"Single" vessel fermentation and serve with pressure option

[seilenos]

I've been trying to find ways to "simplify" brewing. My most recent attempts have been fermenting and serving from the same corny keg. I fill up to the weld line and start with 10-12 psi to seal things up and let it ride. This has been great because when it is close to done I can ramp the spending value up to 20-25 psi and then cold crash and serve without transfer... always a PITA to prep and purge a second keg, then deal with the racking cane, then cleanup of all the stuff. I can just move it straight to the kegerator and serve.

While pressure does keep the krausen down it doesn't always stop it and sometimes have it coming through the spunding valve which, since I am using a cheapo bow-tie has gotten a little variable in keeping pressure ... I think some junk has caused it to be overly sensitive. I'm brewing a festbier right now and, although I confirmed the valve was set to 15 psi when I started I came downstairs the next day to find it was well over 30 psi when the valve got "stuck". Relieving the pressure causes the krausen to expand out the PRV and the valve making a bit of a mess.

This got me thinking on how I could augment this process to continue to brew 5 gal batches in a single ferment-and-serve vessel while also having the option to do pressure or not.

I have plenty of kegs and I wondered if it would be possible to use one as an extra large airlock... pull the gas fitting and tube from the fermenter and screw on a fitting with a hose connected to a second keg's beer-out (dip tube replaced with a gas line tube). The keg would be filled some amount with sanitizer. I could then put the spunding valve on the gas out of the second keg. If I wanted "no pressure", set it really low (1-3 psi). If I wanted to ferment under pressure, set it to whatever PSI I need.

This way, krausen has a place to go and, even if I don't put pressure on, it will stay out of the spunding valve. While I would then need to clean this second keg, that's probably the simplest part of the process as I have a keg washer and I would still not have to do any transfer to serve.

Anyone done something like this?
Are there fittings that can screw on to the keg posts and then attach a hose?

thanks.

 

[Broken Crow]

Why mess with the hardware?...if you're going to dedicate a second keg anyway, why not just make a gas>liquid line and simply insert your unmodified keg between your fermenting keg and the spunding valve?

 

[seilenos]

Why mess with the hardware?...if you're going to dedicate a second keg anyway, why not just make a gas>liquid line and simply insert your unmodified keg between your fermenting keg and the spunding valve?

My concern is the poppet getting clogged on either side. Maybe that is unwarranted ... especially since I have all the parts to do just that on-hand.

 

[Red over White]

If the threat off blowoff becomes present, I will put a 2 liter soda bottle with a carb tee on it. This allows the blowoff to safely go into the soda bottle while keeping the spunding valve clean.

 

[Broken Crow]

As long as the poppet closes back up when you disconnect, it's most likely that just plugging in the gas will clear it. If you're super concerned about that you could get the 'Carbonation Lid' Carbonating Keg Lid | Quick Beer Carbonator | Welded Gas-In Ball Lock Body Connect | 0.5 Micron Diffusion Stone | MoreBeer for the connection during ferment. It does sound though, like the major issue is with the spunding valve itself.
BTW: +1 on @Red over White 's pop-bottle suggestion with the carb-tee..I have a couple of those around for cleaning and sanitizing purposes and it'd take up a lot less space than a full sized keg.

 

[seilenos]

If the threat off blowoff becomes present, I will put a 2 liter soda bottle with a carb tee on it. This allows the blowoff to safely go into the soda bottle while keeping the spunding valve clean.

Wow ... that is a really simple, yet elegant, solution. I really appreciate the suggestion!

 

[Closet Fermenter]

I am bumping this older thread after considering the single vessel thing myself.
I was wondering about this; if the issue is the poppets clogging, couldn’t you simply take the poppet out of the post AND out of the connector to get the kek-keg connection in your opening post? This gives you a greater than 2 liter “catch” capacity, and requires no additional equipment purchase.
It does mean having to replace the poppet in the gas post for serving.

 

[seilenos]

Things I've learned in the three months since I started the thread:

Blow-off tube is dead simple for brews where I don't want pressure. Unscrew the gas connection, remove both it and the dip tube, store them in a glass filled with sanitizer from the brew day, use a hose over the threads into a small pitcher with sanitizer. After high krausen, remove the hose, replace the gas tube and post, pressurize to 5 psi (to seal) and add a spunding valve set to an appropriate PSI for the fermentation temp (usually mid 20s). This easily handled a tripel that had monster krausen.

For pressure ferments, over-pressurize with CO2 after pitch to seal everything and then back-off the spunding valve to 2 psi below target. When fermentation gets going tighten the valve a little to get to target. Not backing off the pressure has done wonders to keep krausen out of the valve.

 

[rkhanso]

I'm on my 2nd batch of fermenting in corny kegs. First was a cream ale, and currently just finished a Belgian Tripel.

I brew 10 gal at a time and have the 2 Fermentation corny keg gas ports Tee'd together and connected to the beer port on a 3rd "buffer" keg. The Blow-Tie is connected to the gas port on that 3rd keg. No chance of getting anything in the Blow-Tie this way - in my minimal experience. I've not yet used a blow-off tube. I also use a drop of fermcap in each keg prior to sealing and pressurizing.

Using the EVA barrier or clear tubing, you can see if there is anything flowing from the fermenting keg to the "buffer" keg. In the couple brews after I switched to fermenting in the corny kegs, the visible transfer from fermenting to buffer keg has been pretty minimal to none.

I have run the pressure around 12 PSI for most of the ferment.