Dry hopping in serving keg

[AlexKay]

Another datum: I brewed a graf in September with no hops, save for a significant dry hop with Saaz at packaging. It’s been sitting for 3+ months on those hops, at serving temperature. All of the hop-derived flavor is great, with nothing vegetal that I can notice even after this amount of time.

It has picked up some bitterness, however, which I find surprising. Presumably from non-alpha-acid sources, but it’s definitely there (and not unwelcome, at that.)

 

[OzzyPeeps]

Yeah I'm aware of the method ...

I just figure blowing gas through the keg for 3 days can't possibly be doing any favors for the volatile aromatic terpenoids we are in the business of trying to keep in the beer ...

Kind of feels like it just defeats the purpose a bit..

You wouldn't leave hops out on the counter for 3 days - and that's not just because of oxidation.

Many terpenes are volatile alcohols that "boil off" at room temp.

I'm not hating on anyone's methods, it just that the subject is an obsession of mine and a perfectionist

 

[OzzyPeeps]

So my plan is to build a hop Randal system using the kegland 2" Hop Bong.

Nothing revolutionary there, that's one of it's intended purposes - to be used in-line under gas pressure on a one way trip to a another keg or a glass.

What I want to do is use it instead with a pump to pull/push finished (but uncarbonated) beer in a loop from the corny keg it is in, out the liquid dip tube, through the hops in the bong, and back into the same keg through the gas in tube.

Basically dry hopping "in keg" without the hops actually being in the keg.

Obviously lines and bong would be pre- flushed with CO2 and pump, bong and lines primed with beer using gas pressure, then close loop and run pump for X amount of time.

The advantages would be to numerous to enumerate.

Got myself a kegland super sucker siphon pump (same as the northern brewer one) which should have no trouble with the duty cycle...

The only thing I'm a bit worried about is the constriction of flow at the qds/poppets - there will be 4 in the loop -

Don't want to burn out the pump - but it does crazy high pressure so probably be ok

 

[OzzyPeeps]

Does anyone know what the actual effective aperture diameter at the poppet around the pin of the QD is?

Or does anyone have any experience using that kind of pump to push through multiple qds?

An I over thinking it?

I don't know much about pumps but it seems to be a beast

 

[AlexKay]

Does anyone know what the actual effective aperture diameter at the poppet around the pin of the QD is?

Or does anyone have any experience using that kind of pump to push through multiple qds?

An I over thinking it?

I don't know much about pumps but it seems to be a beast

It seems to be a diaphragm pump, which is what you want here: it can deliver pressure and won’t self-destruct if it cavitates or deadheads. I use a diaphragm pump (not that one) to clean beer lines, through a liquid post, QD, up to 20’ of EVA tubing, and a faucet. It never seems to struggle, but it does get hot running for 15+ minutes.

Heat is what I’d watch out for when you’re implementing your idea. You’re probably not even approaching the heat input from a pasteurizer, and hoppy commercial beers can more or less survive that, but if you’re trying to eliminate every theoretical risk to flavor, heating up the beer definitely is a source of damage.

 

[OzzyPeeps]

It seems to be a diaphragm pump, which is what you want here: it can deliver pressure and won’t self-destruct if it cavitates or deadheads. I use a diaphragm pump (not that one) to clean beer lines, through a liquid post, QD, up to 20’ of EVA tubing, and a faucet. It never seems to struggle, but it does get hot running for 15+ minutes.

Heat is what I’d watch out for when you’re implementing your idea. You’re probably not even approaching the heat input from a pasteurizer, and hoppy commercial beers can more or less survive that, but if you’re trying to eliminate every theoretical risk to flavor, heating up the beer definitely is a source of damage.

Thanks, that's really helpful ... If a little deflating ... I was planning to run it constantly for the whole usual 72 hour dry hop ... Guess that was a dumb idea...

Is there any pump that would be up to that?

Maybe if I run it on a timer 5 min on 5 min off or something ...

In any case, to un-derail the thread I will be reverting to popping the good and dropping in a hop tube until experiments with pump and bong are concluded

 

[BongoYodeler]

While not an inexpensive solution this worked very well for me on an ipa I kegged a week ago. The pic below was taken during a test using several year old hops. A 2-inch hop bong, I didn't bother attaching the gas post or the top which has a prv. The test was just to see how well the hop pellets dropped into the keg, which they did just fine.

When I used it for real, I should have taken a picture, but this is what I did. My Speidel 30L fermenter has the NorCal O2-free transfer kit installed. It has a blowoff, gas-in QD, and liquid-out QD. So I had the blowoff going to the liquid-out of a dry hop keg (hop bong attached), out through the gas-in port and over to a serving keg liquid-out, and then out through the gas-in port into a blowoff jar of StarSan. Fermentation purged both kegs. After fermentation I cold crashed to 48° for couple days and did a closed transfer to the dry hop keg. I allowed the temperature to rise to 58° and attached my CO tank to the bong and purged, then dropped 4.5 oz of pellets. Repeated with 4 mor oz of pellets. Worked like a charm. After 2 or 3 days I cold crashed to 50° and pressure-transferred to the serving keg.

 

[Broken Crow]

I was planning to run it constantly for the whole usual 72 hour dry hop ...

Though I haven't tried it yet, I have the same spec pump and have been contemplating the same configuration though I never intended to pump that long. I suppose it depends on wether you're using pellets or whole hops... My assumption was that with pellets, they'd all dissolve and end up in the keg after about 5-10 minutes of circulation at which point I'd switch to gas to purge the hop bong dry. I routinely use my racking pump for kegging and though it does get slightly warm after 3 kegs, it never gets hot... The greatest length of time I've ever run it was when I was using it with a Quick-Carb stone/tee and it would take about 45 minutes to carb a keg. It got warmer then, but not hot, nevertheless I really wouldn't want to task it with a 72 hour run as I would worry about that much stress ripping the diaphram or even burning out the motor as it is after all; built to a price-point.
Just my 2-cents.

 

[OzzyPeeps]

Though I haven't tried it yet, I have the same spec pump and have been contemplating the same configuration though I never intended to pump that long. I suppose it depends on wether you're using pellets or whole hops... My assumption was that with pellets, they'd all dissolve and end up in the keg after about 5-10 minutes of circulation at which point I'd switch to gas to purge the hop bong dry. I routinely use my racking pump for kegging and though it does get slightly warm after 3 kegs, it never gets hot... The greatest length of time I've ever run it was when I was using it with a Quick-Carb stone/tee and it would take about 45 minutes to carb a keg. It got warmer then, but not hot, nevertheless I really wouldn't want to task it with a 72 hour run as I would worry about that much stress ripping the diaphram or even burning out the motor as it is after all; built to a price-point.
Just my 2-cents.

I've made hop teas with pellets at 65c ... They go to mush, mush goes into a French press style caffetiere and I put all my weight on the plunger to get max utilization out of them and squeeze everything out

The standard mesh on those things keeps almost all the mush in the press - and it's not that fine a mesh.

Using the appropriate mesh size in the bong, no chance they end up in the keg.

Every mesh size under the sun to fit the bong from ali express

A clog maybe. But two stage filtration would fix that

At the end of the day it's designed to be a Randal for pellets - if they disolved and passed through the screen we would know by now

And I'm pretty sure Kee does plenty of testing before he releases a product so I really wouldnt anticipate that being a problem

Possibly much less time would be needed as theoretically utilization should be very high

Nice to know someone else has been thinking a long the same lines.

If it can be made to work it would save all the faf and expense (and locking up of kegs) in BongoYodeler's method

Not to mention all the extra arse ache of cleaning the spent loose hops out of the serving keg when it kicks, which honestly is my number one reason for pursuing the idea.

Not a fan of the grind of cleaning at the best of times and the green mush is the worst

It moulded up on me the last time as I couldn't get round to cleaning it

That's a real "f**k my life moment"

 

[OzzyPeeps]

Though I haven't tried it yet, I have the same spec pump and have been contemplating the same configuration though I never intended to pump that long. I suppose it depends on wether you're using pellets or whole hops... My assumption was that with pellets, they'd all dissolve and end up in the keg after about 5-10 minutes of circulation at which point I'd switch to gas to purge the hop bong dry. I routinely use my racking pump for kegging and though it does get slightly warm after 3 kegs, it never gets hot... The greatest length of time I've ever run it was when I was using it with a Quick-Carb stone/tee and it would take about 45 minutes to carb a keg. It got warmer then, but not hot, nevertheless I really wouldn't want to task it with a 72 hour run as I would worry about that much stress ripping the diaphram or even burning out the motor as it is after all; built to a price-point.
Just my 2-cents.

Spec says the pump does over 4/ 1gal a minute

So I guess if you recirc for 5 min on a timer and then give it some down time all the beer in the keg has been through the hops

I theorize much better utilization through the "squeezing"/plunger effect, so maybe a day of 5 min on 5 min off would do it

Time and experimentation will tell (I have yet to buy the bong and screens and bits.) there's some festival or something on in China so they don't ship till Feb 6 + shipping time from China

Another reason this has been in my mind is the best hop taste and aroma I ever experienced was with a basic bitch bucket and a hop sick in primary

When it was done I just reached in with sani'd gloves and squeezed it like it owed me money

It smelled it and tasted it and ended up drinking a couple of pints right out of the fermenter is was so good

So much flavour and aroma is lost by hop absorption

Someone needs to make some sort of magnetic device that squeezes them between screens in fermenter or keg to wring em out

 

[BongoYodeler]

of kegs) in BongoYodeler's method

Not to mention all the extra arse ache of cleaning the spent loose hops out of the serving keg when it kicks, which honestly is my number one reason for pursuing the idea.

Not a fan of the grind of cleaning at the best of times and the green mush is the worst

It moulded up on me the last time as I couldn't get round to cleaning it

That's a real "f**k my life moment"

Never understood this. The key is to take the time to clean right after emptying the keg, be it dry hop keg or serving keg. A few days ago, within an hour of transferring the beer from the dh keg to the serving keg I filled the empty dh keg, which had nearly 8.5 oz of commando hop debris, about 1/3 full with 130°f water closed it up and gave it a good shake then emptied it. This removed probably 95% of the hop matter. I then repeated the process and that got the rest. After that I fill the keg a little more than half way with 130° water mixed with a half scoop of Oxiclean and soaked upright, then upside down for a couple hours each. Rinsed well then StarSan rinse. Done. I do the same with the serving keg.
*I remove and clean the dip tubes separately.

 

[OzzyPeeps]

I clean non dh'd kegs with a quick blast with a pressure washer, same for the dip, then down the slop sink in my brew room. Takes seconds it's just a bit of yeast

I can't empty 5 oz hop mush down the sink - 150yr old house, no macerator in the sink like some have in 'merica

Drains are old and Dodgey so can't go down a toilet (which would mean climbing a flight of stairs anyway - and then my floating do tube ends up dangling into my toilet ...)

Or I could descend 2 flights of stairs and go outside, but I'm in Ireland and it's pissing rain 90 pc of the time

Plus I have a cat I love more than I've ever loved a human and hops are toxic to cats but he likes the smell of them so I'm paranoid about debris ...

Everyone's setup is different but putting all that aside, my number one goal with brewing these days is to simplify the process and reduce as many unnecessary steps as I can

I've considered your method but I'm too stingy to waste the CO2 (half Scottish) and I don't have the free kegs

A hop tube mesh works ok for my situation but means popping the hood

I've lusted for one of those triclamp port keg lids but then the damn keg wouldn't fit in my diy kegerator

Plus ... Something inside just tells me the pump recirc Randal is gonna be the WAY.

Might need 2 pumps , one either side of the bong ...

Edit to add ... FURTHERMORE , though I know this could be shocking to many on a beer forum, I like to get loaded and "tie one on" as you folks say which according To Murphys law is when the keg decides to kick ... and cleaning kegs at 4am when I've had one too many is just not part of my program brother

 

[Deadalus]

So my plan is to build a hop Randal system using the kegland 2" Hop Bong.

Nothing revolutionary there, that's one of it's intended purposes - to be used in-line under gas pressure on a one way trip to a another keg or a glass.

What I want to do is use it instead with a pump to pull/push finished (but uncarbonated) beer in a loop from the corny keg it is in, out the liquid dip tube, through the hops in the bong, and back into the same keg through the gas in tube.

Basically dry hopping "in keg" without the hops actually being in the keg.

Obviously lines and bong would be pre- flushed with CO2 and pump, bong and lines primed with beer using gas pressure, then close loop and run pump for X amount of time.

The advantages would be to numerous to enumerate.

Got myself a kegland super sucker siphon pump (same as the northern brewer one) which should have no trouble with the duty cycle...

The only thing I'm a bit worried about is the constriction of flow at the qds/poppets - there will be 4 in the loop -

Don't want to burn out the pump - but it does crazy high pressure so probably be ok

If concerned about the poppets, a tee could potentiallly be used. Consider a 1/2" Tee and label the ports as 3, 6, 9 o'clock. The 6 o'cclck port gets a keg post x 1/2" NPT adapter, 3 o'clock gets a 1/2" inline valve, and 9 o'clock gets a bushing to thread into the keg, depends on keg manufacturer. After the valve gets a regular 1/2" QD or camlock. Use the valve and its QD to pump and the keg QD to serve. Replicating it 4x may not be completely necessary, although I'd have to think about the hop bong end a little more.

 

[OzzyPeeps]

If concerned about the poppets, a tee could potentiallly be used. Consider a 1/2" Tee and label the ports as 3, 6, 9 o'clock. The 6 o'cclck port gets a keg post x 1/2" NPT adapter, 3 o'clock gets a 1/2" inline valve, and 9 o'clock gets a bushing to thread into the keg, depends on keg manufacturer. After the valve gets a regular 1/2" QD or camlock. Use the valve and its QD to pump and the keg QD to serve. Replicating it 4x may not be completely necessary, although I'd have to think about the hop bong end a little more.

Very interesting. Im not familiar with all of those fittings but I understand the concept and it has never occurred to me

I was going to go with the standard pco bottle end caps either side of the bong like this

https://kegland.com.au/products/pco1881-male-x-2-inch-tri-clover-pok?variant=43494948045056

That take carb cap qds ... But they attach with a triclamp so i guess you could go anywhere after that and choose you're valve or fittings

Very very interesting, thank you.

Common sense as soon as someone else explains it to me, ha.

Not expensive mods, could do all four duty kegs and presumably it opens up the project to more or pump diameters ... Anything that could handle the dip tube

Man I love this forum.

Thank you for your wisdom!

 

[OzzyPeeps]

You'd have to take the pin out of the QD as well as the poppet out of the post to pump though - would that be an air tight connection?

But I guess there's some other connection that would do it

 

[Deadalus]

I have seen a SS pco tee, maybe Brewhardware.com. In general, that thread style is hard to find variety in the fittings.

 

[Deadalus]

You'd have to take the pin out of the QD as well as the poppet out of the post to pump though - would that be an air tight connection?

But I guess there's some other connection that would do it

The poppet is sealing the poppet hole, not the threads. So I don't think the threads would leak but there might more to it inside the post. But you could do it slightly differently and take the poppet out and get connected to the tee if needed.

 

[Deadalus]

Here's the pco1881 tee. Might be useful on the hop bong/randall side. There's a plastic one too, Kegland maybe?
https://www.brewhardware.com/product_p/carbonatorsstee.htm

 

[OzzyPeeps]

Food for thought. I will ruminate and report back.

There's a pco to bsp valve that could go either side of the bong ...

Then you are just down the two poppets ...

Enough people use same pump for keg to keg xfers and cleaning etc so I very much doubt it would be a problem.

But logically the larger the flow rate and the more pressure you can get into the system the more "contact time" and utilization you are getting, so... This brainstorming has been very useful as it may open the door to bigger pumps.

You're not getting around the dip tube diameter, that's the hard ceiling ...

But it's much, much easier to get info on which pumps can handle the geometry of that cylinder than it is to try and articulate the rest of it to non brewers!

Sláinte

 

[Gary25]

Wonderful thread, not sure how I missed it as hop flavor and aroma are obsessions of mine. Though I’ve used various dry hopping techniques, I’ve had positive results keg hopping.

I use fine mesh bags and typically use 8-10 ounces of hops per keg. No weights.

Closed transfer beer to Star San purged kegs. Connect CO2 to the serving keg liquid side, open lid, turn on CO2, drop in bag of hops. Purge and vent about six times. (Obviously this is imperfect, but positive CO2 flow should help; there will be air in the bag and around the hops).

After transfer, I pressurize the kegs to about 20PSI of CO2, leave at room temperature for three days (usually 65-75 degrees), then crash to serving temp and carbonate. No rolling, shaking or inverting—tried those and no noticeable difference I could detect. I am a hop creep embracer, as years ago had harsh results with a serving temp dry hopping, though it may have been a one off. I can easily soft crash the beer, so may give this a try.

I’ve never had grassy or other issues with extended time (months) in serving kegs.

Like Daytrippr mentioned, I too was keg hopping with open transfers and unpurged kegs long before O2 issues were understood. Flavors are better now; NEIPA keg hopping requires more CO2 purging or dry hopping in the fermenter.

As I brew 10 gallon batches, I typically dry hop the kegs with different hops and am always amazed at the different flavors—one of the things I like about keg hopping allowing me to try different hops on the same beer.

I like the ascorbic acid idea and will add that to my process along with soft crash and lower temp dry hopping techniques for ~3 days.

 

[Broken Crow]

The standard mesh on those things keeps almost all the mush in the press - and it's not that fine a mesh.

Using the appropriate mesh size in the bong, no chance they end up in the keg.

Thanks! That's probably where my reasoning screwed up...The first time I used my keggle I'd put my hop pellets in a non-standard mesh cylinder and they completely vanished into the wort so since that time I've just assumed they'd 'liquify' at least enough to pass hopefully without clogging. I think you just saved me from a messy experiment.

 

[RyPA]

apologies if there is a thread that addresses this, but Search didn't locate one.

I had always followed advice to dry hop no more than a week in the fermenter, then transfer to the serving keg.

lately I've seen discussions about dry hopping in the serving keg.

how does long-term dry hopping in the keg square with the previous conventional wisdom of 3-7 day dry hopping?

I would really like to move to keg hopping.

thanks!

For the past 3 years I've been fermenting and serving from the same keg, with 97.63% of the beers being NEIPA's that required dry hopping.

When it came time to dry hop, I would get a CO2 line ready and once I pop the keg lid I would begin running CO2 into the keg with a goal of producing an outflow of CO2, hopefully reducing O2 from getting in.

I would then pull out my iSpindel, dump the hops in (commando), secure the lid, build a bit of CO2 pressure, and then do 10 or so CO2 purges.

This process has worked for me with avoiding oxidation. The NEIPA's continued to look like fresh OJ & taste good until they kicked (1-2 months).