting cold).

Think of it this way. Your beer is sitting at 68° F. You move it into the fridge, which is at 34° F. A couple of hours later, the beer temperature has dropped to, say, 60° F. The yeast are getting sluggish, but still doing a small amount of fermenting, and producing CO2. Some of it bubbles out of solution, but however much of it could stay dissolved at 60° F does just that - it stays in solution (since the beer is only getting colder and colder, and thus able to hold more and more CO2).

At some point, the beer gets cold enough that the yeast just stop completely. But during the cooling, they've added some CO2 into solution in the beer. A very small amount, but a non-zero amount nonetheless. Some of it was added when the beer was colder than 60° F, and stayed in solution.

Now, you warm the beer back up. Once the beer warms above, say, 60° F, any CO2 that was added into solution by the (sluggish) yeast when the beer was cooling past 60° F is no longer soluable, and comes out of solution. It does this at "nucleation" sites, or particles onto which it can form. The best candidates for this are, you guessed it, the yeast and trub cells at the bottom of the fermenter. So you get little geysers of CO2 bubbles popping up out of your yeast cake, spraying particulates back up into the beer you worked so hard to clear.

The bottom line is, once you've cold-crashed a beer (with or without gelatin) to clarify it, then to preserve that clarity, you MUST rack it to another vessel (either another fermenter or a bottling bucket) before you allow it to warm back up. Otherwise, it'll just get murky again. Probably not as bad as it was before, but why let it muddy up at all? You've made it clear, so keep it that way.

You are saying a lot of things here...first of all, the yeast should be done fermenting when you crash. You are correct, temperature affects how much co2 is in your solution, but this is the science of temp, nothing to do with the yeast. I've not had my beer get cloudy once it warms up again in my experience. But you might be right about the nucleation site. Though I figure its probably going to be on the hop particles as well

 

[kombat]

the yeast should be done fermenting when you crash.

Of course. But yeast are not a binary "on/off" switch. They're living things. If they're not doing anyting at all, then frankly, they're dying. As their food supply is exhausted, they go dormant, but that doesn't mean every last single atom of sugars they could ferment has been completely exhausted - just that they've been reduced to trace amounts. In the absence of their preferred food (and faced with starvation and death as the alternative), the yeast will ever so slowly work on the longer-chained sugars. This process is too slow to meaningfully affect hydrometer readings just a few days apart, but my point was merely that they're still producing at least a minute amount of CO2, even after the beer has reached F.G.

If you fermented a beer down to 1.012 after 3 weeks, then just left it untouched for 6 months, do you think the gravity would still be 1.012? Do you think it wouldn't have budged at all?

I've not had my beer get cloudy once it warms up again in my experience.

I've seen this pretty much every brew day. The first thing I do on brew day is remove a Mason jar of reclaimed yeast from the fridge to allow the yeast to warm up over the next 4 hours while I'm brewing. When the jar comes out of the fridge, it's crystal clear (because it's been in there for a few weeks) with a clear pack of yeast in the bottom third/quarter.

If I check the jar periodically as it warms up, I can literally see the occassional CO2 bubble "burst" up out of the yeast bed, launching sediment up into solution.

When I come back at the end of the brew day, the yeast has warmed up, and the (formerly clear) spent wort above the yeast cake is noticeably hazier. Where did that CO2 come from if the yeast was completely done when I claimed it from the last batch it fermented?

 

[Calichusetts]

http://byo.com/recipes-tag/item/437-carbonation-homebrew-science

Its dissolved in the beer, nothing to do with the yeast. There may be some in the bed, but thats because there is beer at the bed. Its all about temp.

And I bottle my beer from cold crashing. My hydrometer is clearing as it warms, not getting cloudy. No idea why that happens in your case.

Of course there is some sugar, but this is negligible at best.

 

[kombat]

Its dissolved in the beer, nothing to do with the yeast.

Except that the yeast are the ones that put it in the beer.

There may be some in the bed, but thats because there is beer at the bed. Its all about temp.

Right. That's what I said. CO2 that was put into the beer (by the yeast) as it was cooling stayed in solution. Now that the beer is warming back up, the CO2 can't stay dissolved, so it comes out of solution.

You ferment your beer at 65°. However much CO2 can be dissolved in your beer at that temperature remains in solution. The rest offgasses out through your airlock or blowoff tube. You warm the beer up to 68° at the end of fermentation. CO2 that could stay dissolved at 65° no longer can, so it bubbles out. Moreover, your yeast get a little more active (because they're warmer) and make more CO2. Then they basically finish, and your beer stops venting CO2. You chill it. You warm it back up. Why would CO2 that happily stayed dissolved at 68° before you cold-crashed it suddenly need to come out of solution when you warm it back up to 68° after you've chilled it?

Because the yeast were still making a (miniscule) amount of CO2 as you were cold-crashing your beer, but it stayed in solution, because the beer temperature was dropping and could support more dissolved CO2.

Of course there is some sugar, but this is negligible at best.

Sure. I never said the beer will foam like a champagne bottle at the finish line of the Indy 500. It only takes a tiny amount of CO2 to come out of solution to cause those "geysers" popping up out of the yeast cake.

 

[Calichusetts]

@Kombat
I have no idea what is going on here. I think we are just misunderstanding each other and thread hijacking. Of course the yeast made the co2. He has his answer so I think we are good

 

[chainlife]

Not only does water at lower temps hold more gas, but also cannot hold as many dissolved solids in suspension, so even if particles kick back up, there is only so much the solution can dissolve and hold onto which is temp dependant


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