Can I ferment completely closed in corny keg under pressure?

[Mayday99]

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.

 

[Paramecium]

None of us were trying to be douches I promise. This board is full of friendly people and all I and the others were trying to say without being too condescending was that this could go very bad. I am glad you decided against it for the time being. And Mattd2 thank you for doing the math work, I saw that equation while at work and didn't have time to work it out, I'm glad you did. Fermenting beer can produce an incredible amount of Co2 and sealing that in a closed vessel can be extremely dangerous, even more so while bypassing safety measures designed for the vessel.

 

[Golddiggie]

You can still ferment in the corny, just not have it air/pressure tight. Install an airlock into it (you have three options built into the keg) and you're good to go... Just be sure to use some fermcap first, or install a blow-off tube for the first few days...

 

[mattd2]

Just be sure to use some fermcap first, or install a blow-off tube for the first few days...

Or don't brew full 5 gallon batches. I have done 3 gallons of apfelwein and ginger beer (7% abv) in 5 gallon cornies with nothing more than my gas in hose stuck into a jar of water. Beer would probably pump out a bit more kruesen though

 

[Golddiggie]

I'd rather ferment closer to the 5 gallon mark, of beer, than closer to 3 gallons. I had zero issues with the batch that started in the corny. I actually picked up four 5.16 gallon Sanke kegs last week that I'll be using for both primaries/fermenting and aging in... Already have what I need to use two of them (bung for one, cap for the other)... Plan to get the parts to use the other two within the next few weeks. Planning on phasing out some of my PET carboys in favor of the kegs... Now, if only I could get my hands on some slim/tall 1/4 barrel kegs (for cheap money)... :rockin:

 

[redalert]

I went ahead and installed a blowoff tube in the "out" post. My "supermoon pils" will be happily fermenting in the coming days with pressure release

 

[Golddiggie]

I went ahead and installed a blowoff tube in the "out" post. My "supermoon pils" will be happily fermenting in the coming days with pressure release

Nice... Let us know how things go... I'm really starting to enjoy using kegs for fermenting and aging... I think they're easier to move around than either carboys or buckets...

 

[redalert]

Nice... Let us know how things go... I'm really starting to enjoy using kegs for fermenting and aging... I think they're easier to move around than either carboys or buckets...

Yeah not to mention cleaning. I can't stand cleaning a grimy carboy.

 

[kanzimonson]

Dang, with a name like Supermoon Pils, it might have been fun to make a corny rocket.

 

[ReefkprZ]

I went ahead and installed a blowoff tube in the "out" post. My "supermoon pils" will be happily fermenting in the coming days with pressure release

umm if you put it on the "out" post any pressure build up inside the keg is going to push liquid out from the bottom not gas from the top, you want your blow off on the "IN" post, so your venting gas off the top.

unless of course you removed the pick up tube from the out post when installing the blow off then it wont matter.

 

[stunsm]

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.

 

[winnph]

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.

 

[Golddiggie]

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.

 

[redalert]

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.

 

[Golddiggie]

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... 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.

 

[redalert]

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... 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.

 

[Golddiggie]

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...

 

[gracho]

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.

 

[Golddiggie]

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...

 

[mattd2]

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.

 

[Ruffins]

Would you guys post pictures of what you have working here?

 

[Golddiggie]

I have pictures in my gallery...

My original corny keg fermenter:

Two 25L and the short pony keg...

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...

 

[Ruffins]

Perfect, thanks!

 

[Ruffins]

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?

 

[Golddiggie]

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).

 

[TheMan]

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.

 

[Clementine]

Two 25L and the short pony keg...

Golddiggie, how do you clean the Sanke kegs after fermentation, does a PBW soak and rinse get the krausen off this inside?

Clem

 

[joelmole]

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

 

[gtwarren1966]

Sounds to me like you want to make a beer bomb

 

[cheezydemon3]

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?