Dry Hopping

[rodwha]

I used to use muslin bags but found large tea baskets at World Market. Does anyone just toss their pellets in? Seems like it would end up in the bottles, which I don’t want.

This last time I put maybe 2 1/2 Oz in each basket but it swelled and floated, and clearly didn’t lend aroma very well.

I’ve been thinking of whole cones for this, but I like buying those hops in bulk for a better price.

 

[HobbitBeer]

You can sanitize a couple of marbles, toss them in the muslin sick alongside the hops, and the weight should fully immerse the hops.

You can use those tea baskets, but make sure they're completely stainless otherwise you're going to see rust over time.

You can also just toss the hops in and use a fining agent like gelatin to leave the hop particulate in the trunk when you keg/bottle.

 

[IslandLizard]

I toss dry hops (mostly pellets, much larger selection) in loose through an additional 1" port I drilled in the bucket lid. Then agitate (a gentle stir) twice a day for better extraction. Whenever the port is open I'm streaming CO2 in through the airlock. After a day, or 2, all dry hops have sunk, cold crashing for one day to 3 days does the rest.

As long as the swollen hop pulp inside the tea balls doesn't restrict beer flow in and out, I guess they're fine to use. You definitely need to agitate periodically (e.g., dunk, swirl, stir) to refresh the beer inside the containers for better permeation and extraction. Make sure they don't float, put a few marbles inside.

Prevent air (oxygen) intrusion during dry hopping and packaging. It oxidizes your beer and hops, killing hop sensation quickly.

 

[ALExanderH]

I dry hop loose and won't be changing that anytime soon, I chill my fermenter for 2-7 days depending on when I have time to keg. No issues with hop particles and great aroma and flavor.

 

[marchuk96]

You can sanitize a couple of marbles, toss them in the muslin sick alongside the hops, and the weight should fully immerse the hops.

You can use those tea baskets, but make sure they're completely stainless otherwise you're going to see rust over time.

You can also just toss the hops in and use a fining agent like gelatin to leave the hop particulate in the trunk when you keg/bottle.

I'd say if you have the capability to cold crash after dry hop then your best practice is going to raw dog the hops in there...no bag no tea ball...just hops and wort....I used to use sacks and switched to just throwing in hops once I had the ability to cold crash..a rather drastic improvement in my experience...dry hop for 2-3 days periodically rocking the vessel to agitate and then before bottling or kegging just place your vessel into the fridge for at least a day as cold as you can...the hops just drop out like rocks

And the gelatin idea while helping to clear your beer will really only take care of yeast in suspension...I will not drop your hop material...the colder temp will do that for you

 

[Vale71]

And the gelatin idea while helping to clear your beer will really only take care of yeast in suspension...I will not drop your hop material...the colder temp will do that for you

No it won't. Hop material is not alive and doesn't merrily "swim around" your wort only to drown and drop dead when you drop the temperature. The moment you drop hops in the beer they will start sinking to the bottom and will do so more slowly the colder your beer is. Telling people to cold crash the beer to accelerate sedimentation is the worst advice one could give as this will invariably achieve exactly the opposite result. This has been a well established scientific fact since 1851. I think it's time homebrewers finally caught on to it too...

 

[Jag75]

I always dry hop with a muslin bag and ss washers to weigh it down . In all my times of dry hopping without a weight of some sort the hop bag always floats . Once I used 2 shot glasses to weigh down a bunch of hops . After 5 days the bag was puffed up and floating, with 2 shot glasses inside mind you. This is why I've never dry hopped commando . I read how people dry hop commando and they say hops fall out but I also read about clogs too. Theres nothing worse then getting a clog and having to clean out the poppet or keg pick up tube because of hop particles. One of these days I'll dry hop commando then cold crash before I keg and see ......but I've been telling myself that for a while now lol.

 

[IslandLizard]

I read how people dry hop commando and they say hops fall out but I also read about clogs too.

I noticed the stirring twice a day helps tremendously in getting the floating hop carpet suspended. A good periodic swirl should achieve the same. After 1-2 days there is no more hop pulp floating, even the hops along the krausen line have submerged.

I've now gone to stirring every 3 hours the first 24 hours to speed things up. There's a good chance hop extraction has mostly completed after that first day already. This is at 68F.

To prevent transferring any stray hop pulp I use a fine nylon mesh filter baggy around the bottom of the racking cane (which also has the inverter tippy mounted) and start siphoning from the middle of the fermenter, lowering it as the beer level drops. Don't stick that racking cane all the way on the bottom. With about a gallon left, tilt the fermenter toward the cane to keep the siphon well deep.

 

[Jag75]

I noticed the stirring twice a day helps tremendously in getting the floating hop carpet suspended. A good periodic swirl should achieve the same. After 1-2 days there is no more hop pulp floating, even the hops along the krausen line have submerged.

I've now gone to stirring every 3 hours the first 24 hours to speed things up. There's a good chance hop extraction has mostly completed after that first day already. This is at 68F.

To prevent transferring any stray hop pulp I use a fine nylon mesh filter baggy around the bottom of the racking cane (which also has the inverter tippy mounted) and start siphoning from the middle of the fermenter, lowering it as the beer level drops. Don't stick that racking cane all the way on the bottom. With about a gallon left, tilt the fermenter toward the cane to keep the siphon well deep.

I guess I'm just baffled that my hops floated to the surface in a bag that was weighted down. Its hard for me to fathom them to totally drop while hopping commando. I'm not saying you guys are lying , it's just a hard concept to think if they float in a bag why wouldn't I expect them to float w/o a bag . I pressure transfer , using a cf5 . I usually swirl my fermenter while I'm dry hopping .

 

[IslandLizard]

I guess I'm just baffled that my hops floated to the surface in a bag that was weighted down. Its hard for me to fathom them to totally drop while hopping commando. I'm not saying you guys are lying , it's just a hard concept to think if they float in a bag why wouldn't I expect them to float w/o a bag . I pressure transfer , using a cf5 . I usually swirl my fermenter while I'm dry hopping .

Adding dry hops creates nucleation sites, causes CO2 to come out of solution. The bag must trap enough causing the buoyancy, even with 2 shot glasses in there.
When adding dry hops (pellets) to my NEIPAs, 3-4 oz for the first dose, followed by a gentle stir, I often get close to a gallon of green foam filling the headspace, so I quickly close the the port in the lid. I keep CO2 on to prevent air entering while the foam settles out. About an hour later give it another stir, usually without causing much foaming.

 

[marchuk96]

No it won't. Hop material is not alive and doesn't merrily "swim around" your wort only to drown and drop dead when you drop the temperature. The moment you drop hops in the beer they will start sinking to the bottom and will do so more slowly the colder your beer is. Telling people to cold crash the beer to accelerate sedimentation is the worst advice one could give as this will invariably achieve exactly the opposite result. This has been a well established scientific fact since 1851. I think it's time homebrewers finally caught on to it too...

I as well as many others used cold crashing with perfect success to drop hops...and they certainly don't resurface once the beer gets colder...a 24 hr crash usually gives me a complete drop in hop particulate and drops a bunch of yeast leaving a tightly packed layer on the bottom of my fermntor...as temp goes down the molecular mass of hops increases..making them more dense...this increase in density is what drops them to the bottom...

And there has been plenty of studies done on dry hopping...while using bags isnt bad practice...it is less efficient....

A lab trial was conducted to test whether using a finely woven sack reduced the solubility of the hops. Two separate green beers were dry hopped, one loose and the other in a sack. They found that the hops that were floating loose in the beer tested with almost 50% more linalool than the beer with hops in a sack,

http://scottjanish.com/examination-...s-for-achieving-maximum-hop-aroma-and-flavor/

 

[day_trippr]

[...]Telling people to cold crash the beer to accelerate sedimentation is the worst advice one could give as this will invariably achieve exactly the opposite result. This has been a well established scientific fact since 1851. [...]

Am I to believe something that defies observation?

When you throw something in the face of folks that watch their hops suddenly fall from the surface with a mere 10-15°F drop in temperature, solid convincing citations are expected...

Cheers!

 

[Vale71]

I as well as many others used cold crashing with perfect success to drop hops...and they certainly don't resurface once the beer gets colder...a 24 hr crash usually gives me a complete drop in hop particulate and drops a bunch of yeast leaving a tightly packed layer on the bottom of my fermntor...as temp goes down the molecular mass of hops increases..making them more dense...this increase in density is what drops them to the bottom...

I'm sorry but your theory has nothing to do with reality. Hop material is always heavier than beer and starts dropping immediately, unless there is still CO2 evolving because of fermentation which might cause them to float and mix with the Kräusen. However that's another issue and should not happen if you dry hop when fermentation has finished and the Kräusen has dropped.

FYI water (and hence beer) increases in density with decreasing temperature too so that the two effects practically cancel each other out.

 

[Vale71]

Adding dry hops creates nucleation sites, causes CO2 to come out of solution. The bag must trap enough causing the buoyancy, even with 2 shot glasses in there.
When adding dry hops (pellets) to my NEIPAs, 3-4 oz for the first dose, followed by a gentle stir, I often get close to a gallon of green foam filling the headspace, so I quickly close the the port in the lid. I keep CO2 on to prevent air entering while the foam settles out. About an hour later give it another stir, usually without causing much foaming.

Have you tried not stirring and just letting them sink?

Agree that using a bag is a good way to trap CO2 and have everything float like a small Zeppelin.

 

[IslandLizard]

Have you tried not stirring and just letting them sink?

Yes, I have in the (very) past. Most sink eventually, but even after 5 days to a week some larger rafts were left on top as well as a good covering along the krausen line, very visibly in carboys I was using then.
Those were after only relatively small dry hop additions, 1-2 oz (occasionally 3 oz) in a 5 gallon batch.

Somewhere during 2014, soon after reading PH Wolfe's thesis on dry hopping, I started to agitate. Swirling first, stirring later, once a day during the 5-7 days of dry hopping. When brewing more aggressively dry hopped IPAs and later NEIPAs, I felt I needed to speed up hop extraction drastically, and do so more completely. A homebrew scale Hop Gun would be wonderful to have.

I sometimes brew 3-day NEIPAs, and none are longer than 7 days in the fermenter.

 

[marchuk96]

I'm sorry but your theory has nothing to do with reality. Hop material is always heavier than beer and starts dropping immediately, unless there is still CO2 evolving because of fermentation which might cause them to float and mix with the Kräusen. However that's another issue and should not happen if you dry hop when fermentation has finished and the Kräusen has dropped.

FYI water (and hence beer) increases in density with decreasing temperature too so that the two effects practically cancel each other out.

My "theory"is actual science man...Water is one of the few exceptions..and you must be using those new leaded hop pellets that "sink immediately" because mine sure float from the time they go in until i crash...some particulate does sink but the bulk is left floating on top in an even layer...even after day 2 or 3 with aggitation...even luplin powder floats on top...attached pic represents a dry hop done after fermentation was over and just prior to placing in fridge for crash...majority of hops still on top...

 

[day_trippr]

Two words: hop creep

I rather doubt brewers in 1851 had a clue...

Cheers!

 

[BrewnWKopperKat]

To prevent transferring any stray hop pulp I use a fine nylon mesh filter baggy around the bottom of the racking cane (which also has the inverter tippy mounted) and start siphoning from the middle of the fermenter, lowering it as the beer level drops. Don't stick that racking cane all the way on the bottom. With about a gallon left, tilt the fermenter toward the cane to keep the siphon well deep.

^^^ this ^^^ is excellent advice for those who bottle (well, at least in IMHO - I bottle this way).

 

[IslandLizard]

Don't stick that racking cane all the way on the bottom. With about a gallon left, tilt the fermenter toward the cane to keep the siphon well deep.

Many videos show the auto siphon (or racking cane) resting on the bottom of the fermenter, in the middle of the trub before they start siphoning from there.
Instead, use a siphon clamp or something to suspend the sipon/cane well above the trub.

If you do closed transfers (lid remains on, CO2 replaces beer as it's siphoned out) use a stopper or something to retain the cane in the lid along the side of the fermenter. Toward the end, as soon as you see trub entering the siphon tube or racking hose, stop the transfer immediately. Be prepared to do so in one swift motion without sucking air and blowing it through your carefully siphoned beer.

Rehearse with a bucket of water until you've got the workings and timing down to a T.

 

[VirginiaHops1]

No it won't. Hop material is not alive and doesn't merrily "swim around" your wort only to drown and drop dead when you drop the temperature. The moment you drop hops in the beer they will start sinking to the bottom and will do so more slowly the colder your beer is. Telling people to cold crash the beer to accelerate sedimentation is the worst advice one could give as this will invariably achieve exactly the opposite result. This has been a well established scientific fact since 1851. I think it's time homebrewers finally caught on to it too...

Since you were so specific with your info down to the exact year I'm assuming you have a citation or source? Or was that for effect?

 

[Vale71]

There you go:

https://en.wikipedia.org/wiki/Stokes'_law

 

[Vale71]

My "theory"is actual science man...Water is one of the few exceptions..and you must be using those new leaded hop pellets that "sink immediately" because mine sure float from the time they go in until i crash...

So you're saying that hop material invariably floats because its density is lower than that of beer, right?
Have you ever used hops for bittering? I assume you have and you probably used pellets for that as well. Now as you must know wort has an even higher density than finished beer even accounting for temperature at flame out, so according to your theory at flame out hop material should immediately shoot to the surface and never drop to the bottom of the kettle no matter what you do.
Is this what you have observed? If the answer is no than you have just disproved your own theory and according to the scientific method you need to formulate a different theory to account for the actually observed behaviour.

 

[marchuk96]

So you're saying that hop material invariably floats because its density is lower than that of beer, right?
Have you ever used hops for bittering? I assume you have and you probably used pellets for that as well. Now as you must know wort has an even higher density than finished beer even accounting for temperature at flame out, so according to your theory at flame out hop material should immediately shoot to the surface and never drop to the bottom of the kettle no matter what you do.
Is this what you have observed? If the answer is no than you have just disproved your own theory and according to the scientific method you need to formulate a different theory to account for the actually observed behaviour.

I'm saying hops float when you start dry hop...and basically remain there until you cold crash...

 

[Jag75]

I've got some old hops . I'm gonna get a BMC and dry hop at room temp. I'm curious to see what happens . Vale 71 actually makes a good point about hops in the boil and wort being more buoyant then beer however the hops do drop to the bottom. Or do the hops stay suspended until we drain the kettle......hmmm. we need a clear kettle lol

 

[Dgallo]

No it won't. Hop material is not alive and doesn't merrily "swim around" your wort only to drown and drop dead when you drop the temperature. The moment you drop hops in the beer they will start sinking to the bottom and will do so more slowly the colder your beer is. Telling people to cold crash the beer to accelerate sedimentation is the worst advice one could give as this will invariably achieve exactly the opposite result. This has been a well established scientific fact since 1851. I think it's time homebrewers finally caught on to it too...

Cold crashing will drop hops out of suspension along with yeast and any remaining nonbound protiens. Temperature changes molecular density of wort and materials and it’s Same reason you need to do temperature corrections of wort gravity when it’s warm verse room temperature. Higher density than the wort will drop as temp drops. It’s that simple

 

[Dgallo]

So you're saying that hop material invariably floats because its density is lower than that of beer, right?
Have you ever used hops for bittering? I assume you have and you probably used pellets for that as well. Now as you must know wort has an even higher density than finished beer even accounting for temperature at flame out, so according to your theory at flame out hop material should immediately shoot to the surface and never drop to the bottom of the kettle no matter what you do.
Is this what you have observed? If the answer is no than you have just disproved your own theory and according to the scientific method you need to formulate a different theory to account for the actually observed behaviour.

No, your wort is boiling and is having breaks in it’s surface tension. Completely invalid argument. Pellets have varying density’s to begin with due to the variety of hop, oil content, and pelletizer. I’ve had dryhop pellets that were denser and sunk right away at roomtemp and I’ve had pellets that would float for days before they would drop out or be crashed out.

 

[Jag75]

Cold crashing will drop hops out of suspension along with yeast and any remaining nonbound protiens. Temperature changes molecular density of wort and materials and it’s Same reason you need to do temperature corrections of wort gravity when it’s warm verse room temperature. Higher molecular weight than the wort will drop as temp drops. It’s that simple

This makes sense now . I never thought why we check gravity at a certain temp. So the colder it gets the less buoyant it is right?

 

[cubalz]

I just chuck them into the fermenter loose and then filter them out when I transfer the beer to the keg. Reason is: not using a hop bag means one less thing to sanitize and clean. Also less risk for infection IMO. Been doing it this way for years without issue.

 

[Dgallo]

This makes sense now . I never thought why we check gravity at a certain temp. So the colder it gets the less buoyant it is right?

It’s the hops density increases and become less buoyant. The wort theoretically will get more buoyant force

 

[Jag75]

Studies have shown that hops dont need to be in the fermenter for more then 3-5 days. So how does one do a dbl dry hop beer if your tossing commando? Is that why people get hop creep? You cant pull em out without a bag . I will agree with cubalz , it would be easier just tossing in and not worrying about a bag . I just dont want any clogging .

 

[Jag75]

It’s the hops density increases and become less buoyant. The wort theoretically will get more buoyant

Ok so as the temp drops the hop particles get heavier , causing them to sink ? But the beer becomes more buoyant as the temps drop? This is interesting stuff imo so I'm trying to understand. I should have paid more attention in science class .

 

[Dgallo]

Ok so as the temp drops the hop particles get heavier , causing them to sink ? But the beer becomes more buoyant as the temps drop? This is interesting stuff imo so I'm trying to understand. I should have paid more attention in science class .

So the hops don’t get heavier, their mass stays the same. They get denser

 

[Brooothru]

No it won't. Hop material is not alive and doesn't merrily "swim around" your wort only to drown and drop dead when you drop the temperature. The moment you drop hops in the beer they will start sinking to the bottom and will do so more slowly the colder your beer is. Telling people to cold crash the beer to accelerate sedimentation is the worst advice one could give as this will invariably achieve exactly the opposite result. This has been a well established scientific fact since 1851. I think it's time homebrewers finally caught on to it too...

I remember you posting about this on another thread recently (can't find it though) and remember agreeing with the science. But something struck me about the temperature/density curves and how they related to settling. Not sure if it was your post or something I read while researching topics you referenced, but I seem to recall that falling temperature actually did increase settling up to a point, after which the increased density of the liquid became a limiting factor. Temperature where the inverting of the curve occured might have been around 48F or so.

Might there be something else going on? For instance, Spike Brewing tells users of their glycol chillers to reverse the feed lines with the return lines when chilling below 40F due to an inverting of the convective currents within the fermenter when reaching lower temperatures. I didn't understand the physics behind what they were saying nor did they go into any depth to explain it. Maybe just junk science or maybe a possible explanation as to why (other than inertia) so many people believe cold crashing works.

Brooo Brother

 

[cubalz]

Studies have shown that hops dont need to be in the fermenter for more then 3-5 days. So how does one do a dbl dry hop beer if your tossing commando? Is that why people get hop creep? You cant pull em out without a bag . I will agree with cubalz , it would be easier just tossing in and not worrying about a bag . I just dont want any clogging .

I should mention that I do not double dry hop. My method is for a singular dry hop addition 3 days before kegging.

 

[Vale71]

No, your wort is boiling and is having breaks in it’s surface tension. Completely invalid argument.

I think I mentioned "flame out" a few times. This implies that the wort is no longer boiling when we actually assess the behaviour of the pellets, regardless of at which point in time they were addedd. As soon as convection stops buoyancy will decide whether the material either sinks or swims to the surface. Particle size and fluid viscosity will determine how fast this will happen according to the principles set forth in Stokes' Law.

Hydrated hop material is made up of 80% water and its total density is higher than that of water since its dry matter constituents have a higher density than that of water. As temperature changes the water component will track the density of the surrounding fluid and its net buoyancy will always remain zero. This means that the total buoyancy will always be determined exclusively by the buoyancy of the dry matter portion which is mostly made of lignin which in turn has a specific density higher than that of whater (around 1.5 times that of water within a small range of variation depending on the actual structure of the polymer), at least in the range of temperatures where water is in liquid form.

FYI pellets added during boil hydrate very quickly thanks to temperature and once boiling stops they sink really fast because at those temperatures wort viscosity is at its lowest.

 

[Vale71]

I remember you posting about this on another thread recently (can't find it though) and remember agreeing with the science. But something struck me about the temperature/density curves and how they related to settling. Not sure if it was your post or something I read while researching topics you referenced, but I seem to recall that falling temperature actually did increase settling up to a point, after which the increased density of the liquid became a limiting factor. Temperature where the inverting of the curve might have been around 48F or so.

Might there be something else going on? For instance, Spike Brewing tells users of their glycol chillers to reverse the feed lines with the return lines when chilling below 40F due to an inverting of the convective currents within the fermenter when reaching lower temperatures. I didn't understand the physics behind what they were saying nor did they go into any depth to explain it. Maybe just junk science or maybe a possible explanation as to why (other than inertia) so many people believe cold crashing works.

Brooo Brother

That was probably a reference to one of water's many anomalies, namely the fact that water's density starts decreasing below about 4.13 °C. And then it decreases even more when water solidifies which is the opposite of what normally happens when going from liquid to solid.
This is however not relevant as far as Stokes' Law is concerned as the property we're interested in is actually dynamic viscosity and that increases monotonically with decreasing temperature all the way to the actual phase change.
This does however cause reversal of convection possiby necessitating changes in the cooling system. IMHO this is however not really necessary in very small vessels where direct heat transfer is more than adequate and convection is not really necessary.

 

[Vale71]

I think that at this point we need to assess an issue that is probably causing confusion, that of gas entrapment.
If we drop particulate in a fermenter as CO2 is still evolving than we can expect those solids to become (at least in part) attached to evolving CO2 thus becoming buoyant. This is exactly what happens to yeast that gets carried to the surface forming the Kräusen. Yeast are not motile and cannot swin in any direction and their density is also higher than that of water/wort/beer, so from the very moment we pitch them they start sinking to the bottom. What keeps them in suspension is a mixture of natural convection due to the exothermic nature of fermentation and their becoming attached to CO2 bubbles that will give them buoyancy.
There is no reason for hop matter to behave differently. Even if yeast is alive it still is mechanically inert just like a dissolved hop pellet. This means that if you observe hop material floating to the surface than the hop itself is not to blame but rather the conditions in the wort when the hops were added.
I can guarantee ('cause I do it all the time) that if you drop hop pellets in fully fermented and carbonated beer in a pressurized vessel when fermentation is 100% finished and there is no visible Kräusen you will start collecting hop material just a few hours later and the warmer the beer the faster hop material will collect at the dump valve. You also get better aroma extraction which is also very nice to have...

 

[Vale71]

And for the stubborn skeptics here is a simple experiment.

Fill a small container with room-temperature water. Dissolve enough sugar to achieve a density of about 1.020. Drop a few hop pellets in. Leave undisturbed and observe.

 

[Brooothru]

I remember you posting about this on another thread recently (can't find it though) and remember agreeing with the science. But something struck me about the temperature/density curves and how they related to settling. Not sure if it was your post or something I read while researching topics you referenced, but I seem to recall that falling temperature actually did increase settling up to a point, after which the increased density of the liquid became a limiting factor. Temperature where the inverting of the curve occured might have been around 48F or so.

Might there be something else going on? For instance, Spike Brewing tells users of their glycol chillers to reverse the feed lines with the return lines when chilling below 40F due to an inverting of the convective currents within the fermenter when reaching lower temperatures. I didn't understand the physics behind what they were saying nor did they go into any depth to explain it. Maybe just junk science or maybe a possible explanation as to why (other than inertia) so many people believe cold crashing works.

Brooo Brother

Stokes' Law. That's what I was thinking about.

Eventually just about everything settles to the bottom of the ocean. If you look at deep submersibles when they reach the oceans' floor, even Challenger Deep at over 36,000' below sea level has shown extremely fine settled material. That's about as dense as any water gets (plus ocean water at that depth is much more saline, thus denser). The water temperature has been isothermic for probably 20,000' of depth or more. The fine particulate has not increased in mass, yet it has settled, and the undisturbed water is incredibly clear. Somehow this all occurs without violating Stokes.

I'm sure there must be holes in my thinking. I have enough 'surface knowledge' to opine and speculate but I don't have the insight to explain or justify it. I can only believe there is something being overlooked in the pro and con of this discussion.

Brooo Brother

 

[day_trippr]

lol at "causing confusion". With all due respect, using Stoke's in this context seems exactly that.

Stoke's knows nothing about CO2 evolution or any other "elevating force", so to speak. It presumes its environment is devoid of such considerations. So while its tenets may be entirely accurate, the system said tenets exist within does not resemble a vessel full of yeast.

Given how rapidly I can drop a full inch of pellet mush that's been floating at the top of my fermentors for four or five days to the bottom by the time the beer hits 50°F, my presumption as to cause had nothing to do with Stokes or even fluid dynamics in general, but that I've simply stunned the active yeast population into inactivity. No evolving CO2, nothing to keep the pellet raft afloat.

And I do want the hops out of the beer after 4-5 days and get the beer in a cold keg to keep the "creep" to a minimum, and considering I always let my pellets swim free the only way to go is a solid crash under CO2...

Cheers!