Fermenting in a Keg

[yard_bird]

I'm a bottle conditioner and I won a used corny keg at homebrew club. I'm wondering if I can use this as a fermenter with a PRV set very low (no idea how low), ferment, and then prime, rack to bottles, and bottle condition. Is this feasible? Getting a kegerator set up isn't quite an option due to cost/space/long drive to swap out CO2 tanks.

Thanks all.

 

[mac_1103]

You could use a wide open spunding valve, but I would just remove the gas post (or at least the poppet) and hook up a blow off tube. Or you could remove the PRV and fit an airlock onto the lid instead. Kegs make excellent fermenters and open up a lot of possibilities like pressure fermenting and oxygen-free bottling, but those would require investment in some additional equipment.

 

[yard_bird]

Thanks for the quick reply mac.
I think I’m going to use this for fermenting high gravity, oak aged beer. My thought process is after most of the fermentation is complete (say 11 days for my Belgian quad recipe), I swap the airlock for a spunding valve just to make sure I don’t get o2 ingress over the course of 6-8months. When I’ve done this in either buckets or carboys (I guess my carboys were a little oversized), the wort will darken/go stale after a couple months, which I attribute to O2 ingress.

I would likely add priming sugar right to the keg on bottling day and rack into bottles. Sure, there’ll be O2 introduced, but much less than sitting in a bucket for half a year. Any thoughts?

 

[fluketamer]

that sounds good

 

[mac_1103]

I would likely add priming sugar right to the keg on bottling day and rack into bottles. Sure, there’ll be O2 introduced, but much less than sitting in a bucket for half a year. Any thoughts?

You can inject the priming sugar into the keg with a syringe to avoid opening the lid, but again that requires a small investment. Here's an example, but you can DIY something like this pretty easily (with a bigger syringe too). But the other problem with this is the yeast cake. If you don't mix the priming sugar into the beer well you will get uneven carbonation. If you do shake the keg to mix it well you will stir up all the trub and it will wind up in your bottles. So you might want to consider dosing the priming sugar into the individual bottles instead.

If you're willing to invest in a miniregulator (and maybe a floating dip tube) you could use a sodastream CO2 cylinder to push the beer out of the keg and into the bottles. If you're willing to invest in or build a counterpressure bottle filler you could prime and condition in the keg. But you need to be able to get both the keg and the bottles very cold for that to work well.

edit - of course, it's hard to inject oak into a keg

 

[Pennine]

I wouldn't mix bottling sugar in the keg, if you mix it up you will get excessive amounts of yeast in the bottle, or uneven bottle carbonation if you don't. Probably better to use carb tabs in the bottle. Do you have a CO2 tank?

 

[yard_bird]

Thanks for the feedback all.

I don’t have a co2 tank. Trying to avoid that because it’s a bit of a drive for me to get it refilled. Soda stream option may work for since I have one of those….

 

[fluketamer]

sodastream kegging is the next logcal step after bottling and before full size kegging IMO