Fermenting in a corny keg?

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BongoYodeler

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I'm thinking about trying this and am looking for pros and cons from those that do.

Has anyone tried this with neipas? If so, how successful were/are you?

A couple thoughts - I have an extra dip tube, ordered and on the way, that I plan on shortening a bit to be used for moving the beer to a serving keg. Thinking about either attaching tubing to the gas-in port to use as a blow off, or maybe air-in port on the fermenting keg to beer-out on a second keg to capture as a way of displacing oxygen on the serving keg.

Wondering how to best handle keg-hopping. Would it be better to dry hop in the fermenting keg only? Or in both the fermenting and serving kegs for hoppier ipas? Also, what's the best way of accomplishing this while holding oxygen levels down, but not necessarily going full-on LODO?
 
I’m planning on doing the same, 3 gal batches in a 5 gal corny. My plan is to build a spunding valve for the gas out port. I saw a thread here the other day where someone was talking about using a magnet to hold a stir rod in a hop sock to do dry hop additions. I will probably give that a try.
 
You can read about it in many threads here and on other forums. It's a thing, and like many aspects of brewing, there are lots of ways to do it.

About the dip tube - you can certainly cut one. But you can also:
  • Bend a standard tube rather than permanently cutting it
  • Switch out the long tube with a short gas tube, and attach silicone hose cut to the desired length
  • Replace a standard bottom feeding tube with a top draw tube
You can attach a QD to the gas IN post, and run a tube from that into a container of Star-San as a blow off. Or, you can capture fermentation CO2 in a second keg, either with spunding to retain pressure or with the blow-off on the second keg. Either way, it will purge that keg easily. Then you can transfer from the ferment keg into the serving keg with no oxygen exposure.

Here's a pic of my current ferment. On the right is a 3 gallon keg with 2.5 gallons of fermenting beer in it. On the left is a 2.5 gallon keg that will be used to serve the beer. The gas IN post on the larger keg runs to the liquid OUT post on the smaller keg. A spunding valve is attached to the smaller keg's gas IN post, holding 12.5 psi of pressure during the fermentation.

Inside the ferment keg, there is a standard un-modified dip tube running into a small stainless hop canister through a hole drilled in the lid. This should keep most particulate matter out of the transfer. I've done this in several ways so far; this is a new option for me.

Inside the serving keg is a top draw dip tube, so even if there is some sediment, it will settle to the bottom and the liquid drawn from the top will be clear.

Kegs.jpg
 
You can read about it in many threads here and on other forums. It's a thing, and like many aspects of brewing, there are lots of ways to do it.

View attachment 665141


That's a very cool setup you have there. What purpose is served by holding the 12psi pressure? Is that to keep a lid seal on the serving keg? Does it prevent the krausen from rising too high in the fermentor?
 
What purpose is served by holding the 12psi pressure?

Fermenting under pressure is a thing unto itself, and not strictly related to the keg as a primary vessel. This batch is a Vienna lager with S-189 yeast.

A pressurized environment limits production of esters and fusel alcohols, so temperature becomes far less important, particularly for lager yeast. The ambient temp here is about 67F. Also, you can partially carbonate the beer during primary, either by raising pressure towards the end or just by getting a head start.

Pressure also facilitates transfer from ferment keg to serving keg without an external CO2 tank. When this is done, I will connect the liquid outs, decrease pressure in the serving keg, and the beer should flow due to the pressure differential. I'll then attach a gas jumper and allow CO2 to flow back into the ferment keg, which should then hold the siphon until transfer is complete.
 
You can read about it in many threads here and on other forums. It's a thing, and like many aspects of brewing, there are lots of ways to do it.

About the dip tube - you can certainly cut one. But you can also:
  • Bend a standard tube rather than permanently cutting it
  • Switch out the long tube with a short gas tube, and attach silicone hose cut to the desired length
  • Replace a standard bottom feeding tube with a top draw tube
You can attach a QD to the gas IN post, and run a tube from that into a container of Star-San as a blow off. Or, you can capture fermentation CO2 in a second keg, either with spunding to retain pressure or with the blow-off on the second keg. Either way, it will purge that keg easily. Then you can transfer from the ferment keg into the serving keg with no oxygen exposure.

Here's a pic of my current ferment. On the right is a 3 gallon keg with 2.5 gallons of fermenting beer in it. On the left is a 2.5 gallon keg that will be used to serve the beer. The gas IN post on the larger keg runs to the liquid OUT post on the smaller keg. A spunding valve is attached to the smaller keg's gas IN post, holding 12.5 psi of pressure during the fermentation.

Inside the ferment keg, there is a standard un-modified dip tube running into a small stainless hop canister through a hole drilled in the lid. This should keep most particulate matter out of the transfer. I've done this in several ways so far; this is a new option for me.

Inside the serving keg is a top draw dip tube, so even if there is some sediment, it will settle to the bottom and the liquid drawn from the top will be clear.

View attachment 665141
Thanks for this. You've answered some questions and will likely spur a couple more once I give this more thought. Busy day however, and I'll have to get back to you as I'm calling it a day. Thanks again...
 
You can read about it in many threads here and on other forums. It's a thing, and like many aspects of brewing, there are lots of ways to do it.

About the dip tube - you can certainly cut one. But you can also:
  • Bend a standard tube rather than permanently cutting it
  • Switch out the long tube with a short gas tube, and attach silicone hose cut to the desired length
  • Replace a standard bottom feeding tube with a top draw tube
You can attach a QD to the gas IN post, and run a tube from that into a container of Star-San as a blow off. Or, you can capture fermentation CO2 in a second keg, either with spunding to retain pressure or with the blow-off on the second keg. Either way, it will purge that keg easily. Then you can transfer from the ferment keg into the serving keg with no oxygen exposure.

Here's a pic of my current ferment. On the right is a 3 gallon keg with 2.5 gallons of fermenting beer in it. On the left is a 2.5 gallon keg that will be used to serve the beer. The gas IN post on the larger keg runs to the liquid OUT post on the smaller keg. A spunding valve is attached to the smaller keg's gas IN post, holding 12.5 psi of pressure during the fermentation.

Inside the ferment keg, there is a standard un-modified dip tube running into a small stainless hop canister through a hole drilled in the lid. This should keep most particulate matter out of the transfer. I've done this in several ways so far; this is a new option for me.

Inside the serving keg is a top draw dip tube, so even if there is some sediment, it will settle to the bottom and the liquid drawn from the top will be clear.

View attachment 665141

That is some spunding valve you have there. Was it a pre-built thing or something you created?
 
@ba-brewer , it's a SPUNDit, the guy who makes them lives in CA and sells them on eBay (search for that term). It's really well engineered, with two ports and an included airlock. Adjustments are very precise.
 
You can read about it in many threads here and on other forums. It's a thing, and like many aspects of brewing, there are lots of ways to do it.

About the dip tube - you can certainly cut one. But you can also:
  • Bend a standard tube rather than permanently cutting it
  • Switch out the long tube with a short gas tube, and attach silicone hose cut to the desired length
  • Replace a standard bottom feeding tube with a top draw tube
I have a dip tube ordered and it should arrive today. I'm going to try cutting it rather than bending it. They're cheap enough as to not worry too much about it.
You can attach a QD to the gas IN post, and run a tube from that into a container of Star-San as a blow off. Or, you can capture fermentation CO2 in a second keg, either with spunding to retain pressure or with the blow-off on the second keg. Either way, it will purge that keg easily. Then you can transfer from the ferment keg into the serving keg with no oxygen exposure.
Right in line with what I've been thinking of doing.

Here's a pic of my current ferment. On the right is a 3 gallon keg with 2.5 gallons of fermenting beer in it. On the left is a 2.5 gallon keg that will be used to serve the beer. The gas IN post on the larger keg runs to the liquid OUT post on the smaller keg. A spunding valve is attached to the smaller keg's gas IN post, holding 12.5 psi of pressure during the fermentation.
Sweet.

Inside the ferment keg, there is a standard un-modified dip tube running into a small stainless hop canister through a hole drilled in the lid. This should keep most particulate matter out of the transfer. I've done this in several ways so far; this is a new option for me.

Inside the serving keg is a top draw dip tube, so even if there is some sediment, it will settle to the bottom and the liquid drawn from the top will be clear.

Interesting. I think I read about this, maybe an article from Jamil? I'd love to see a pic of it if possible. You mentioned you tried several ways so far (bolded above). What's worked for you? What hasn't? I'm not sure I want to alter the hop canister lid, though they aren't THAT expensive I suppose.
 
I bought 2 of those keg-opening-sized hop canisters and frankly, I rarely dry hop, so I decided to sacrifice one of them for this purpose. Someone here on HBT mentioned that this was his most successful method of transferring from the fermenter keg, so I thought I'd try it.

I first tried bending a standard dip tube. It's hit or miss, as you don't really know where the trub will end up. You'll either pull up gunk, or more likely, leave too much behind.

Next up was a floating dip tube. This works better since it pulls from the top right from the start, but is a little more unpredictable once it reaches the bottom. They have a floating ball on top of the liquid, but the tube opening itself hangs below the surface. So you can see how there might be an inch of clear beer available, but the tube opening is dragging in the gunk.

Obviously, both of these methods work - and if you're kegging, who cares if you drag a little mess into the serving keg. It'll get blown out anyway. But you know... always looking for improvements, and excuses to tinker!
 
I have a dip tube ordered and it should arrive today. I'm going to try cutting it rather than bending it. They're cheap enough as to not worry too much about it.
Just cut it well. I've had issues in the past with unsanitary cuts and having infection issues. Bending really is a better option.
 
@BongoYodeler , I finally transferred beer from the keg in the photo above, so I can show you the inside after this occurred. It worked very well! Just the right amount of yeast and trub was left behind, since the stainless canister prevents pickup from the very bottom of the keg, and also in a small radius around the center.

IMG_6897.JPG
IMG_6896.JPG
 
Fermenting in kegs is really great. Really I think the only downside is not being able to do big enough batches to fill a 5 gallon keg. Aside from that, tons of advantages. I think you're essentially getting almost everything you would from a SS conical or unitank but at a fraction of the cost. I tried using the CBDS but have come to loathe it and use a setup similar to previous post, with slightly shorter cut diptube inside a SS hop canister. I usually wrap it with a mesh bag for extra filtering. My transfers this way have been pretty much perfect, no clogs and no beer left behind, aside from what the hops soak up. Even with never bagging my hops.

The way I minimize O2 from dry hopping is I'll either dry hop at end of fermentation when there's still some activity, or I'll load the dry hops into a 2nd keg at start of fermentation and hook it up with a jumper so it's purged during fermentation, then after crashing the yeast I transfer over without having to open anything. Maybe it's overkill but I've become really anal about O2 exposure for my hoppy beers, because I've seen how easily you can get degradation of flavor with sloppy processes.
 
@BongoYodeler , I finally transferred beer from the keg in the photo above, so I can show you the inside after this occurred. It worked very well! Just the right amount of yeast and trub was left behind, since the stainless canister prevents pickup from the very bottom of the keg, and also in a small radius around the center.

View attachment 665826 View attachment 665827
Very nice. I may explore that option down the road. For hop exposure I can see where it might be more beneficial for all the hops to free float rather than confine them within the canister.

Related - I trimmed an inch off my new dip tube. Cleaned the outside with a table grinder, and the inside with a small rat-tail file. Seems really smooth to the eye and touch. Still a bit concerned for possible infections as mentioned by @beersk I plan on doing my first transfer with this later today.
 
Re: hop exposure - there are no hops in the canister. Actually if I were dry hopping, I’d let them sit free in the beer. The canister is more like an inline filter on the dip tube.
 
Re: hop exposure - there are no hops in the canister. Actually if I were dry hopping, I’d let them sit free in the beer. The canister is more like an inline filter on the dip tube.

Is the canister sitting unlevel on the bottom how you were able to drain below the solid bottom piece or did something move before the pic?

I have a couple of those canister collecting dust, looks like a good use for them.

Thanks for the info on the ebay spunding valve too. Maybe a little bit more expensive but it looks like a more solid well integrated unit. I like the addition of the airlock.
 
Is the canister sitting unlevel on the bottom how you were able to drain below the solid bottom piece or did something move before the pic?
Mine sits level. In theory I would lose about 1/2 inch of liquid because of the solid bottom of the hop canister but almost all my beers are heavily dry hopped so that's all pretty much hop matter that I'm losing regardless.

I've thought of drilling the hole for the dip tube in the solid underside of the cannister so the top with holes would sit on the bottom, thus possibly getting a little more liquid but I also might suck in more hop matter that had crashed to the keg bottom.
 
Mine is almost level. There's a slight tilt to it. But @VirginiaHops1 explains it well (and thanks for the tip on doing this!): The canister has a solid bottom and a perforated lid. The mesh on the side starts a short distance above the bottom, so most of the trub on the keg floor doesn't reach the holes. Sure, a little trub probably enters the canister during fermentation by drifting in. But even teeny break particles would rather follow gravity to the bottom than enter the canister from the side.

On topic with pressurized keg fermentation; my Vienna lager tastes great after only 8 days in the keg so far. Cloudy and warm, but somehow clean and with the exact malty flavor I had been hoping for. I'm pretty stoked for it to finish up in the serving keg, then get chilled and conditioned for a couple of weeks. I'm not one of those people who thinks any old crap tastes good, either, or who generally enjoys green beer. I was impressed.
 
Re: hop exposure - there are no hops in the canister. Actually if I were dry hopping, I’d let them sit free in the beer. The canister is more like an inline filter on the dip tube.
I that reply was to my post I agree. But I was talking about my current method of dry-hopping in the keg, which is hops in the canister. Free floating outside the canister seems like a much better idea.

Related - my hop canister is screen all around, even on the bottom. The screw-on perforated lid is the solid component on my canister. So, although mine might get low enough to transfer all beer I'd be concerned that a full length dip-tube might possibly rip through the bottom screen. My shortened dip-tube obviously wouldn't have that issue.
 
I ferment in corny kegs the ghetto way. No spunding, no transfer to a serving keg, no fancy techniques to dryhop. I just rack from the brew kettle into the keg, then 2-3 weeks later I put it on gas, and then start drinking it a week later. I usually get a pint of sludgy beer and then its all good. When I dry hop, I just open it up and drop a bag of hops in and close it back up, then put it on gas and purge it a few times.

Works good for me!
 
Yes, that was my entry into the keg-fermenter world also. I did install a top draw tube, though.

What happens is that the beer is really clear and great until about 2/3 of the way down, then you discover that it still tastes fine, but is gradually becoming hazy. And of course it only goes downhill from there. That's the trade-off with a floating dip tube in the keg-fermenter scenario - early gratification, but with a compromise later. With a regular dip tube, as long as you can blow out the crap at the bottom, you're good to go from that point til the very end.
 
Last week I brewed a 3 gallon American wheat that I fermented in a 5 gallon corny with a cut dip tube. Easiest fermentation and transfer to my serving keg I have ever done. During primary I removed the pressure release valve and attached the airlock there. When fermentation was complete, I installed the pressure relief valve and then started carbonating the beer while doing a 5 day cold crash. This got me thinking about using a 1/4 Barrel Sanke keg for 5.5 gallon batches. I have a NEIPA currently fermenting in a 1/4 barrel keg. I purchased the Sanke Ball Lock conversion from NorCal Brewing for the Sanke keg. The dip tube is adjustable but I ended up cutting the tube so the Sanke keg would fit in my mini fridge. I removed the gas post and installed a S airlock. When I add my first dry hop, I’ll install the gas post and attach a gas connection with an airlock. After the final dry hop I’ll remove the airlock and attach CO2 to start carbonation and cold crash. I have a tilt hydrometer so I can monitor the fermentation without taking samples or opening the fermenter. I feel this will minimize O2 exposure and make cold crashing, carbonating and jumping to serving keg very easy.

https://www.norcalbrewingsolutions.com/store/Sanke-Keg-Ball-Lock-Serving-Connect.html
E919BA65-717C-4CF2-9EA9-BED209C19137.jpeg
0DEC0B26-BA10-45C8-841E-0F383398913B.jpeg
 
I am going to try pressure fermenting in a Corny keg, but I'm still a little undecided on how to avoid all of the trub at the bottom. Cutting the dip tube alone probably won't be enough because I will likely dry hop it pretty hard and it'll still clog.

One option a lot of people mention is the floating dip tube, but I get the impression this would leave quite a bit of beer in the bottom as the actual intake sits about an inch below the surface of the water, which I would imagine means you'll never get that last inch of beer out as it will hit the trub and you'll have to stop. That's at least a litre of beer there.

Alternative is doing something like McKunkle did above which seems like it would allow you to get all of the beer out and filter it as it's going.

Are there any pros/cons to either of these methods?
 
With hop matter in the keg you have no choice but to use a screen somewhere. With stuff that's readily available, it's likely to be either a Clear Beer Draught System with its integrated mesh filter, or a hop canister. The hop canister can either contain the hops, or it can shelter a traditional dip tube as I've pictured earlier in the thread.

It's been a few months since this thread was begun, and one thing I've had happen since is the re-suspension of trub over time. It caused me to prematurely dump one keg, and cringe through part of another. Basically, since the spent yeast and trub never leave the keg, we count on it compacting on the bottom and staying there for the duration. But a couple of times - with lager yeast, specifically - it did not. Now, I tend to take a long time finishing a keg, and this was after a couple/few months. So maybe it won't happen to most of you.

I think it's best if one can get over the typical obsession with recovering every last drop of beer. Beer fermented in a keg equipped with a floating dip tube, where the detritus is never dispensed, simply does not have the ability to give that to you. You have to live with more volume discarded on the bottom than you're used to. But really, this is exactly what you'd discard at the beginning after a traditional racking to your serving vessel. So you're not wasting anything extra, you're just waiting to discard it at the end.
 
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The easy way is to snip the dip tube and transfer over to a serving keg. A lot of cool stuff in the works for fermenting and spunding in a keg.
 
With hop matter in the keg you have no choice but to use a screen somewhere.

Thanks for your reply. You make a good point here - with the hop matter floating around, the screen is going to be necessary. I think your method looks good, I'll try to get myself a cannister.

It's been a few months since this thread was begun, and one thing I've had happen since is the re-suspension of trub over time. It caused me to prematurely dump one keg, and cringe through part of another. Basically, since the spent yeast and trub never leave the keg, we count on it compacting on the bottom and staying there for the duration.

Is this happening in a serving keg that you transferred to, or are you serving out of the fermenting keg? I intend to transfer it, and I would have thought that most of the trub would have been filtered out in that process. In any case, I'm not actually looking for a super clear beer, I'm mostly going to do NEIPA's so it should be cloudy, I'm just thinking about a way to do it so that the liquid out port and dip tube doesn't get clogged.

I think it's best if one can get over the typical obsession with recovering every last drop of beer.

The amount you got out of the keg above seems just fine.
 
The worst example of floating bits after months on tap was in a lager that I had fermented and served from the same keg, no transfer, using W 34/70 yeast. I had done that before with success, but with ale yeast, US-05 probably. So I do think it's yeast-dependent.

Transferring is clearly a safeguard against that. But to me, the most annoying thing about fermenting in kegs - which is otherwise great - is transferring. You don't have the benefit of gravity, so you need pressure to push it out. I hate to use bottled CO2 because it's not easy for me to get it locally. If that's not a factor for you, then that problem evaporates.

Fermenting with a spunding valve can work, though; even building up just a few psi would facilitate beer flow up and out of the liquid port, and down tubing into a serving keg. Then just open up the PRV's on both kegs to keep things going.

Also I'm on the fence with floating dip tubes. As I mentioned above, it might be preferable to blow out sediment from the bottom at the beginning "once and for all" vs. to risk having it become suspended later. Depends how patient one is about clearing at the beginning.
 
Yeh, I was thinking about using a spunding valve to ferment under pressure which would leave pressure in there to do the transfer. Also, CO2 is pretty readily available here in Munich, hardware shop just around the corner from me has bottles to swap out and only 20 euros for 10 liters so I'm not too bothered about the waste.

I see your point though, still easier if you don't do the transfer at all. I guess I can give it a shot both ways.

I think the main advantage of fermenting in kegs is that it's super cheap and available, allows pressure fermenting, and allows the closed transfer right out of the box. I can see how some fermenters like the Williams BrewKeg are superior and nice - but at 10 times the price they'd want to be. And although the Fermentasaurus is affordable (although still 3 times the price of a keg), it has its own issues and is flimsy and difficult to fit in a small fridge (if you want temperature control).

Kegs to me seem to give the best overall best price/quality/functionality.
 
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The worst example of floating bits after months on tap was in a lager that I had fermented and served from the same keg, no transfer, using W 34/70 yeast. I had done that before with success, but with ale yeast, US-05 probably. So I do think it's yeast-dependent.

Transferring is clearly a safeguard against that. But to me, the most annoying thing about fermenting in kegs - which is otherwise great - is transferring. You don't have the benefit of gravity, so you need pressure to push it out. I hate to use bottled CO2 because it's not easy for me to get it locally. If that's not a factor for you, then that problem evaporates.

Fermenting with a spunding valve can work, though; even building up just a few psi would facilitate beer flow up and out of the liquid port, and down tubing into a serving keg. Then just open up the PRV's on both kegs to keep things going.

Also I'm on the fence with floating dip tubes. As I mentioned above, it might be preferable to blow out sediment from the bottom at the beginning "once and for all" vs. to risk having it become suspended later. Depends how patient one is about clearing at the beginning.
I wonder how some of the Kveik strains would be for keg-fermenting. I've brewed two beers with Kveik (Voss and Lutra), but fermented in my Speidel fermenter. In both cases they dropped fast, hard, and tight.
 
I agree that some yeast present no problem at all with the ferment-and-serve method.

To me, a keg with a bottom-mounted ball valve and spigot would be the perfect fermenter! Stainless, pressure, gravity transfers, and easy sampling all in one. I would happily sacrifice one of my older kegs to try it. Maybe that's a good project.
 
Transferring is clearly a safeguard against that. But to me, the most annoying thing about fermenting in kegs - which is otherwise great - is transferring. You don't have the benefit of gravity, so you need pressure to push it out. I hate to use bottled CO2 because it's not easy for me to get it locally. If that's not a factor for you, then that problem evaporates.

Not sure if you're already aware of this or have tried it before, but you can certainly use gravity to do a closed transfer to siphon the beer from fermenting keg to serving keg. You just need to position the fermenter above the serving keg and create a pressure differential (~5psi should be enough) to start a siphon. This could be achieved by spunding, sealing the fermenter at the very end of fermentation, or with a quick blast of CO2. Once the siphon gets started, you connect the gas in posts from both kegs together to equalize the pressure and let gravity do its thing. This process has worked every time for me, except for heavily dry hopped beers which sometimes need a little extra "push".
 
Full disclosure: I just setup a BRUTUS type single tier HERMS setup using keggles. I havent ever done a AG brew (I've done many of the single pot and extract brews but decided to get more invested). I have a homemade 2 corny keg kegerator. Wanted to provide a tiny bit of context for my question:

My question is about how much volume (for fermentation) do you put in a 5 gal corny keg? My target is to have 11 gallons at the end of a brew (knowing there will be additional volume losses after fermentation). I cant recall what the risk is to having additional head space in a fermentor (hope I am using the correct terms here). When i've done extract brewing (5 gal batch) I've filled my 6 gallon brew bucket and then transferred it, for secondary fermention, to a 6 gallon glass carboy several days later. Anyways from reading this thread (thanks for all the approaches shared) it seems like some of you (@McKnuckle) transfer directly to your modified fermenting corny keg and then transfer from there to the serving keg (and thus not doing the extra settling step I'm used to with my limited extract brewing experience), is this correct?

Thanks for any info you can share, hope I didnt derail too far from the OP's question.
 
Regarding the question you tagged me about... That's correct; I do any settling in the serving keg itself.

My best method, not always followed to a tee, is:
  1. Chill wort most of the way down in the kettle
  2. Rack all wort including trub to a clear carboy, plug with a stopper, refrigerate
  3. After trub settles (1-2 hrs), siphon clear wort above the trub into fermenter
  4. Ferment either to FG or, if spunding, within a few gravity points
  5. Closed transfer into serving keg equipped w/floating dip tube, and optionally spund
  6. Refrigerate serving keg, place on gas at serving pressure, and condition 2-3 weeks
 
As long as you are venting the keg to release fermentation CO2, the headspace will be easily and quickly purged. You could ferment 1 gallon in there.
 
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