Can I ferment completely closed in corny keg under pressure?

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Second the comment about putting the blowoff tube on the gas post unless you want to spray beer all over. What works for me after fermenting several batches in cornies is to use a hop spider during the boil to cut way down on hop debris (relief valves and gas posts can and do easily clog), and shoot for 4.5 gallons into the fermenter with a 1.5 liter starter. Remove the gas tube and poppet from the gas side, shove a tube right over the post and into a blowoff growler. I leave it in there for a week or until active fermentation stops, then I put the poppet/gas tube back in, and throw on a disconnect with the tube in another blowoff jar for minor venting. I had a lot of growing pains and a lot of big messses during the first few, since following this procedure things have gone pretty smoothly.
 
I don't know that this would have been as dangerous as everyone else thinks. If yeast tends to die around 20 psi, and the keg can handle up to 100+ psi, then I suspect you would have just had a highly carbonated wort/beer that was only slightly fermented.

Actually, I bet that as you approach 20 psi, you would begin selecting for yeast that can handle higher pressure, and the population would rapidly decline to near zero (but not quite zero), and those few remaining cells would keep fermenting, with the weakest dying off and the strongest surviving and dividing. If you could then somehow release the pressure without creating a horrible mess, and then step up the surviving yeast, you could repeat the process a few times with successive generations. Sounds like an interesting experiment to me.
 
unless of course you removed the pick up tube from the out post when installing the blow off then it wont matter.

I pulled the liquid out tube from the keg when setting mine up. Just used two gas tubes (one on each post) to make sure it sealed fully. I'm about to get a couple more corny kegs, so I'll have to decide what I'll do with those. Most likely, I'll pull the liquid out tube and install the airlock onto that post. I'll also get enough tubing in case I need to make a blow-off setup for the brew.
 
I just checked the inside of the keg and it seems fermentation is under way though not much beer has been pushed out of the blowoff on the "out" post. Since the lid is not tightly sealed I suspect excess co2 is venting that way preventing any beer getting lost through the blow-off.
 
Good to hear... Just out of curiosity, what ID tubing did you use for the post?

I've decided to pass on the other corny kegs, but I do plan on using the Sanke kegs I have on hand very soon... Luckily, the large universal bung fits those perfectly... :D Just need to get a few more (I have one of the orange caps to use on one of them) and I'll be in business. :rockin:

Can't wait to brew the next batch.
 
Good to hear... Just out of curiosity, what ID tubing did you use for the post?

I've decided to pass on the other corny kegs, but I do plan on using the Sanke kegs I have on hand very soon... Luckily, the large universal bung fits those perfectly... :D Just need to get a few more (I have one of the orange caps to use on one of them) and I'll be in business. :rockin:

Can't wait to brew the next batch.


I'm not sure. 3/16th? It's not ultra snug on the keg quick disconnect so I used a steel clamp.
 
Maybe 3/8"? I'll be checking mine once the brew that's in it is done... Although with the lid setup on mine, as it is, there's not much point in changing it...
 
Yeah, sounds dangerous to me. Consider that you can carb a keg completely with about 3 oz of corn sugar. So you want to throw something in with 10+ pounds of grain and not let off the pressure?

Sounds extremely dangerous and I wouldn't do it. You would be lucky if the Orings failed. You could go to look at the keg and have a poppet or pressure relief valve fly out with the force of a bullet. If you want to ferment in a closed keg, let the pressure out regularly or better yet, invest in a pressure relief valve where you can set a specific psi.

I think it was Budweiser that had a relief valve stick on one of their fermentation vessels many decades ago. It exploded and blew a 30 foot diameter hole in the roof of the building. Not something you want to play around with. If you do any of this, make sure you have all your bases covered. One lapse of reason could take your head off.
 
Your yeast will also be dead long before the keg fails... I believe their limit is about 20PSI...

IMO, you're better off just installing an airlock in the keg. I've been successfully fermenting in sanke kegs for months now. Like it MUCH better than using corny kegs. For one thing, they're larger, so I can ferment more than 4.x gallons in them (for 5-6 gallons into keg/bottle). Plus, all I needed to do was remove the spear, clean, sanitize and they're ready to use. I've been using large universal bungs and airlocks on them so far. Going to try transferring with CO2 with the batch that's fermenting now. I have all the hardware I need to do it, so it shouldn't be bad at all...
 
Your yeast will also be dead long before the keg fails... I believe their limit is about 20PSI...
...

I would estimate a bit higher than that as wouldn't you be getting ~30PSI in a bottle conditioning @ 75 degrees F and that carbs up (i.e. the yeast isn't dead)? but you are right, they will be long gone before you get up to the 130(?) PSI that the corny is supposed to be rated at.
 
I have pictures in my gallery...

My original corny keg fermenter:
3114-corny-fermenter.jpg


Two 25L and the short pony keg...
4070-ss-fermermenters-25l-kegs-1-4-barrel-pony-keg.jpg


Got two tall pony kegs that I'm soaking with PBW right now. One is slated for use this weekend. The other probably the following brew session. Not sure when I'll use the short pony. Not even sure if I'm going to ferment in it.

I'll try to remember to get some shots of the fermenter in use this weekend. Since we might be hosting an all grain 101 'class' this time, I hope someone will take some pictures...
 
A couple of questions on the cornys….
How did you get the hole where the relief valve was? What did you use?
Do you think it would be possible or would it make sense have a valve welded on the bottom to be able to dump the trub like a Conical Fermentor?
 
Just use tools to remove the relief valve. The ones I've seens are made so that you can change/remove them without going to extreme lengths.

I wouldn't bother with a dump valve for the corny. For one thing, the thickness (at least the side walls) is rather thin. For another I don't see it as being necessary. If you want tp push the brew out of the keg and leave the trub behind, via gas, then get a spare liquid dip tube, shorten it and go with that method. You could then reinstall the original, adding some sanitized water, and push out the yeast cake.

If you don't want to modify the lid, then just remove one of the lock posts (and dip tube) and fit the post with a piece of tubing for an airlock amd/or blowoff hose.

Personally, I like fermenting in sanke kegs MUCH more. Especially with the fermenter conversion piece (got my first one last night, testing it starting this weekend).
 
I wouldn't bother with removing the relief valve. It's much simpler to just remove the "out" posts and diptube and just put a blow off tube directly on the threads. You can add a worm clamp to ensure it stays in place.
 
I think it was Budweiser that had a relief valve stick on one of their fermentation vessels many decades ago. It exploded and blew a 30 foot diameter hole in the roof of the building. Not something you want to play around with. If you do any of this, make sure you have all your bases covered. One lapse of reason could take your head off.

Happened at Abita a couple of years ago. Didn't happen as a result of fermentation, but from a pressure relief valve that failed during part of their cleaning process, which involves pressurizing the vessel they were cleaning.

http://blog.nola.com/tpnorthshore/2009/01/explosion_rocks_abita_brewery_1.html
 
Ferment in a keg connected to an empty 10lb co2 tank with no check valves.

Would you get a useable amount of Co2? and would that alleviate enough pressure on the keg?
 
Ferment in a keg connected to an empty 10lb co2 tank with no check valves.

Would you get a useable amount of Co2? and would that alleviate enough pressure on the keg?

I'm going to take a stab at that one without actually doing any work to back this up... No, don't do it.
 
That's probably over simplified. I would check with a local brew pub or microbrewery to see what the setup actually consists of. You should be able to alter it to your scale, but don't compromise the safety factor.
 
Why hasn't anyone mentioned a bleeder valve or spunding valve? It seems your making this more complicated than it needs to be.

Use a bleeder valve to blow off the excess pressure. Yeast don't die, beer done and carbonated fast.

Problem solved.
 
Why hasn't anyone mentioned a bleeder valve or spunding valve? It seems your making this more complicated than it needs to be.

Use a bleeder valve to blow off the excess pressure. Yeast don't die, beer done and carbonated fast.

Problem solved.

Where's this man's chicken dinner?
 
Why would you want to capture the initial stages of CO2 fermentation off gassing? It does not always smell that nice and I'd prefer it stays out of my beer. Best bet would be to follow the techniques outlined elsewhere on HBT for capturing the CO2 from the later stages of fermenting with a spunding valve set-up.

I think Sam got there first ;)
 
Do use an adjustable pressure relief valve and a pressure gauge to know exactly what your beer is doing. Do not allow the beer to go over 15 psi.

You might want to check with White Labs and Wyeast to see if they have any particular stains that work better under pressure.

I am gonna try this too. Seems the easiest option so far. I just gotta find a cheap adjustable relief valve now.
 
i haven't read all the way through this thread, but isn't there a fail safe considering the yeast will begin to die around 30ish psi? it seems like the yeast cell walls would collapse and all fermentation would cease long before the pressure hits 100 psi, and definitely before the keg fails. of course, it's not a good idea to allow the pressure to build to the point of killing the yeast (or putting significant stress on them), but i don't understand all of the concern that he's going to blow himself up with it.
 
tried, it so I thought I should post my comments.

I did it with three kegs. What I did was attach my gas quick connects to the kegs to let air out that way instead of in, then the blow off would go to through my three way manifold then I detached the nut on the end of the hose from the regulator and stuck it in a bottle of water for blow off.

It worked great for one of the kegs and the co2 was coming out into the water bottle just as planned. The other two however either got clogged at the post/quick connect or something cause they held pressure.

Once all the pressure was in it, there was only one way to get it out. Either the release valve or the post. There was so much pressure in it so I just pulled the release valve and locked it open on both of the kegs. I watched 2 gallons from each keg spew up into the ceiling and all over the kids bikes, mini van, etc. Wow I dont think I will do it again that way. To risky. Once the pressure is trapped you are screwed, its like a shoken up bottle. So I put what was left in buckets. I did however use a coke keg and removed a dip post and put a 1/2" hose with a water trap.

The only reason I tried this was to fit 4x batches in my fridge for ferm. Now I figure I can do 2x buckets and one coke keg to fit 3x in it to ferm at one time.
 
Some will say unless you can crop the yeast off the fermentation you may get some flavor issues, very much dependant on the overall conditons. You can start and go all the way with a top pressure, but it needs to be controlled, not just a Corney blow off! I think bad things may happen. If you fit a ball lock connector with a small air regulator in reverse fitted with a 0-60psi guage on the in side of the keg you will be in control. Look up your PVT=C table and choose your pressure based on your target CO2, and ferm temp. Should work just fine. Thats how we did it in the brewery, with a small trim just prior to bottling if necessary.
I have had flavor problems with some yeasts, probably because I have over pitched and over feed and not been able to off crop yeast. Its a one shot deal, I think if you get the recipe dialed in its a great way to have repeatability, problem is most of us are tweaking things all the time.
 
dang, just had another bad experience. I was able to fit two buckets and a coke keg in my temp controlled fridge last time now problem. This time the one in the coke keg plugged up the hole at one of the posts where I had the airlock. Luckliy I had a loose enough hose connecting the post to the airlock that I think released the excess pressure. They only thing is the otehr two btaches are still going and this one is not.

Should I re-pitch? I thought of getting some yeast from one of the other two batches later and re-pitching.
 
I was also thinking of doing this. I got some cheap 5 gallon soda kegs. They don't have a pressure relief valve, but they did come with one of these, http://stores.kegconnection.com/Detail.bok?no=484

I brew 2.5 gallon batches and was thinking about just fermenting in a 5 gallon keg, with this little valve depressor attached. Seems like it would work fine. Let it sit for 2 weeks and then transfer into an empty 3 gallon corny when one becomes available.
 
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