Pressurized Closed Loop Corny Keg Fermenting

[cheesebach]

Why not chill it way down and wait for everything to settle? There will be less foam at low temperature, and then you can check your poppet for hop debris. You might be able to blow out any residual debris in the line after that, and then pour clear beer afterwards.

Does your CBDS have the filter screen that's recommended for use when dry hopping?

Thanks for the suggestions - my CBDS does have the filter screen made for dry hopping. I have not yet tried moving the beer out of the keg, so there should be no clogged poppets or debris in the dip tube line yet. I have considered chilling the beer down to serving temps, but I don't have any experience adding dry hops to cold beer, and I'm concerned they might just sink to the bottom immediately and get covered by anything else that settles out at the cold temperatures before they have a chance to break up and get exposure to the beer. This might not be a valid concern, but I don't have any experience with dry hopping cold in a fermenter.

I believe my options at this point are:

1) Keeping beer at current temp of 60F, try to transfer to a purged keg with a screen around the dip tube which dry hops have already been added to. Either add priming sugar to the secondary/serving keg once the beer is transferred to make up for the lost CO2 from my 2 failed attempts to vent the keg, or just use CO2 to force carbonate the rest of the way.
2) Same as #1, but cold crash beer to <40F before transfer. Allow beer to warm back up to get extraction of the dry hops after beer has been transferred.
3) Vent fermenter keg over the next 1-2 days until there is little/no remaining pressure and I'm able to open it without a foam volcano. Add dry hops and priming sugar to re-carbonate the beer and try serving from the fermenter as originally planned.
4) Cold crash the beer in the fermenting keg and try opening the lid and adding dry hops cold. Allow keg to come back up to fementation temps to get dry hop extraction before chilling again and serving from the fermenter as originally planned.

If you guys had to pick, which option seems to be the best for limiting O2 and getting good extraction from the 2nd dose of dry hops?

 

[Veets]

Thanks for the suggestions - my CBDS does have the filter screen made for dry hopping. I have not yet tried moving the beer out of the keg, so there should be no clogged poppets or debris in the dip tube line yet. I have considered chilling the beer down to serving temps, but I don't have any experience adding dry hops to cold beer, and I'm concerned they might just sink to the bottom immediately and get covered by anything else that settles out at the cold temperatures before they have a chance to break up and get exposure to the beer. This might not be a valid concern, but I don't have any experience with dry hopping cold in a fermenter.

I believe my options at this point are:

1) Keeping beer at current temp of 60F, try to transfer to a purged keg with a screen around the dip tube which dry hops have already been added to. Either add priming sugar to the secondary/serving keg once the beer is transferred to make up for the lost CO2 from my 2 failed attempts to vent the keg, or just use CO2 to force carbonate the rest of the way.
2) Same as #1, but cold crash beer to <40F before transfer. Allow beer to warm back up to get extraction of the dry hops after beer has been transferred.
3) Vent fermenter keg over the next 1-2 days until there is little/no remaining pressure and I'm able to open it without a foam volcano. Add dry hops and priming sugar to re-carbonate the beer and try serving from the fermenter as originally planned.
4) Cold crash the beer in the fermenting keg and try opening the lid and adding dry hops cold. Allow keg to come back up to fementation temps to get dry hop extraction before chilling again and serving from the fermenter as originally planned.

If you guys had to pick, which option seems to be the best for limiting O2 and getting good extraction from the 2nd dose of dry hops?

Personally, I'd try #1 if you're going to use priming sugar and #2 if you're going to force carb. You might keep a little more yeast in suspension if you don't cold crash before transfer. But I think they're all pretty reasonable options.

 

[BeerFst]

Just did my first pressure ferment this weekend for a simple blonde with the Voss Kviek yeast and Mandarina Bavaria. That yeast is a beast. Based on the starter i did (just to propagate for another batch later), most of ferm was wrapped up after 8-10 hours. So i let it ride over night in a 90F water bath, then popped the spund on at 30PSI for the next 36 hours or so. I had purchased a graduated cylinder now that i cant just plop the hydrometer in the brew bucket, but of course i broke that on brew day, so i had to use my refractometer. after adjusting for abv, its right at my FG, and 4.5-5%. First sample was very yeasty, even with the janish filter, but its cold crashing now, planning to transfer it to SK tomorrow night.

I did realize last night though that since the beer was at 90F the whole weekend, 30PSI was not actually sufficient carb, but at least its a start. Does anyone know what i should have put my pressure to for 90F? A quick search of the carb tables top out at 65F. I don;'t think i would want to go much beyond 30PSI even with the best yeast, but im curious what volumes i am actually at right now.

Also definitely recommend the yellow gas tape for the spunding valve. I bought the standard amazon PRV and gauge and SS HW from brewers hardware. That thing held pressure perfectly, stuck right at 22PSI for several days when i first tested it.

 

[stickyfinger]

Just did my first pressure ferment this weekend for a simple blonde with the Voss Kviek yeast and Mandarina Bavaria. That yeast is a beast. Based on the starter i did (just to propagate for another batch later), most of ferm was wrapped up after 8-10 hours. So i let it ride over night in a 90F water bath, then popped the spund on at 30PSI for the next 36 hours or so. I had purchased a graduated cylinder now that i cant just plop the hydrometer in the brew bucket, but of course i broke that on brew day, so i had to use my refractometer. after adjusting for abv, its right at my FG, and 4.5-5%. First sample was very yeasty, even with the janish filter, but its cold crashing now, planning to transfer it to SK tomorrow night.

I did realize last night though that since the beer was at 90F the whole weekend, 30PSI was not actually sufficient carb, but at least its a start. Does anyone know what i should have put my pressure to for 90F? A quick search of the carb tables top out at 65F. I don;'t think i would want to go much beyond 30PSI even with the best yeast, but im curious what volumes i am actually at right now.

Also definitely recommend the yellow gas tape for the spunding valve. I bought the standard amazon PRV and gauge and SS HW from brewers hardware. That thing held pressure perfectly, stuck right at 22PSI for several days when i first tested it.

https://www.brewersfriend.com/keg-carbonation-calculator/

 

[BeerFst]

https://www.brewersfriend.com/keg-carbonation-calculator/

thanks, I dont know why i didnt think to check there. That site constantly amazes me, when i used their abv correction for my refractometer I learned about refractometer correction factors...now i have a new thing to start tracking.

 

[cheesebach]

Personally, I'd try #1 if you're going to use priming sugar and #2 if you're going to force carb. You might keep a little more yeast in suspension if you don't cold crash before transfer. But I think they're all pretty reasonable options.

Thanks for the recommendations - I was able to get the beer moved over to the dry hop keg last night using the CBDS without much issue. I sanitized and purged the dry hop keg, then attached CO2 to the liquid out while I opened the lid to add the dry hops. I went slow with the transfer and kept the pressure in both kegs higher than the starting pressure in the fermenting keg to limit CO2 coming out of solution when the beer hit the dry hops in the second keg.

I still don't think I have a good plan that I like for future beers when adding dry hops after naturally carbonating during fermentation. Seems like adding priming sugar to carbonate in the keg at the same time I dry hop might be best, but it's an extra step I'd rather avoid and I'm expecting it would delay getting the keg ready to serve by a few days while I wait for the beer to carbonate using the added sugar.

 

[stickyfinger]

Thanks for the recommendations - I was able to get the beer moved over to the dry hop keg last night using the CBDS without much issue. I sanitized and purged the dry hop keg, then attached CO2 to the liquid out while I opened the lid to add the dry hops. I went slow with the transfer and kept the pressure in both kegs higher than the starting pressure in the fermenting keg to limit CO2 coming out of solution when the beer hit the dry hops in the second keg.

I still don't think I have a good plan that I like for future beers when adding dry hops after naturally carbonating during fermentation. Seems like adding priming sugar to carbonate in the keg at the same time I dry hop might be best, but it's an extra step I'd rather avoid and I'm expecting it would delay getting the keg ready to serve by a few days while I wait for the beer to carbonate using the added sugar.

Why can't you just dry hop in the primary keg with the CBDS when there are a few points left (to carbonate) or dry hop in the primary and add some priming solution then? Then, you can serve from primary or transfer to a purged keg, no need for oxygen exposure. The hop flavor is amazing when you dry hop during primary in the keg and then serve from the keg or transfer to a fermentation-purged keg. so intense and resinous. no need to keg hop from my perspective.

 

[BeerFst]

So I stuck my Voss blonde in the keezer for the last two days. I thought I had put it at 33 but clearly didn’t ao it just sat at my normal 38. After pouring off a bit of a slug of yeast the first samples are very very yeasty tasting, it’s basically bread. The starter and the gravity sample had the same aroma but both obviously had way higher concentrations of yeast. Its not overly sweet so it’s not an attenuation thing but my question is did I just rush the beast yeast and it actually needs to rest at 70 for a bit? It was at 90 per kviek recommendations. Or do I go ahead and transfer to SV and do a proper cold crash? And I guess a better question for this thread would be is this possibly related to the pressure ferment even though it hit terminal?

 

[TimmyWit]

I don't see any reason to rest it at 70. I have pushed all the Omega Kveik strains into the 90's and have been pleased with the results. What did your fermentation schedule look like? I like to give it a few days to clean up after reaching FG. Either that or do a forced diacetyl test to be sure any precursors are gone.

It sounds like you're pulling from the bottom. If you pick up a floating dip tube, you can pressure transfer to a keg with the floating dip tube installed, crash then use that for your SV.

I have not experienced any issues with pressure fermenting the Kveik strains. I have Hothead and Escarpment Labs Hornindal on tap now. They actually got away from me during fermentation, maxed my 60 psi gauges and they're both drinking great (had to bleed them of course).

I feel like Voss has the most farmhouse character of the 3. You'll get a lot of citrus and even a bit of tartness so just a heads up; your final product will probably resemble a saison more than a blonde.

 

[BeerFst]

Brewed Friday night, pitched around 80-85 (lost more heat tranferrring from kettle to keg than expected). Used a swamp cooler with aquarium heater set to 90 on an inkbird. Kept it there until Monday night when I threw it in the keezer to crash.

How do I do a forced diacetyl test? I’ve heard of forced fermentation tests but not specifically for diacetyl.

I’ve thought about getting a cbds, especially after all the mentions on the last couple pages of this thread but SWMBO has put a stop to equipment spending for a bit. I’ve got a 22” straight dip tube in a standard corny with the janish filter so it’s up off the bottom, away from the center. Though not as far up as if I had bent the tube up to the side.

I hear you on 70 being kind of silly, I figured it was better than nothing if the yeast needed to any cleanup, despite that disagreeing with all I have read on the kviek. That said I did take it out of the keezer earlier and put the spund back on just to get an idea of what was going on inside tomorrow. I’ll check in the morning and probably do another, 33f, crash tomorrow night. First crash only went to 38, I was an idiot and didn’t double check I had saved my new set point so it was just hanging out at my standard keezer temp. The extra starter I saved from the Voss did drop nicely at that temp though.

 

[TimmyWit]

Diacetyl test - https://www.winning-homebrew.com/diacetyl-test.html

You definitely want to be sure everything is done if you're going G2G that fast. It can be done with Kveik but there are plenty of variables in play so it's not a slam dunk you can finish in X days. The yeast may need to clean up but they would be better finishing off the job at the 90F+ you had them at initially.

If you already crashed the yeast out, I'm not sure it will do much bringing it back to room temp. It sounds like you're just pulling yeast at the moment so maybe I'm just not sure what you're trying to achieve. If D happens to rear its ugly head after you crash, the yeast will likely need something to chew on before they can clean it up. Nobody wants to wake up just to clean but if there's a hearty meal waiting on them, they're more likely to roll out of bed and get moving

What do you disagree with about Kveik? I have used it quite a bit over the past year+ and I have not been disappointed.

You are likely good to go and I look forward to hearing your thoughts on this brew.

 

[stickyfinger]

Brewed Friday night, pitched around 80-85 (lost more heat tranferrring from kettle to keg than expected). Used a swamp cooler with aquarium heater set to 90 on an inkbird. Kept it there until Monday night when I threw it in the keezer to crash.

How do I do a forced diacetyl test? I’ve heard of forced fermentation tests but not specifically for diacetyl.

I’ve thought about getting a cbds, especially after all the mentions on the last couple pages of this thread but SWMBO has put a stop to equipment spending for a bit. I’ve got a 22” straight dip tube in a standard corny with the janish filter so it’s up off the bottom, away from the center. Though not as far up as if I had bent the tube up to the side.

I hear you on 70 being kind of silly, I figured it was better than nothing if the yeast needed to any cleanup, despite that disagreeing with all I have read on the kviek. That said I did take it out of the keezer earlier and put the spund back on just to get an idea of what was going on inside tomorrow. I’ll check in the morning and probably do another, 33f, crash tomorrow night. First crash only went to 38, I was an idiot and didn’t double check I had saved my new set point so it was just hanging out at my standard keezer temp. The extra starter I saved from the Voss did drop nicely at that temp though.

have you tried replacing your SWMBO? some have reported better brewing results

 

[Veets]

I still don't think I have a good plan that I like for future beers when adding dry hops after naturally carbonating during fermentation. Seems like adding priming sugar to carbonate in the keg at the same time I dry hop might be best, but it's an extra step I'd rather avoid and I'm expecting it would delay getting the keg ready to serve by a few days while I wait for the beer to carbonate using the added sugar.

Consider getting a second CBDS for your serving keg, and putting your dry hops in the serving keg prior to transfer. Then you can do a pressurized, closed-loop transfer from fermenter keg to serving keg, and not worry about O2 or having to use priming sugar.
I've got an American IPA in the fermenter right now, which I brewed last Friday and have been using to purge a serving keg with a spunding valve on it. I kept it at 10psi during primary, and yesterday allowed it to come up to 30psi for natural carbonation. Next step will be do to a pressurized, closed-loop transfer to the purged serving keg (which already has an extra charge of Amarillo hop pellets in it), then chill it down after letting the hop oils dissolve.

 

[stickyfinger]

Consider getting a second CBDS for your serving keg, and putting your dry hops in the serving keg prior to transfer. Then you can do a pressurized, closed-loop transfer from fermenter keg to serving keg, and not worry about O2 or having to use priming sugar.
I've got an American IPA in the fermenter right now, which I brewed last Friday and have been using to purge a serving keg with a spunding valve on it. I kept it at 10psi during primary, and yesterday allowed it to come up to 30psi for natural carbonation. Next step will be do to a pressurized, closed-loop transfer to the purged serving keg (which already has an extra charge of Amarillo hop pellets in it), then chill it down after letting the hop oils dissolve.

so you put the amarillo into the sanitized SK before you hooked up the FK and spunding valve in the SK? that could work well

 

[BeerFst]

Diacetyl test - https://www.winning-homebrew.com/diacetyl-test.html

What do you disagree with about Kveik? I have used it quite a bit over the past year+ and I have not been disappointed.

I just meant that everything I had read had supported extremely fast grain to glass, and that i may not need to let it clean up really, despite my better judgemtn. So it wasnt so much disagreeing with you specifically, just the general public.

I agree that 90 would have been better, but since i had broken down my swamp heater and it was already 11, i just said forget it and stuck it at room temp. I was just thinking that since i didnt check FG more than once that maybe there was some remaining extract that needed to be converted. I figured that if i was pulling a ton of yeast that maybe there was enough in solution to still clean things up, but i get that that is probably wrong.

I'll do the precursor test tonight (way easier than i had expected it to be) and if i do get it to be buttery, ill toss in some dextrose, get it back to 90F and let her clean up. I was still short .5 volumes of carb from the initial spund, so other than waiting a bit more time, it will only benefit.

The saison nature could be interesting. I'm not a huge fan of a classic super flowery saison (though i did just have trillium free rise for the first time and it was great), but I do like the new style, sourish kind, so if this is what you are describing i am in. I'm hoping that its just the yeast in solution that is covering up the mandarina cause right now im not really getting anything from the hop stand. worst case i can "carefully" SK Keg hop it to get some more character, though i rather not have to mess with that

 

[stickyfinger]

I'll do the precursor test tonight (way easier than i had expected it to be) and if i do get it to be buttery, ill toss in some dextrose, get it back to 90F and let her clean up. I was still short .5 volumes of carb from the initial spund, so other than waiting a bit more time, it will only benefit.

i went through a long period of diacetyl problems and did tons of diacetyl precursor tests. I found that unless I used certain yeast strains, I almost always had precursors in my hoppy beers. It's very hard to avoid precursors in hoppy beers for some reason (perhaps the hop creep effect.) Now that I stopped cold crashing in carboys, I haven't had any diacetyl issues and stopped doing the test. It never hurts to do the test though just to see if there are precursors and then see whether the keg develops diacetyl if you do detect precursors.

 

[TimmyWit]

I just meant that everything I had read had supported extremely fast grain to glass, and that i may not need to let it clean up really, despite my better judgemtn. So it wasnt so much disagreeing with you specifically, just the general public.

I'll do the precursor test tonight (way easier than i had expected it to be) and if i do get it to be buttery, ill toss in some dextrose, get it back to 90F and let her clean up. I was still short .5 volumes of carb from the initial spund, so other than waiting a bit more time, it will only benefit.

The saison nature could be interesting. I'm not a huge fan of a classic super flowery saison (though i did just have trillium free rise for the first time and it was great), but I do like the new style, sourish kind, so if this is what you are describing i am in. I'm hoping that its just the yeast in solution that is covering up the mandarina cause right now im not really getting anything from the hop stand. worst case i can "carefully" SK Keg hop it to get some more character, though i rather not have to mess with that

Oh, it can clean-up AND be done quick. I pitched Hornindal and Voss on top of cakes from a previous batch and they fermented from 1.063 to 1.010 in a day. I caught it just in time to get the dry hop in there (17 hrs in @ 1.017). I gave them a few days to clean up, did a diacetyl test on day 3, then crashed on day 4. With spunding, I was drinking a perfectly carbed beer 5 days after brew day. Still, to go that fast, you'd need a very large healthy pitch, aeration, and high temps.

This last brew day I almost forgot who I was messing with. I left the kegs at room temp after pitching while waiting for my ferm chamber to come to temps. I came back to put the spunding valve on 2 hours later and was already at 50 psi.

Diacetyl isn't perceived as buttery to everyone. I had to learn what it was and really think about it to see how you could pull butter from that aroma. But, with the test you are doing, if one smells different than the other, you'll learn what diacetyl smells like to you.

It won't come across as super sour; just a mild tartness that goes pretty well with the citrus

 

[BeerFst]

So do you follow normal ale pitch rates with them? Lars had suggested a tsp of slurry per 25l which I thought was insane. I have read anecdotes and articles on the actual Norwegians using similar amounts of dried but it was still too little for me to you with. I did still underpitch but to the tune of 100b where the 4.5gallons of 1.049 required 180b (I think), as calculated on brewers friend

 

[TimmyWit]

I follow my normal ale pitching rates which means building a larger than necessary starter. I have never experienced an off-flavor from over-pitching so my rationale is to account for lower than expected viability.

The batch that finished in a day would have been a very large pitching rate since it was pitched on a yeast cake. With that in mind, it was basically a decanted 4 gallon starter. Still, I did not experience any negative effects; just a super fast ferment.

I know some folks like to intentionally underpitch to encourage ester formation. I think Lars is just suggesting to replicate what the Norwegian farmers are doing. But, they're also drinking the stuff warm and flat a few days after brewing.

 

[stickyfinger]

Oh, it can clean-up AND be done quick. I pitched Hornindal and Voss on top of cakes from a previous batch and they fermented from 1.063 to 1.010 in a day. I caught it just in time to get the dry hop in there (17 hrs in @ 1.017). I gave them a few days to clean up, did a diacetyl test on day 3, then crashed on day 4. With spunding, I was drinking a perfectly carbed beer 5 days after brew day. Still, to go that fast, you'd need a very large healthy pitch, aeration, and high temps.

This last brew day I almost forgot who I was messing with. I left the kegs at room temp after pitching while waiting for my ferm chamber to come to temps. I came back to put the spunding valve on 2 hours later and was already at 50 psi.

Diacetyl isn't perceived as buttery to everyone. I had to learn what it was and really think about it to see how you could pull butter from that aroma. But, with the test you are doing, if one smells different than the other, you'll learn what diacetyl smells like to you.

It won't come across as super sour; just a mild tartness that goes pretty well with the citrus

diacetyl smells like butterscotch to me. it’s DISGUSTING in ipa

 

[BeerFst]

diacetyl smells like butterscotch to me. it’s DISGUSTING in ipa

I can't say that i have recognized it recently. but i distinctly remember HATING brooklyn lager in college because it tasted like drinking butter to me. it was many years later when i started homebrewing and read about diacetyl that it dawned on me that could have been the problem. I've also had it since then and not had the same problem...so I suppose it could have actually been dirty draft lines.

 

[cheesebach]

Why can't you just dry hop in the primary keg with the CBDS when there are a few points left (to carbonate) or dry hop in the primary and add some priming solution then? Then, you can serve from primary or transfer to a purged keg, no need for oxygen exposure. The hop flavor is amazing when you dry hop during primary in the keg and then serve from the keg or transfer to a fermentation-purged keg. so intense and resinous. no need to keg hop from my perspective.

Thanks for the input - I'm sure that approach works well and gives good results, but there's a few considerations I've kicked around in my head which make me question whether they'll produce the result I'm looking for, depending on the beer:

1) Dry hopping with a few points left (an amount sufficient to fully carbonate the beer): This seems like this would fall roughly at the same time that I'm introducing my first dry hop in a NEIPA. I'm guessing that by the time I start to notice fermentation slowing and go to add my 1st dry hop in this style, the beer is probably 70% or more of the way through fermentation. If I do my 1st dry hop here and a 2nd when the beer just enough sugars left to fully carbonate, I'm guessing the difference is maybe a few hours. To be clear, I haven't done side-by-side experiments yet comparing a single dry hop with twice the amount of hops during active fermentation vs. a fermentation + a post-fermentation dry hop, but it's a variable that I've been intending on exploring, so I need a good way to add dry hops post-fermentation while keeping O2 to a minimum to do a proper comparison.
2) What is the impact to hop character and clarity from dry hopping at the tail end of fermentation vs. after the yeast has settled out? Would this bring out the hop character that I'm looking for in something like a PtE-type recipe with 2 big dry hop additions (both after fermentation), or would it result in more haze and "juicy" character from the hops through the yeast/hops interactions? Again, something that I've been wanting to test on a west-coast style beer, but still a consideration for me.
3) In general, I've tended to avoid using priming sugar after fermentation, since I want to avoid waking the yeast up and having to wait the extra time for the beer to carbonate and the yeast to clean up again. For those who've added priming sugar to a fully fermented keg - how long do you typically need to wait for the beer to fully carb and be ready to start crash cooling prepare for serving? Seems like bottles require sometimes 2 weeks (even at room temps, which may be higher than fermentation temps). Can a primed keg be fully complete at 3 or 4 days after priming?
4) If I prime at the same time or after a post-fermentation dry hop, does it then become more similar to a active fermentation dry-hop? Does some of the hop flavor drop out with the yeast that gets woken up for the priming sugar snack?

I'm sure that I'm over-thinking this and one or more of these concerns may be non-issues, but I just wanted to share some of my thoughts/concerns on this. I have a NEIPA going that I'll soon be crash cooling and getting ready to tap in about 5 days, which had a fermentation dry hop at around 60 hours in and natural carbing during end of fermentation. I transferred this to a water purged keg which I opened/closed quickly to add a second dry hop to while pushing CO2 in through the liquid out. I plan to serve directly from this keg, and if it goes well, this may become my standard practice for this style until I get a chance to run some controlled experiments testing some of these things.

 

[stickyfinger]

I can't say that i have recognized it recently. but i distinctly remember HATING brooklyn lager in college because it tasted like drinking butter to me. it was many years later when i started homebrewing and read about diacetyl that it dawned on me that could have been the problem. I've also had it since then and not had the same problem...so I suppose it could have actually been dirty draft lines.

or maybe it was just that Brooklyn Lager is a pretty mediocre beer (IMHO). ha ha. sorry if you love Brooklyn Lager, hipsters of the world.

 

[stickyfinger]

Thanks for the input - I'm sure that approach works well and gives good results, but there's a few considerations I've kicked around in my head which make me question whether they'll produce the result I'm looking for, depending on the beer:

1) Dry hopping with a few points left (an amount sufficient to fully carbonate the beer): This seems like this would fall roughly at the same time that I'm introducing my first dry hop in a NEIPA. I'm guessing that by the time I start to notice fermentation slowing and go to add my 1st dry hop in this style, the beer is probably 70% or more of the way through fermentation. If I do my 1st dry hop here and a 2nd when the beer just enough sugars left to fully carbonate, I'm guessing the difference is maybe a few hours. To be clear, I haven't done side-by-side experiments yet comparing a single dry hop with twice the amount of hops during active fermentation vs. a fermentation + a post-fermentation dry hop, but it's a variable that I've been intending on exploring, so I need a good way to add dry hops post-fermentation while keeping O2 to a minimum to do a proper comparison.
2) What is the impact to hop character and clarity from dry hopping at the tail end of fermentation vs. after the yeast has settled out? Would this bring out the hop character that I'm looking for in something like a PtE-type recipe with 2 big dry hop additions (both after fermentation), or would it result in more haze and "juicy" character from the hops through the yeast/hops interactions? Again, something that I've been wanting to test on a west-coast style beer, but still a consideration for me.
3) In general, I've tended to avoid using priming sugar after fermentation, since I want to avoid waking the yeast up and having to wait the extra time for the beer to carbonate and the yeast to clean up again. For those who've added priming sugar to a fully fermented keg - how long do you typically need to wait for the beer to fully carb and be ready to start crash cooling prepare for serving? Seems like bottles require sometimes 2 weeks (even at room temps, which may be higher than fermentation temps). Can a primed keg be fully complete at 3 or 4 days after priming?
4) If I prime at the same time or after a post-fermentation dry hop, does it then become more similar to a active fermentation dry-hop? Does some of the hop flavor drop out with the yeast that gets woken up for the priming sugar snack?

I'm sure that I'm over-thinking this and one or more of these concerns may be non-issues, but I just wanted to share some of my thoughts/concerns on this. I have a NEIPA going that I'll soon be crash cooling and getting ready to tap in about 5 days, which had a fermentation dry hop at around 60 hours in and natural carbing during end of fermentation. I transferred this to a water purged keg which I opened/closed quickly to add a second dry hop to while pushing CO2 in through the liquid out. I plan to serve directly from this keg, and if it goes well, this may become my standard practice for this style until I get a chance to run some controlled experiments testing some of these things.

I'd be interested in hearing the results of your experimentation. I can't answer most of your questions. I think 4-5 days is probably a minimum for carbonating after adding the sugar. I just did an IPA this way and waited 5 days after adding the sugar before the pressure stabilized. I'd say adding hops at the same time as priming sugar is pretty much identical to adding them early on in fermentation and then racking to a keg to carbonate. It's just active yeast in suspension converting some compounds to some others that taste amazing!

I'd be interested in trying adding some pellet hops to a sanitized keg and then letting that keg purge with CO2 over the entire fermentation. Then, closed transfer onto the hops. Yeah, you will lose some character from the CO2 purge I'm sure, but you will have very little O2 exposure, and you will probably get that post fermentation "keg hop" flavor if you are after that.

 

[cheesebach]

Consider getting a second CBDS for your serving keg, and putting your dry hops in the serving keg prior to transfer. Then you can do a pressurized, closed-loop transfer from fermenter keg to serving keg, and not worry about O2 or having to use priming sugar.
I've got an American IPA in the fermenter right now, which I brewed last Friday and have been using to purge a serving keg with a spunding valve on it. I kept it at 10psi during primary, and yesterday allowed it to come up to 30psi for natural carbonation. Next step will be do to a pressurized, closed-loop transfer to the purged serving keg (which already has an extra charge of Amarillo hop pellets in it), then chill it down after letting the hop oils dissolve.

This is pretty similar to what I ended up doing for my current batch, but I used the Janish dip tube screen in the serving keg instead of a CBDS. Do you have any dry hops added in your fermentation keg, or only the serving keg? With dry hops in fermentation, I'd be concerned about clogging the CBDS on the serving keg side if you have the dry hop screen on, even with a screen on the fermentation side - there's not much surface area there if small particles do make it through the first screen and get stuck in the second.

Also, are you water purging your serving keg with the CBDS before hooking up to your fermenter to purge during fermentation? How do you make sure to get all the water/santizer out with the CBDS? Seems like you'd have to invert the keg and push it out through the gas in, which would be kind of awkward with the CBDS in there.

 

[cheesebach]

I'd be interested in trying adding some pellet hops to a sanitized keg and then letting that keg purge with CO2 over the entire fermentation. Then, closed transfer onto the hops. Yeah, you will lose some character from the CO2 purge I'm sure, but you will have very little O2 exposure, and you will probably get that post fermentation "keg hop" flavor if you are after that.

I'm guessing you'd want to fully purge the serving keg if you do that? Otherwise, the hops in that keg will see a lot of O2 while they're sitting at fermentation temps waiting for the fermentation gasses to reduce the O2 concentration in the serving keg.

Next time I do dry hops in the serving keg (if I decide I like it after this batch), I'll probably use fermentation to purge the keg and add the hops to it when I get closer to transfer time. Hopefully, not too much O2 would get in if you worked quick and purged from the bottom with CO2 from a tank while you had it open. You'd end up with probably a bit more O2 in the system overall this way, but for some reason, the thought of leaving hops in an empty keg at room temps for days scares me...

 

[stickyfinger]

I'm guessing you'd want to fully purge the serving keg if you do that? Otherwise, the hops in that keg will see a lot of O2 while they're sitting at fermentation temps waiting for the fermentation gasses to reduce the O2 concentration in the serving keg.

Next time I do dry hops in the serving keg (if I decide I like it after this batch), I'll probably use fermentation to purge the keg and add the hops to it when I get closer to transfer time. Hopefully, not too much O2 would get in if you worked quick and purged from the bottom with CO2 from a tank while you had it open. You'd end up with probably a bit more O2 in the system overall this way, but for some reason, the thought of leaving hops in an empty keg at room temps for days scares me...

yeah, maybe that IS a dumb idea. I think I like the idea of adding the hops afterward as you suggested in retrospect. it might be worth a try though. if you apply CO2 pressure to the keg as you add the hops to the SK (as you said), it should be pretty good. if you keep the keg warm for a few days, the yeast might take up some of the oxygen; i don't know. i always assumed yeast could take up oxygen even if they weren't really in active fermentation, but that might be BS.

 

[Veets]

Do you have any dry hops added in your fermentation keg, or only the serving keg? With dry hops in fermentation, I'd be concerned about clogging the CBDS on the serving keg side if you have the dry hop screen on, even with a screen on the fermentation side - there's not much surface area there if small particles do make it through the first screen and get stuck in the second.

Yes - one ounce of Amarillo when filling the keg, just prior to pitching. I've done it this way before, with no clog. I'm counting on the idea that they've been in there long enough that they've settled down to the bottom.

Also, I have one CBDS but also made a few of these:

http://think.gusius.com/diy-keg-floating-dip-tube

The DIY-type has a large filter at the inlet - much bigger than the pickup tube hole in the CBDS. It's possible that it's been helping. I generally don't pay attention to whether the CBDS is in the fermenter or serving keg - I regard them as equivalent. But I've probably done only a half-dozen batches fermenting in the keg with a floating dip tube, so maybe one time I'll get a clog.

Also, are you water purging your serving keg with the CBDS before hooking up to your fermenter to purge during fermentation? How do you make sure to get all the water/santizer out with the CBDS? Seems like you'd have to invert the keg and push it out through the gas in, which would be kind of awkward with the CBDS in there.

No, I don't water-purge. I sanitize (star-san), and then drain it all out by tipping. after fermentation is underway, I'll get the last ounce of star-san with a clean towel, drop in the hop pellets, and then hook it up to the fermenter so CO2 from fermentation is purging the keg (spunding valve on the gas side of the serving keg - CO2 from fermenter being put in via the liquid side). I've read elsewhere that the amount of CO2 generated from fermenting a 5 gallon batch is tremendous, and more than enough to flush O2 out of a serving keg. I'm relying on that idea.

 

[cheesebach]

No, I don't water-purge. I sanitize (star-san), and then drain it all out by tipping. after fermentation is underway, I'll get the last ounce of star-san with a clean towel, drop in the hop pellets, and then hook it up to the fermenter so CO2 from fermentation is purging the keg (spunding valve on the gas side of the serving keg - CO2 from fermenter being put in via the liquid side). I've read elsewhere that the amount of CO2 generated from fermenting a 5 gallon batch is tremendous, and more than enough to flush O2 out of a serving keg. I'm relying on that idea.

So you’re tossing pellet hops in loose into an empty keg that hasn’t been purged and just relying on fermentation CO2 to purge the O2 from the keg? I’ve never tried this, so I don’t have any data to say this would be a problem, but intuitively, exposing hops to a keg full of ambient air at fermentation temps would seem like it might oxidize the hops before the fermentation can purge all the O2 from the keg. If you haven’t noticed any negative effects, maybe it’s not as much of a concern as I would have guessed. Good to know and maybe gives me a few more options to consider, thanks!

 

[BeerFst]

or maybe it was just that Brooklyn Lager is a pretty mediocre beer (IMHO). ha ha. sorry if you love Brooklyn Lager, hipsters of the world.

Ha, well college wasn’t really a time of discerning palates...keystone was the norm and coors was the fancy version. I was drinking a decent amount of craft but this was really early on in my trials. Luckily the finger lakes had plenty of options and a few bars ahead of their time with rotating tap lists. For everything I didn’t like though (iPas included at the time) , Brooklyn lager really stood out as being extra terrible. More recently haven’t noticed the butter in it but probably only had one or two in the last several years.

On actual homebrew news, I didn’t detect any diacetyl, the warmed Beer just smelled extra yeasty, and like warm beer... so I restarted the cold crash at a proper 33 this time. The colder sample also started to show some of the nice citrus notes I was hoping for too. I should have just HAHB but that last keg just kicked a few days ago