I pressurize the fermenter with 2-4 psi of CO2 to prevent Oxygen ingress during cold crash. I leave it on the gas until its down to temp otherwise 4 psi is insufficient and a vacuum will be created. Boyle's Law.
Clarity from brewing technique
- Thread starter Josh Hughes
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I have tried Gelatine and proprietary two-part preparations with varying degrees of success. There is a bit of a faf using them and I am lazy so I have tended to avoid using them for every batch. I do get consistently clear beer just by using Whirfloc tablet @10 minutes before switch off and letting the wort settle before decanting into the FV. I let the fermented beer settle in the FV before bottling after a cold crash and then letting the bottled result slumber in the garage. Sometimes there is a small bit of residue at the bottom of the bottle but I just pour carefully as a result.
It doesn't bother me that I can't get a TOTALY clear bottle - as they do commercially - as I can't afford the filter they use to achieve it.
Drink it and be damned! hic.
It doesn't bother me that I can't get a TOTALY clear bottle - as they do commercially - as I can't afford the filter they use to achieve it.
Drink it and be damned! hic.
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Is that dependent on temperature drop or headspace to beer ratio?
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It's like you knew it was @AHarper 's birthday, but with the time zones and all, you got the days mixed up
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That’s why I posted that picture. If he were retiring or something like that, I would posted a picture with the appropriate balloon for the occasion.It's like you knew it was @AHarper 's birthday, but with the time zones and all, you got the days mixed up
View attachment 14668
Mostly temperature, but volume has some effect.
My error, not Boyle's Law, I should have referenced the "Ideal Gas law", PV = nRT, where P is pressure, V is volume, n is the amount of gas (actual number of gas molecules), R is a constant and T is temperature. So as temperature drops in an enclosed space (V is constant = headspace) P must decrease... and vice-versa.
By keeping a bit of pressure in the fermenter (to add gas molecules as temperature drops), I am increasing 'n' as T drops to maintain a constant P with the gas of my choice, CO2 in this case. A balloon will do the same thing, but does it have enough 'n' to compensate for the temperature drop? Yes if the headspace is small enough. The ratio of headspace to beer is not completely relevant (the beer does contract very slightly, increasing V, but probably not enough to matter) but the volume of headspace determines how much gas is in there.
Bottom line: Cold crash to clarify beer. Some O2 might get sucked back in because of the temperature drop. One can force a little CO2 in there instead of allowing O2 from the atmosphere, there are several methods.
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So the smaller the volume of head space the lower the amount of gas molecules needed to prevent a vacuum. What about dissolved CO2 in solution? Does a small vacuum draw out the CO2 from solution, thus prevent the vacuum from becoming to great? Or is there enough CO2 coming out of solution to prevent a vacuum all together?
I find very this interesting. There are a lot of moving parts to this simple idea of cooling a beer and avoiding a vacuum/ oxygen ingress. I can see headspace plays a big role in it. I have since given up on the balloon idea. It wasn’t perfect, but it was better than nothing. I now spund almost every beer, including ales. I pretty much eliminated all serious chances of ingress. Thanks for bringing it up, I learned something today!
Dunno. There's not much dissolved in the beer at the end of fermentation, but it certainly would contribute. In finished / carbonated beer it is a different story of course.
A vacuum will draw any dissolved gases out of the liquid, and if the vacuum gets high enough at the right temperature, the liquid will start to vaporize into a gas...but I don't think we even come close to that being a significant thing.
For those who cannot spund or otherwise add pressure during cold crash, a source of CO2 of any kind can be used to make up the difference due to the cold. Some run their blowoff tube into the "out" of a corny keg, with the "in" vented to atmosphere. The CO2 from regular fermentation fills the keg (it is heavier than air) and, during cold crash, is introduced back to the fermenter during cold crash.
Or, as I have done many times, just ignore the air going into the fermenter and be happy!
My way of partially paying you back for that awesome pale ale recipe sir.
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Brew on, my good man! Brew on!
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Very kind of you HVM. I retired 9 years ago but I appreciate the thought. I am going to use your method on another recipe and see how it works out. I have lots of hops to use so it may work out useful.
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Some Whitbread IPA.
I post this here to emphasize how important the yeast is to clear beer. This beer was fermented with WY 1469, West Yorkshire. From Wyeast: “Reliably flocculent, it produces bright beer without filtration.” I added 1/2 tablet of whirlfloc to the boil. No finings or cold crashing. It’s not the clearest beer ever, but whatever clarity it has is all thanks to the yeast, not the brewer.
I post this here to emphasize how important the yeast is to clear beer. This beer was fermented with WY 1469, West Yorkshire. From Wyeast: “Reliably flocculent, it produces bright beer without filtration.” I added 1/2 tablet of whirlfloc to the boil. No finings or cold crashing. It’s not the clearest beer ever, but whatever clarity it has is all thanks to the yeast, not the brewer.
Nice!
Bitter i kegged earlier. Pub floc really well. Last few have been pretty clear. I guess 34/70 needs more time to clear? Technique wise I didn’t do anything different
34/70 usually drops pretty clear I find bit of Geletin and two weeks in the keg it'll be pretty brite
recirculating mash and you can watch it clear, after that whirfloc in kettle, then cold crash after fermentation.
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^^^^^^^^^^^^^^^^^
One thing I do that I don't think was mentioned yet is that I skim the hot break proteins from the top of the wort as it's coming to a boil. I think this has some controversy around it tho, some people swear it kills head retention. I'm sure there are other supposed side effects that I'm blanking on at the moment.
As the "egg drop soup" proteins rise up, I use my ladle to make a small vortex and then very slowly and gently skim off just the foam from the top of the liquid. I used to take it all out, but now I stop once it's at full boil and I know it won't boil over.
As the "egg drop soup" proteins rise up, I use my ladle to make a small vortex and then very slowly and gently skim off just the foam from the top of the liquid. I used to take it all out, but now I stop once it's at full boil and I know it won't boil over.
