Cold Crashing / Mylar Balloon

[Tobor_8thMan]

That is correct. I see some CO2 escaping from the spunding valve for a few days into lagering but I definitely don't see any in ales once they're cooled to below 10°C or so.

It also depends on how long you wait to drop temperature. If you wait several weeks there won't be any fermentables left so lager or ale it won't matter as the yeast will have nothing to ferment in either case.

OK, then why do we worry about an airlock? If cold crashing simply use a solid stopper to plug the airlock hole. Or, am I missing something?

 

[Vale71]

Because if you don't spund the amount of residual CO2 produced (if any) will never be enough to compensate for the pressure drop you'll get from the CO2 in the headspace being absorbed into the colder beer.
Since I spund I already have up to 2 bar pressure in the fermenter. When cooled this will drop to about 1.3 bar which is still quite a lot of positive pressure. If you start at atmospheric pressure and seal the fermenter you'll end up with quite a strong vacuum. Either the stopper will be pulled in, which is not so bad, or your fermenter will implode, which is very bad.

 

[Tobor_8thMan]

I was also thinking of a spunding valve. However, what will make the CO2? Yeast continuing to ferment. If the yeast are dead/dormant how are we getting additional CO2?

 

[CodeSection]

Exactly. Get the thickest wall available for your ID.
It doesn't appear to be food grade but that's irrelevant since you won't be transfering either beer or wort through it.
BTW with your kind of setup you're really missing out on a lot of advantages not spunding and not doing closed transfers under pressure, but that decision if yours to make obviously.

Actually, I was looking for something on both the hot and cold side. I will keep looking.

I know very little about spunding other than reading a few articles on it. At one time I was looking at https://www.morebeer.com/products/blichmann-spunding-valve-tc.html. What is difficult to wrap my head around is using something like the BrauKaiser calculator. Then estimating timing and trying to achieve the desired CO2. Again, I know very little of the process.

Even if I learned to effectively spund and perform a closed pressure transfer, I would need a counter pressure bottle filler since I bottle everything. If you recall my other thread, https://www.homebrewtalk.com/forum/threads/closed-system-bottling.670427/#post-8683836, I was concerned if using a closed system bottling method was worth it and if the benefits were too small as compared with the cost of additional equipment and possible extra time involved in bottling.

While I want to refine my processes, I just don't want to significantly extend my bottling time as compared to what I am performing currently. I'm still thinking through this and appreciate your advice.

 

[Vale71]

My apologies to all. I was comparing the permeability of an equivalent PTFE hose and the numbers simply did non match. Turns out I effed up the conversion to mass units by a factor of 100! Oh well, at least I did not crash a multi-million dollar probe on Mars' or any other planet's surface or give my wrong calcs to Stephen Hawking... The results I got are more in line with what you'd actually get from using silicone hose.

I fixed the mistake, the correct daily rate is now about 50mg of O2 per day and not 5g. It's still dangerously high cold side but it's not so bad hot side, even though the actual value hot side will be higher as the manufacturer tested at 23°C and gas diffusion speeds up as temperature increases.

I wouldn't be so afraid of spunding. You generally don't have to get up at 03:00AM to close the valve as fermentation does not proceed so fast. With experience you'll learn to eyeball it and when in doubt it really won't hurt the beer if you spund a little sooner as the spunding valve will release all the excess CO2.
Unfortunately you're right about counter pressure filling, it is time consuming, which is why I now mostly keg my beer and only fill up bottles when I have to take the beer with me to some event, but the increase in quality is worth it IMHO.