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These are all very basic brewing rules in the first place.

1- i dont splash when transferring except from BK to fermenter , thats it.
2- i always use O2 absorbing caps and i have never had a faulty cap seal(I use a red baron wing capper since day 1)
3- i dont purge (see #2)
4- I do not keg. I bottle...i store any unrefrigerated beer in the back corner of my basement ,in boxes ,covered. stays about 65*F .
5- my beer doesnt last long enough to worry about freshness. The few that have lasted over a year were just as good (if not better) as the first one opened 2 weeks after bottling.
 
Since you asked, BJCP lists characteristics of oxidized beer as "stale, papery, cardboard" and lists these possible solutions: "Check for oxygen being introduced into beer post-fermentation. Don't splash when racking/bottling. Check caps and/or keg seals for good fit. Purge bottles/kegs with CO2 prior to filling. Store beer cool. Drink beer when fresh."
Stale, paper/cardboard, sherry, etc. are extreme, late stage effects. Very early, though, effects become noticeable, such as diminishing hop aroma, muting of malt flavors, darkened color, and many other subtle changes where beer just doesn't taste as fresh as it could or should. If your beer from the keg or bottle doesn't taste and smell exactly like your last hydrometer sample during fermentation (minus the yeasty chunks,) it's oxidized. Its up to you whether that matters.
 
is there any general guidance for the volume of gas being sucked back when cold crashing?

E.g. if I have a 6.5g carboy and 5.5g of beer, and I cold crash from 68F to 35F, what volume of gas should I expect to suck-back?

if this is pretty constant and predictable, I'd like to create a large enough "gas reservoir" in my blow-off system to prevent both sanitizer and O2 from pulling back into my carboy.

FWIW, I'm thinking of just creating enough of a "gas reservoir" by lengthening my blow-off tube to provide enough volume.


Think outside the balloon.

I bought a couple of undrilled stoppers and carbonation caps, like these:
https://www.morebeer.com/products/carbonation-line-cleaning-ball-lock-cap-stainless.html

I drilled the undrilled stoppers with small holes... so that the carbonation cap barb would be a tight fit, and hold a seal.

After fermenting with the normal stopper/airlock... I sanitized and replaced the stopper with the new stopper and carbonation cap before cold crashing. When the fermenter shrinks due to cold crashing, I pop a ball lock gas connector connected to CO2, and "inflate" the fermenter back to normal size with with my CO2 tank. Presto, no air introduced, and pretty darn simple.

After a time or two... I improved the process a bit by switching out the stoppers earlier. I let fermentation happen with a normal stopper/airlock for a few days... then once I am confident the most vigorous fermentation is over (and krausen isn't getting up into the airlock), I replace the normal stopper/airlock with a stopper with carbonation cap... with a ball lock connector attached to an open ended tube ending dropped into a vessel of sanitizer. Essentially, a 'normal' blowoff-tube setup... but using the stopper/carbonation cap and gas connector. When fermentation is completely over, I just remove the gas connector blowoff tube... (leaving the stopper/carbonation cap on the fermenter) cold crash, let it shrink, and attach a CO2 tank and refill the depleted headspace (and unshrink the fermenter). This method makes it so that the one time I remove the stopper early-mid fermentation... there is still active fermentation occurring, reducing the thought that oxygen will sit in the headspace.

This works great for plastic fermenters, which simply "shrink" due to cold crashing. The stopper has always held a seal, as is apparent by the 'shrunk' fermenter. I've also done similar things with SS fermenters.

If you're cautious... you can just add a burst of CO2 a couple of times as the temperature is dropping, rather than all at once at the end of cold crashing.

And if you don't keg... and don't have a CO2 tank on hand... the above post was unhelpful. (And you should consider kegging!)
 
normal breathing air in a normal environment consists of an avg of 20% oxygen. apparently I dont know what beer ruined by exposure to oxygen tastes like so why dont you enlighten me on signs of that instead of going straight to being a smart @$$ just because I dont belong to your LODO thought process.
Ive been homebrewing for over 4 years and at least a dozen AG brews.
For decades ,brewers have fermented in open vats and I dont think any of those were "ruined" by being exposed to oxygen. In fact, those open fermented beers are probably the best tasting old world styles.

It's apparent that no one is going to talk you in to reevaluating your cold side practices because you're content with what you do and what you get out of it. I've been brewing for 14 years and almost every year of that, I was pretty convinced I had my process locked down and perfect. Every year after that I was proved wrong by experimentation. In the end, bias and being stubborn just slowed me down from achieving better beer. I was always just content with my beers. About two years ago I made several small changes all at the same time. These small changes, on their own, could be written off by a waste of time as it barely improved anything. Put a few of them together and the beer was fantastic. I mean, it was finally beer that I feel like I would pay for and go back for more rather than just some delusional fatherly love. It was also confirmed by a very successful competition run with classic styles, lagers, and the like. I won't get into all the things I did to get there, but the one I felt had the most impact was zero oxygen exposure on the cold side. If this is me being a smart ass, I'll own that.
 
If kegging, why not just transfer to purged keg, then cold crash inside the keg? If you are worried about pulling the trub and yeatst from the bottom of your cold crashed keg, either cut the long dip tube a bit or use one of those fermzilla floaty devices that always pulls from the top. Or just pull from bottom and toss the first glass of beer.

Also in another thread like this someone brought up using a hospital type sterile bladder, the ones they use to collect pee from a catheter which I thought was brilliant. One tube going from carboy into the catheter bladder, then another tube from the bladder into sanitizer filled cup. Kind of use this as an intermediate C02 capture device between your fermentor and the airlock. Great thing about this idea is the catheter already has the in and out valves on it so its great for this purpose.

https://www.healthproductsforyou.co...22V_4xuhdPFrVZr6AnOg8UO2zAL1vhaxoCG4YQAvD_BwE
 
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If kegging, why not just transfer to purged keg, then cold crash inside the keg? If you are worried about pulling the trub and yeatst from the bottom of your cold crashed keg, either cut the long dip tube a bit or use one of those fermzilla floaty devices that always pulls from the top. Or just pull from bottom and toss the first glass of beer.

I think most people want to cold crash in the fermenter because of this homebrewer's myth that it will make the beer clear faster when in reality it will only slow it down. And possibly have a negative impact on maturation to boot...
 
It's apparent that no one is going to talk you in to reevaluating your cold side practices because you're content with what you do and what you get out of it. I've been brewing for 14 years and almost every year of that, I was pretty convinced I had my process locked down and perfect. Every year after that I was proved wrong by experimentation. In the end, bias and being stubborn just slowed me down from achieving better beer. I was always just content with my beers. About two years ago I made several small changes all at the same time. These small changes, on their own, could be written off by a waste of time as it barely improved anything. Put a few of them together and the beer was fantastic. I mean, it was finally beer that I feel like I would pay for and go back for more rather than just some delusional fatherly love. It was also confirmed by a very successful competition run with classic styles, lagers, and the like. I won't get into all the things I did to get there, but the one I felt had the most impact was zero oxygen exposure on the cold side. If this is me being a smart ass, I'll own that.
First of all i didnt make that comment about being a smartass to you.
I would truly like to know what you do for the cold side that allows zero oxygen exposure.
 
You keep saying that but it demonstrably does not match reality. Which is why people keep cold crashing...

So again, why not cold crash in the keg where you can pressurize it and basically no chance of suck back if your stuff is working correctly? Why does the cold crash have to be in the primary?
 
You keep saying that but it demonstrably does not match reality. Which is why people keep cold crashing...
Yes, people are entitled to believe whatever they please. That doesn't make it demostrably true though, for that you need proof and of that there is demonstrably none.
 
So again, why not cold crash in the keg where you can pressurize it and basically no chance of suck back if your stuff is working correctly? Why does the cold crash have to be in the primary?
To keep more stuff out of the keg? Yeast autolysis is a well known scientific fact even though there are of course people claiming that that doesn't matter or that it only matters for commercial operations.
 
Most of the yeast is already left behind in your primary, right? So now you have only the suspended yeast to worry about, so when cold crashing in keg, give it a few days and then just pour it off from the bottom if you are worried about it.

And yeah I heard the same thing. Commercial breweries use huge conical fermentors which by their shape and design focus tons of weight on the yeast which you will never experience as a home brewer with 5 gal batches. I think this is one of those home brew myths that kind of stuck around from the old days.
 
If kegging, why not just transfer to purged keg, then cold crash inside the keg? If you are worried about pulling the trub and yeatst from the bottom of your cold crashed keg, either cut the long dip tube a bit or use one of those fermzilla floaty devices that always pulls from the top. Or just pull from bottom and toss the first glass of beer.

Also in another thread like this someone brought up using a hospital type sterile bladder, the ones they use to collect pee from a catheter which I thought was brilliant. One tube going from carboy into the catheter bladder, then another tube from the bladder into sanitizer filled cup. Kind of use this as an intermediate C02 capture device between your fermentor and the airlock. Great thing about this idea is the catheter already has the in and out valves on it so its great for this purpose.

https://www.healthproductsforyou.co...22V_4xuhdPFrVZr6AnOg8UO2zAL1vhaxoCG4YQAvD_BwE

Except the fact that they typically (almost all of them) have anti backflow valve so the CO2 won't be able to go back into the fermenter.
 
First of all i didnt make that comment about being a smartass to you.
I would truly like to know what you do for the cold side that allows zero oxygen exposure.

I knew you weren't replying specifically to me. I was just presuming that challenges to your process were taken that way. Sorry.

I do cold crash with a CO2 filled bladder on my fermenters that cannot be trusted with a CO2 tank/reg left connected. After about 2-3 days of being cold, all the moderate sized particulate is settled out and I can keg it without clogging poppets.

I fill my keg to the top with water, add 1oz of starsan, cap and then roll it around to mix. I use a 3/8" hose with a racking cane on one end and a black ball lock QD on the other. I attach that to the keg output and then connect CO2 to push all the starsan into a bucket. The racking can then goes into the lid of my fermenter. Usually this is a Fermonster with a modified solid lid that has a grommet to seal around the racking cane and also a gas ball lock post to be able to add CO2. It can also be a PET or glass carboy with a carboy cap. Note: I do reuse the starsan for about another 1-2 weeks, but just for sanitizing fermenters and the like. If it sits around for too long, it will pickup oxygen that partially negates its use for this exact purpose.

I move the CO2 supply to the fermenter, pull the vent on the keg, and increase the regulator pressure to about 1.5 to 2psi to get the beer to flow up the racking cane and into the fermenter.

That's pretty much it. This process doesn't allow even a tiny bit of oxygen in and even sensitive NEIPA stays pale golden for months. I have a 4 month old NEIPA in a keg and most people can't peg it as aging out unless they've had it earlier.

The other thing on the cold side that has most recently made a huge difference is switching all my beer and gas lines out for the EVAbarrier from the PVC stuff. PVC tubing lets a remarkable amount of O2 into the kegs and I had no idea for a long time.
 
I knew you weren't replying specifically to me. I was just presuming that challenges to your process were taken that way. Sorry.

I do cold crash with a CO2 filled bladder on my fermenters that cannot be trusted with a CO2 tank/reg left connected. After about 2-3 days of being cold, all the moderate sized particulate is settled out and I can keg it without clogging poppets.

I fill my keg to the top with water, add 1oz of starsan, cap and then roll it around to mix. I use a 3/8" hose with a racking cane on one end and a black ball lock QD on the other. I attach that to the keg output and then connect CO2 to push all the starsan into a bucket. The racking can then goes into the lid of my fermenter. Usually this is a Fermonster with a modified solid lid that has a grommet to seal around the racking cane and also a gas ball lock post to be able to add CO2. It can also be a PET or glass carboy with a carboy cap. Note: I do reuse the starsan for about another 1-2 weeks, but just for sanitizing fermenters and the like. If it sits around for too long, it will pickup oxygen that partially negates its use for this exact purpose.

I move the CO2 supply to the fermenter, pull the vent on the keg, and increase the regulator pressure to about 1.5 to 2psi to get the beer to flow up the racking cane and into the fermenter.

That's pretty much it. This process doesn't allow even a tiny bit of oxygen in and even sensitive NEIPA stays pale golden for months. I have a 4 month old NEIPA in a keg and most people can't peg it as aging out unless they've had it earlier.

The other thing on the cold side that has most recently made a huge difference is switching all my beer and gas lines out for the EVAbarrier from the PVC stuff. PVC tubing lets a remarkable amount of O2 into the kegs and I had no idea for a long time.
I bottle so none of that applies to me. Thanks for your input though
 
Yes, people are entitled to believe whatever they please. That doesn't make it demostrably true though, for that you need proof and of that there is demonstrably none.

Prove it doesn't work.
I'm guessing you've never cold-crashed anything...

Cheers!
 
Prove it doesn't work.

It appears you have religion mixed up with science again. You're the one claiming that particulate settles faster at lower temperature despite the laws of physics as we know them saying exactly the opposite. The onus of proof is on you. By saying "That's what I believe. Try and prove me wrong." you're just clearly showing the religious and unscientific nature of your statement.

I'm guessing you've never cold-crashed anything...
If by "cold-crashed" you mean played around with temperature control without the slightest idea of what that does to your beer then yes, that's a charge I plead guilty to.
 
Bringing Scope's fluid dynamics into this again?

If you turn off the CO2 evolution, everything sinks.
It's that simple...

Cheers!
 
If you turn off the CO2 evolution, everything sinks.
It's that simple...

Cheers!
If you actually wait for fermentation to finish CO2 evolution (and thermal convection as well) stops by itself (signalled since the dawn of brewing by the Kräusen falling), it's that simple... To get CO2 to release beyond that point you'd have to shake the fermenter and that's certainly going to delay sedimentation quite radically by itself. ;) There is really no valid reason to prematurely shock the yeast into dormancy and possibly compromise fermentation/maturation, just as there is no need to keep inventing stuff to justify this cold-crashing misconception.
 
Do you ever brew a heavily dry-hopped beer?
Are you familiar with "hop creep"? And how long it can continue?
That's why I cold-crash...

Cheers!
 
So, I guess if I want to extend my blowoff hose to be a CO2 reservoir, I'm going to need a REALLY LONG hose... [emoji1787][emoji1787][emoji1787]

What if, instead of using a long blow-off hose as a CO2 reservoir, you just add something with a larger opening and volume to the end of the blow-off tube. Imagine a large funnel (or similar vessel) inverted so that the large opening is face down and the blow-off hose is connected to the narrow end. The funnel is then submerged into the blow-off reservoir. During fermentation the hose and funnel are filled with CO2. During the cold crash when suck back happens, it seems it would take a larger negative pressure to first pull enough liquid to fill the funnel before it even gets to the hose. I do not have any math to back this up - just thinking it through. What say ye?
 
Gas expands at around 16 times as much as water due to temperature changes. I'm not sure if I'm right but based on calculators on the web, 5 gallons of water will contract about a half cup going from 70 to 32. I always use a secondary using a 5 gallon carboy. I top it off with water so that there is very little air left. This winter is the first time I cold crashed. The first few times I cold crashed I measured how much the water/beer line lowered and it was insignificant. I top off the beer with water so that it reduces any air/oxygen in the secondary and it also makes cleaning the carboy easier because all the krausen is on the neck where it's easy to clean.
 
I always use a secondary using a 5 gallon carboy.... I top off the beer with water so that it reduces any air/oxygen in the secondary
If you're concerned about oxygen, it would be best to avoid using a secondary vessel altogether.
 
Actually I'm not concerned about it. For me there will be much more exposure during bottling than transferring to a secondary. If I ever get to the point where I keg then things may change. Once I transfer to a secondary it normally becomes clear within 24 hours. This winter I experimented with cold crashing, I'm not sure if it did anything for me. My point is that gas versus liquid has about a 16x expansion factor.
 
Gas expands at around 16 times as much as water due to temperature changes. I'm not sure if I'm right but based on calculators on the web, 5 gallons of water will contract about a half cup going from 70 to 32.

Maybe that is what the math shows but in practice I have seen a lot more "suck back" than that. The first and last time I got burnt with this, I dropped the temp from 65 to 38 (27 degrees) and had about 2 1/2 to 3 cups of StarSan sucked back up a 1/2" ID blow off tube with about an 18" elevation change in a 5 gallon batch. I couldn't believe it when my sanitizer container was completely empty. Now I only drop the temperature in a sealed keg.
 
Maybe that is what the math shows but in practice I have seen a lot more "suck back" than that. The first and last time I got burnt with this, I dropped the temp from 65 to 38 (27 degrees) and had about 2 1/2 to 3 cups of StarSan sucked back up a 1/2" ID blow off tube with about an 18" elevation change in a 5 gallon batch. I couldn't believe it when my sanitizer container was completely empty. Now I only drop the temperature in a sealed keg.
This was addressed earlier in the thread. The larger volume change (after some time) with cold crashing is due to CO2 being absorbed by the colder beer from the head space (which should be close to 100% CO2 when you start cold crashing.)

Brew on :mug:
 
If you had 2 to 3 cups of StarSan sucked into your fermentor then you didn't have less than a cup of c02/air in your fermentor that you were cold crashing.
 
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Gas expands at around 16 times as much as water due to temperature changes. I'm not sure if I'm right but based on calculators on the web, 5 gallons of water will contract about a half cup going from 70 to 32. I always use a secondary using a 5 gallon carboy. I top it off with water so that there is very little air left. This winter is the first time I cold crashed. The first few times I cold crashed I measured how much the water/beer line lowered and it was insignificant. I top off the beer with water so that it reduces any air/oxygen in the secondary and it also makes cleaning the carboy easier because all the krausen is on the neck where it's easy to clean.
Unless you somehow degas that top-up water you've just dosed your beer with a more or less massive dose of dissolved O2 so anything you do afterwards is more or less irrelevant.
 
My point is that gas versus liquid has about a 16x expansion factor.
I'm not sure how you arrived at that figure. My calculations show a 42x difference in expansion from 0C to 20C.

It is possible to bottle beer without significantly oxidizing it.
 
Unless you somehow degas that top-up water you've just dosed your beer with a more or less massive dose of dissolved O2 so anything you do afterwards is more or less irrelevant.
I boil the water before adding it, it's never more than a quart anyway since it's in the secondary.
 
I'm not sure how you arrived at that figure. My calculations show a 42x difference in expansion from 0C to 20C.

It is possible to bottle beer without significantly oxidizing it.
Water has an expansion coefficient of 210 × 10 6 and gases have 3400 × 10 6
https://courses.lumenlearning.com/physics/chapter/13-2-thermal-expansion-of-solids-and-liquids/https://www.omnicalculator.com/physics/thermal-expansion
About bottling I was referring to the exposure to oxygen while in the bottling bucket, I'm not sure how significant that would be.
 
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I boil the water before adding it, it's never more than a quart anyway since it's in the secondary.
It makes no difference if you let it cool while exposed to atmospheric oxygen. Between the open transfer and the top-up water you're adding way more oxygen than any suckback would introduce into the beer and that's even before packaging is taken into consideration.
 
The volume of gas will decrease proportionally to the temperature in degrees Kelvin.

68F is 293
35F is 275
With your numbers, the volume of gas will contract by about 6.1%, so you need about 0.065 gallons of reserve CO2 to prevent suckback. :)

If you are truly concerned about oxygen, spunding is the way to go, definitely no cold crash.

Cheers

You can both spund *and* cold crash without oxygen exposure if you have the correct fermentation vessel... that being a pressure rated vessel of some sort, not a plastic/glass carboy. You can cold crash while minimizing oxygen exposure with a reservoir bag of CO2.
 
So again, why not cold crash in the keg where you can pressurize it and basically no chance of suck back if your stuff is working correctly? Why does the cold crash have to be in the primary?

Because I like clear beer in the keg so I can move it around without stirring it back up? It's also more storage friendly without extra yeast/trub in there? It makes cleaning the kegs a lot easier when there isn't a bunch of mud in the bottom?

Need some more reasons?
 
It's apparent that no one is going to talk you in to reevaluating your cold side practices because you're content with what you do and what you get out of it. I've been brewing for 14 years and almost every year of that, I was pretty convinced I had my process locked down and perfect. Every year after that I was proved wrong by experimentation. In the end, bias and being stubborn just slowed me down from achieving better beer. I was always just content with my beers. About two years ago I made several small changes all at the same time. These small changes, on their own, could be written off by a waste of time as it barely improved anything. Put a few of them together and the beer was fantastic. I mean, it was finally beer that I feel like I would pay for and go back for more rather than just some delusional fatherly love. It was also confirmed by a very successful competition run with classic styles, lagers, and the like. I won't get into all the things I did to get there, but the one I felt had the most impact was zero oxygen exposure on the cold side. If this is me being a smart ass, I'll own that.
You stubborn...no way. I also couldn’t agree more. Sometimes the smallest things have the largest impact.
 
It makes no difference if you let it cool while exposed to atmospheric oxygen. Between the open transfer and the top-up water you're adding way more oxygen than any suckback would introduce into the beer and that's even before packaging is taken into consideration.
How can 2 cups of water have more dissolved oxygen than 2 cups of air? I don't let it cool anyway. I transfer to the secondary after all chances of blow-off are gone and leave it there for about 2 weeks before bottling.
 
These small changes, on their own, could be written off by a waste of time as it barely improved anything. Put a few of them together and the beer was fantastic.

This is the reason it drives me nuts when people say things like "X doesn't make any difference. I don't do X and my beers are great." Stacked tolerances can add up to mediocre beer.
 
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