Pressurized Closed Loop Corny Keg Fermenting

[schematix]

First. No disrespect to the thread starter..

None taken.

 

[4of7]

Do you mind sharing your yeast harvesting technique with the kegmenter please? Cool setup!

Keg's hanging out

 

[4of7]

Keg washing prep for in line carb

 

[4of7]

Do you mind sharing your yeast harvesting technique with the kegmenter please? Cool setup!

It is the same process with corny kegs.

 

[Gnomebrewer]

I've been watching this thread for a while, and finally got around to fermenting in kegs recently. Now about a dozen batches in and finding it's really easy and produces some great beer. I had previously tried spunding after running the primary ferment in plastic fermenters (as part of a LoDo trial) but prefer fermenting in cornies and then transferring to serving kegs via a closed loop - it's so easy. This thread has been very helpful, so thankyou! I think, after many years of brewing and hundreds of batches, that this has made one of the biggest improvements to my beer.

 

[Siouxerbrewer]

It is the same process with corny kegs.

Thanks for the detailed reply! I’m building a similar setup for now and this thread has been very informative. It’s going to be awhile before I get to brewing again, but when I do I hope to contribute to this thread.

 

[4of7]

Thanks for the detailed reply! I’m building a similar setup for now and this thread has been very informative. It’s going to be awhile before I get to brewing again, but when I do I hope to contribute to this thread.

I didn't start the thread., I just posted on it... I was chasing info like many..if you get a beer shower doing this.. happened to me
Lol... couple of times... learning curve so I tell myself..

 

[Siouxerbrewer]

I'm working on something new for this thread. I think it's going to be awesome. Unfortunately I won't be brewing for at least 3 months (work) so I will have to post back then.

 

[leesmith]

I'm working on something new for this thread. I think it's going to be awesome. Unfortunately I won't be brewing for at least 3 months (work) so I will have to post back then.

Any reason you can’t share those ideas now?

 

[stickyfinger]

I'm working on something new for this thread. I think it's going to be awesome. Unfortunately I won't be brewing for at least 3 months (work) so I will have to post back then.

is it Beer Force?

 

[Siouxerbrewer]

Lol. Yes it is Beer Force I'm working on a way include temp control (neoprene covering a fermwrap on the keg) and a thermowell in the lid, along with a top croppingblow off assembly. Ferment in the keezer, top cropping the yeast.

 

[stickyfinger]

anyone have any more input on fermenting and serving from the same keg using a CBDS? i did a split batch at about 1.076, using 95% pale malt, 2.5% each of munich 10L and carahell 10L. added 6 oz citra to one and mosaic to another (4G in a 5G keg with 0.25G start to each) on day 3 and then rack on day 8. they taste absolutely amazing one day after chilling. i hope they don't get grassy. i've had some of my ferment in and serve in the same kegs go grassy, but they were using the german hops - the hallertau blanc in particular tasted awful. it was like 6 oz in a 4.5G volume fermented and served from the same keg. malt was all-Pils.

 

[cheesebach]

anyone have any more input on fermenting and serving from the same keg using a CBDS? i did a split batch at about 1.076, using 95% pale malt, 2.5% each of munich 10L and carahell 10L. added 6 oz citra to one and mosaic to another (4G in a 5G keg with 0.25G start to each) on day 3 and then rack on day 8. they taste absolutely amazing one day after chilling. i hope they don't get grassy. i've had some of my ferment in and serve in the same kegs go grassy, but they were using the german hops - the hallertau blanc in particular tasted awful. it was like 6 oz in a 4.5G volume fermented and served from the same keg. malt was all-Pils.

I’ve had some good luck doing this with beers without any dry hops, and I think it may become my standard process for those. Not necessarily because I’ve noticed a quality difference, just because it’s easy. I only have one CBDS for now though - waiting to try it with a few more batches before I go all in on a couple more.

However, for IPAs, I think I’ve been noticing that I need some sort of post-fermentation dry hop for my tastes. For those, I’ve had issues opening the keg to add hops with any sort of carbonation level already present. My best results so far with NEIPA have been fermenting and spunding with a bio transformation hop at day 1-2. The fermenter has a full length screen around the dip tube and I chill to 60F after fermentation to drop the hops. Then, I water purge and add dry hops to a serving keg with the CBDS while flowing in CO2. From there, I can transfer under pressure without a foam volcano.

I will probably try it one more time, saving all dry hops for post fermentation and seeing if having no dry hops present already in the pressurized fermenter makes it any easier to open without a mess.

 

[leesmith]

I’ve had some good luck doing this with beers without any dry hops, and I think it may become my standard process for those. Not necessarily because I’ve noticed a quality difference, just because it’s easy. I only have one CBDS for now though - waiting to try it with a few more batches before I go all in on a couple more.

However, for IPAs, I think I’ve been noticing that I need some sort of post-fermentation dry hop for my tastes. For those, I’ve had issues opening the keg to add hops with any sort of carbonation level already present. My best results so far with NEIPA have been fermenting and spunding with a bio transformation hop at day 1-2. The fermenter has a full length screen around the dip tube and I chill to 60F after fermentation to drop the hops. Then, I water purge and add dry hops to a serving keg with the CBDS while flowing in CO2. From there, I can transfer under pressure without a foam volcano.

I will probably try it one more time, saving all dry hops for post fermentation and seeing if having no dry hops present already in the pressurized fermenter makes it any easier to open without a mess.

So is that IPA already carbonated before your transfer to the serving keg with hops in it?

 

[cheesebach]

So is that IPA already carbonated before your transfer to the serving keg with hops in it?

Yep, it seems that as long as the serving keg is at or near the same pressure of the spunding keg and the whole closed system stays under pressure during transfer, there isn’t much foaming issue when transferring onto the hops in the SK. For me, it seems like the floating dip tube in the SK may be necessary when going this route though. The first time I tried it, I was using a full length dip tube (the one Janish recommends), and while the transfer went well, I was getting a lot of astringency from the hops when pulling from near the bottom of the keg.

 

[leesmith]

Yep, it seems that as long as the serving keg is at or near the same pressure of the spunding keg and the whole closed system stays under pressure during transfer, there isn’t much foaming issue when transferring onto the hops in the SK. For me, it seems like the floating dip tube in the SK may be necessary when going this route though. The first time I tried it, I was using a full length dip tube (the one Janish recommends), and while the transfer went well, I was getting a lot of astringency from the hops when pulling from near the bottom of the keg.

Thanks
I’m going to transfer my beer off the yeast into a keg with hops and the Scott Janish dip tube screen and I was thinking about adding some sugar to carb it at the same time as dry hop....then once carbonated and cold conditioned, transfer to a serving keg.
My worry is the screen could cause too much foaming during transfer.

 

[BeerFst]

Thanks
I’m going to transfer my beer off the yeast into a keg with hops and the Scott Janish dip tube screen and I was thinking about adding some sugar to carb it at the same time as dry hop....then once carbonated and cold conditioned, transfer to a serving keg.
My worry is the screen could cause too much foaming during transfer.

Your serving keg just needs to be pressurized during transfer. If you go back to the start of the thread that’s why they pressurize the serving keg with the fermentation co2. I don’t do the full method and instead do what cheesebach described above with a cbds. During transfer to my serving keg I move my spund to the gas in on the serving keg and set it to 5 or 10 psi, then do a force transfer over with a few psi above my spund setpoint. Havent had foaming problems yet

 

[VirginiaHops1]

I haven't dry hopped under pressure yet, so it would be cool if some of you folks who are doing so already and getting results they are happy with could outline their schedule eg. What pressures, for how long, when you are adding your dry hops, whether the whole fermentation is under pressure or just spunding, etc

To add another data point to the thread, I recently tried dry hopping under pressure for the first time. I closed transferred after 8 days in primary to a purged keg with bagged dry hops and put it under about 4-6 psi(read with spunding valve). Recipe was Trillium-ish, 70% 2 row, 20% white wheat, the rest crystal and carapils. Galaxy/columbus hops. I tried a taste yesterday after 4 days in the keg and the hop flavors and aroma seemed very subdued, so I'd say I'm less than impressed BUT it's very early so I'm going to give it another week in the keg and try again.

 

[schematix]

did you monitor gravity before and after day 8? an ale likely was done around day 3-5. adding hops after that is how you oxidize and get the subdued flavors.

 

[IslandLizard]

with bagged dry hops [...] after 4 days in the keg and the hop flavors and aroma seemed very subdued

That may be due to the bag being much too constrictive. The beer can't permeate freely to extract the flavor and aroma compounds from the (compacted) hop mass, unless the bag is very roomy and you agitate it periodically. At what temps is that keg being kept?

I closed transferred after 8 days in primary to a purged keg with bagged dry hops

How did you purge the keg and add the hops? How did you do that, eliminating O2 content and ingress?

 

[VirginiaHops1]

did you monitor gravity before and after day 8? an ale likely was done around day 3-5. adding hops after that is how you oxidize and get the subdued flavors.

I forgot to check gravity but I suspect it was done. To be clear though, I didn't open anything and drop in the dry hop charge. I put them in the dry hop keg and purged it, and then closed transferred in. I know the dry hop keg wasn't 100% purged but I was hoping to minimize O2 that way. I was planning to experiment with transferring sooner(maybe day 3ish) and have built a spunding valve mainly for that purpose. What I'm moving towards is fermenting in a corny and using fermentation CO2 to purge my dry hop keg, which should further limit O2. Probably next batch.

My thoughts on the different variables here I want to test going forward :

-dry hopping with vs without pressure
-transferring into dry hop keg during active fermentation vs when it's done
-transferring into dry hop keg after fermentation is done and after a cold crash to strip as much yeast as possible. I have read theories that dry hop oils get dragged out of beer when the yeast floccs.

Do you have any feedback with any or all of those scenarios what's given you the best results?

 

[VirginiaHops1]

That may be due to the bag being much too constrictive. The beer can't permeate freely to extract the flavor and aroma compounds from the (compacted) hop mass, unless the bag is very roomy and you agitate it periodically. At what temps is that keg being kept?

How did you purge the keg and add the hops? How did you do that, eliminating O2 content and ingress?

I tried to find the biggest hop bag I have but I was concerned with that. I want to devise a way to put the hops in loose and construct a big filter around my dip tube. Until I can figure that out I think next time I'm going to use my big cheap BIAB bag to bag the dry hops and get a nicer one to mash with.

I sealed the keg up with the dry hops and then purged a few times. I know that doesn't 100% eliminate O2, but should get it fairly close.

 

[IslandLizard]

How did you purge the keg and add the hops? How did you do that, eliminating O2 content and ingress?

OK, you answered that while our messages crossed. Not ideal, purging a keg filled with air 'never' reduces O2 content to the needed minimal levels, hence the need for a 100% liquid pre-purge.
You could then stream CO2 in while removing the lid and dropping a CO2 purged bag inside slowly. That would prevent or at least limit O2 ingress greatly.

 

[VirginiaHops1]

OK, you answered that while our messages crossed. Not ideal, purging a keg filled with air 'never' reduces O2 content to the needed minimal levels, hence the need for a 100% liquid pre-purge.
You could then stream CO2 in while removing the lid and dropping a CO2 purged bag inside slowly. That would prevent or at least limit O2 ingress greatly.

Does that really limit O2 that much more than purging a sealed keg? Seems like both would get close to 100% purged but not quite there. But yeah I guess the liquid pre-purge may get it a little closer.

My ideal process as least as I envision is ferment in corny hooked to the dry hop keg to purge with fermentation CO2. Then either water purge the serving keg or daisy chain that one in and have it also purged with fermentation gas. I plan to give that a go next

 

[IslandLizard]

Does that really limit O2 that much more than purging a sealed keg? Seems like both would get close to 100% purged but not quite there.

Big, big difference! There are threads on this forum with graphs and tables showing residual O2 using various methods. The 100% liquid pre-purge is a big step forward, with some attention to small detail you can get that to nearly 100% perfect O2 free. We want to keep the residual DO in beer in the single digit ppb range!

My ideal process as least as I envision is ferment in corny hooked to the dry hop keg to purge with fermentation CO2. Then either water purge the serving keg or daisy chain that one in and have it also purged with fermentation gas. I plan to give that a go next

Something like that would work, but... letting damp hops sit in a vessel being purged for several days with massive amounts of CO2 is not going to do them any favor.

I'm using a lot of CO2 counterflow techniques to keep O2 ingress from happening when working with all beer, not just hoppy ones. I use plastic fermentation buckets (with "airtight" lids) and drilled a 1" access hole in some lids. That makes it easy to take samples, add dry hops, syrups, fruit pulp, etc. as well as allowing me to stir periodically, all while streaming in CO2 through the airlock stem. The back end of long plastic brew spoons have a small paddle, works like a charm.

 

[leesmith]

You could then stream CO2 in while removing the lid and dropping a CO2 purged bag inside slowly. That would prevent or at least limit O2 ingress greatly.

So how would someone CO2 purge the bag of hops?

 

[IslandLizard]

So how would someone CO2 purge the bag of hops?

Sorry, I should have said "flushing" the bag of hops with CO2.

 

[schematix]

I don't liquid purge my kegs anymore as i described in post #1 (although it's still a great and highly effective method). Now I use the fermentation gas to purge a cleaned, sanitized and dried keg.

The liquid purge now comes when i fill the keg with beer. I fill it until beer is flowing out of the (cut dip tube) GAS post. Since the atmosphere inside the keg has been mostly purged by the fermentation gas, there isn't much O2 to come into contact with the beer during that time. Also what little bit of gas does remain is also very low in O2 and spunding will take care of it.

 

[leesmith]

Sorry, I should have said "flushing" the bag of hops with CO2.

Still...is it just a matter of putting the bagged hops in a container....somehow getting a co2 hose in there and then purge...burb...purge...burp for however long....then while running the gas hooked up to keg...open lid of keg...quickly open lid of container with hops and dropping in...close and purge keg?

 

[leesmith]

....I fill it until beer is flowing out of the (cut dip tube) liquid post. Since the atmosphere inside the keg has been mostly purged by the fermentation gas, there isn't much O2 to come into contact with the beer during that time. Also what little bit of gas does remain is also very low in O2 and spunding will take care of it.

So you fill the keg through the gas in post?