FYI this is a thread in the General Homebrew Discussion section. Just because it's about oxygen doesn't make it a "LODO thread" and you certainly don't own it in any way. If you don't like my comments you are free to respond as you see fit, taking issue with my partecipation is however totally out of place and very indicative of your general attitude.
No oxygen dry hopping
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davidabcd
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So, most here are still chasing the ultimate way to implement hops into a brew? A "noble" or European endeavor. When can a final solution be expected?
I'm a billion miles behind everyone else based on what I've been reading.
I'm a billion miles behind everyone else based on what I've been reading.
Cavpilot2000
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I would never discourage anyone from participating in a discussion. But the title of the thread is "No Oxygen dry hopping", which you took as an opportunity to come on with an aggressive and inflammatory tone ("you LODO converts", "Panties in a bunch") to basically tell people they're wasting their time and know nothing about oxygen ingress and material permeability.
My issue was not with your participation, but with your "I know everything and you people are idiots" attitude.
We're all just trying to make better beer here. Participation should contribute to that goal, not to insulting people with whom you disagree just because you think their methods are "unproven" (that's another discussion altogether because they are proven, but this isn't the place to get into that).
ANyway, I was wrong for taking your inflammatory bait, but I stand by my point that your attitude was unproductive, unconstructive, and unwelcome.
Now let's move on with the trying to improve our beer discussion.
You are right, I was wrong at the time in generalizing my comments as it was still just one convert who was parading his ignorance with his snide comments. Funnily enough lots of other converts then chimed in and proved that my generalization was not that far off the mark anyway.
Once again, your crowd does not own a thread just beacuse it's about oxygen and its effects on beer and you've crowned yourselves the world experts on the subject, so your remark that I somehow "came in on a LODO thread" is really way off the mark in this context.
Once again, your crowd does not own a thread just beacuse it's about oxygen and its effects on beer and you've crowned yourselves the world experts on the subject, so your remark that I somehow "came in on a LODO thread" is really way off the mark in this context.
I actually hadn't realized that your setup allows you to actually insert the hops and purge the chamber shortly before opening the valve and dropping the hops in the beer. In that case tough I must ask, why the 6-day vacuum test?Lol, no, it's not a concern with a dry hopping chamber considering the what, one minute that the hops are in there for? I'm on day 5 or 6 of a vacuum test. Those silicone screen doors are still holding vacuum.
I think this solution is so brilliant that I just ordered me a 3-way TC valve assembly to be able to do the same with my setup, thus rendering any issue relating to hop storage moot and also potentially allowing for multi-stage dry hopping.
An then I ordered myself some extra gaskets too. Viton gaskets, obviously...
Yes, FKM (also known as Viton) is as fine as EPDM or teflon or silicone for food applications. They are all compatible with beer/wort and the cleaning/sanitizing products we use as well.
As for the ginormous gasket being a real concern, I'd say that depends on whether you actually use the unitank as it is meant to be, that is to hold beer until it is fully conditioned and ready to package, which for a lager might mean several months storage. As diffusion is a function of time then O2 ingress can become a concern. If you're just doing primary and then transfering than it's no worse than any other fermenter with a silicone gasket. At least this one does seal properly (provided it doesn't fall into the fermenter as some users have reported).
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This seams like a very simple solution.
Unless I'm misunderstanding this, you want to add this post/late fermentation when most of the co2 generation is done. So I guess you're all doing closed and pressurized transfers after the dry hopping is complete.
How many of you wanting to do this are actually spunding?
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Well, I figured you were. Trying to figure out how this works with spunding.[WAVES AT THE TEACHER]
Me me me...
How many are waiting a week or more or is this happening on day two after pitching? Probably not spunding in this case.
My question is about the CO2 scrubbing and the timing of hop drop. Then dropping to the keg. What's been typical for those who spund?
I do fermentation purges, and closed transfers however with gravity using a return line back to the fermentor.
More importantly, since I spund I drop to the keg on day three or four. Hence the CO2 scrubbing question. (Still scratching my head)
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I'm still playing around with timing but the general idea is to have the beer more or less fully conditioned before dropping the hops in so that one can start serving as soon as the hop debris has fully settled and has been dumped succesfully. The idea of course is to let the hop aroma age as little as possible and not just to avoid CO2 scrubbing. BTW I also start serving straight from the unitank to avoid any oxygen exposure but end up having to fill a 5 gallon keg at the end as SS Brewtech's cooling system does not allow cooling with less than about that amount of beer left in a 14 gal unitank.
Once I get the 3-way valve I might even consider dropping in a smaller charge of hops to freshen up the aroma once half of the beer has been served but I think that might end up being a little over-the-top...
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I'm in the middle of moving and this all I can think of......
Meanwhile my wife is yelling at me to get my head in the game. LoL
Meanwhile my wife is yelling at me to get my head in the game. LoL
Cavpilot2000
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My next experiment on this front is going to be adding my final dry hop addition at about the time I would spund (fermentation almost complete, but maybe 4 or so gravity points left) and then let it finish out. Hopefully the last bit of fermentation will mitigate O2 introduced during the dry hop addition. THen I plan to let it sit for 3 days, fermenter prime it, and keg/spund as soon as I see signs of fermentation again (with fermenter priming when I've missed the spund, I usually see activity again in a few hours - like prime at dinner time and ready to keg before bed).
That way the fermenter prime should consume O2 introduced during the prime and keg process.
I'm doing this to avoid keg dry hopping, which I don't love.
That way the fermenter prime should consume O2 introduced during the prime and keg process.
I'm doing this to avoid keg dry hopping, which I don't love.
hopjuice_71
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Thanks for the response.. ..apologies, but I am biochemist, not a materials scientist, so I am still trying to understand the concept (very sorry if this is off topic). I fully get what diffusion is. In my mind I'm picturing this as diffusion of the gas atoms through the spaces of a microporous material and presumably those same pores can be occupied by CO2 or O2 (or other gases) as they transit the material. However, if there is significant pressure of one gas on one side of a silicone barrier (i.e. a high concentration of that gas, in this case CO2) would there not be a strong driving force for those gas molecules to saturate the pores of the material, thus limiting the capacity for another gas, O2, to travel thought the pores in the opposite direction? Kind of a mass transfer barrier? By analogy, I'm sort of thinking of crowds of people (the CO2) pushing to exit the limited number doors of a busy sports arena (the pores of silicone) at the end of a game and then a handful of people (the O2) trying to go in those doors. Then again, I guess this idea doesn't hold in the case of bottle caps, unless those materials are selectively permeable to gases. Am I just not thinking about this correctly?
I have assumed that this concept helps protect kegged beer.. ..as I just assumed keg o-rings were made of silicone (all the o-rings we use at work, which look similar, are silicone). But, the google-tron is telling me keg o-ring can be silicone or nitrile rubber, I guess the latter is more common. Are people who are worried about post fermentation O2, like me, using keg o-rings made of other materials?
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I occasionally do the keg prime during the dry fermentor purge if I'm think I won't be home in time properly spund. Typically if work requires me to do last minute travel.
This paper might help understand the mechanism of gas diffusion. Basically gas molecules in elastomers behave like gas molecules going into solution although in a somewhat solid medium. In the medium the concepts of pressure cease to be meaningful so that concentration gradients are the only parameters determining in which direction gases will diffuse.
Standard keg gaskets are usually made of EPDM because not only does it prevent diffusion of O2 into the keg but also becuase if they come in contact with the product they will not stain as easily as silicone rubber. Silicone stains like crazy, another side effect of its extremely high porosity.
As for the medium becoming saturated, this is certainly a possibility just like beer can become saturated with CO2 to the point that it won't be able to absorb any other gas. The problem in both instances is that to reach saturation you'll need such a high concentration of CO2 and hence such a high pressure that this will never happen in normal conditions as are to be found in a keg or in a fermenter. Incidentally, the higher the diffusivity of a gas in an elastomer, the harder it will be for it to become saturated.
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This is what has me stumped. The cost difference seems quite small. Is it possible the silicone gaskets are easier to use in hands of novices? Are they squishier for example at typical cold side brewery temps?
And has anyone tried sourcing a lid gasket for the spike Unitanks made out of anything other than silicone?
EPDM and FKM are definitely stiffer but at normal temps I've never had issues putting them on. Now if you were to brew in the open in Northern Canada maybe, but otherwise there's really no need to use this inferior material in brewing practice.
If anyone cares, a Food Saver Deluxe can only pull 20" Hg after about 5-10 attempts (the vacuum kept increasing until it plateaued at 20").
This thing pulled way more. Like all of it. I'm wondering if there's any point of purging with CO2 when you can pull this much vacuum. Obviously you would have to add some CO2 to the hop chamber so you don't pull vacuum in the fermenter when you try to drop the hops, but you have to wonder if multiple CO2 purges are necessary after pulling this much vacuum on the hops.
This thing pulled way more. Like all of it. I'm wondering if there's any point of purging with CO2 when you can pull this much vacuum. Obviously you would have to add some CO2 to the hop chamber so you don't pull vacuum in the fermenter when you try to drop the hops, but you have to wonder if multiple CO2 purges are necessary after pulling this much vacuum on the hops.
VirginiaHops1
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I found nothing wrong with his post. He didn't even say he thought LODO was a waste of time. He simply pointed out a potential flaw and backed it up with actual data. I agree that the counterpoint that the effect may be negligible if the beer is exposed to that material for a short amount of time makes sense though, and doing thorough tests on final DO levels in various scenarios would shed more light on it.
So if you concede that silicone isn't good for tap lines because of this O2 permeability issue what do you use? I don't use silicone but I'm definitely not using something $$ like viton. I think mine is just normal PVC. It's never even crossed my mind to worry about that, and I take limiting O2 exposure very seriously, so I find posts like this very enlightening.
monkeymath
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I don't usually brew hoppy beers - mostly because I prefer other styles, but also because I don't have kegs and think hops and bottles don't go well together, especially since I like to have a variety of beers around and thus do not consume them very quickly.
But I recently brewed a fruity Pale Ale for a friend and the oxygen ingress really had been bothering me. Put it in while there's still some fermentation? Possibly good to 'refill' the headspace with CO2, but possibly results in a NEIPA-style brew which is even more susceptible to oxygen. Eh. Maybe it's not an issue I should worry about because I'm adding much much more oxygen later on anyways, during bottling.
And please: let's be civil and constructive instead of discussing who knows best and why.
But I recently brewed a fruity Pale Ale for a friend and the oxygen ingress really had been bothering me. Put it in while there's still some fermentation? Possibly good to 'refill' the headspace with CO2, but possibly results in a NEIPA-style brew which is even more susceptible to oxygen. Eh. Maybe it's not an issue I should worry about because I'm adding much much more oxygen later on anyways, during bottling.
And please: let's be civil and constructive instead of discussing who knows best and why.
You absolutely do NOT have to dry hop while there is still some fermentation happening. In fact, many NEIPA brewers are now waiting until fermentation is completely done, crashing the yeast out, and then dry hopping. I tried it on my last two batches and there was no difference in terms of oxidation. Bottling is likely what screwed you.
Finally found my source:
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2003JD004073
Just look at Table 1. Of interest is also the permeabilty to water of Viton (40) compared to silicone (8000). Guess which material stains more easily if it comes in contact with beer?
Accordin to this table PTFE is basically an impenetrable barrier.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2003JD004073
Just look at Table 1. Of interest is also the permeabilty to water of Viton (40) compared to silicone (8000). Guess which material stains more easily if it comes in contact with beer?
Accordin to this table PTFE is basically an impenetrable barrier.
monkeymath
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Well, I haven't been screwed yet (fingers crossed), so we'll see. It seems the impact of oxygen added during dryhopping is still a matter of debate. (... Although the debate in this thread seems to be shifting in another direction...)
I guess I'll first try to devise some method of capturing CO2 so I can safely cold-crash and have the fermenter fill with CO2 during bottling. Then there's still oxygen in those bottles and in all hoses attached, but eh. If I can brew 999 other delicious styles of beer, I won't fret about my ability to brew hazy NEIPAs.
I just learned Stout has a solution to the problem:
https://conical-fermenter.com/dry-hop-doser.html?cat=111
https://conical-fermenter.com/dry-hop-doser.html?cat=111
It's strange that they're marketing it as a dry hop doser since all it is is a tri-clamp spool with a 1/4" npt port on it. You'll need quite a few more part to make it work! You can easily make something much better with off the shelf parts.
Gravitysucks
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I have. It's in post #224:
https://www.homebrewtalk.com/forum/threads/no-oxygen-dry-hopping.663500/page-6#post-8659917
Ok, how much more than $36.74 did those solutions cost?
Cheers!
Cheers!
That's like comparing the cost of a bicycle part to a ready to run race car.
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I think you need to read Wolfgang Kunze.
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Did you defeat the purpose?
Isn't there like more than $36 worth of tri-clamps alone in these "solutions"?
Cheers!
Cheers!
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Prolly
I'm guilty. When it comes to pizza, beer and sex.
Oh, and smoked meats....
Gravitysucks
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If you add up all the parts Stout says you need to complete the Dry Hopper it comes to $168.70. Mine was only slightly more than that and if I had used parts I had on hand rather than the second Spike manifold it would have been under $100. Whether the "money spent/improvements to beer" ratio ends up in the plus category remains to be seen but it was a fun project and I think that's half the fun of homebrewing.
Just ignore day trippr. He HAS to be trolling.
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Trolling for likes! [emoji16]
couchsending
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I don’t understand these elaborate dry hopping devices when you have a unitank. Bung at the very tail end of fermentation to at least create some head pressure, connect Co2 and pump into headspace while opening the top port and quickly dump you hops in. Purge headspace a few times.
You listen to so many professional brewers of great hoppy beers and almost all have gone back to this method. The old traditional way of pumping Co2 in through say the CIP arm and dumping in through the top port.
You listen to so many professional brewers of great hoppy beers and almost all have gone back to this method. The old traditional way of pumping Co2 in through say the CIP arm and dumping in through the top port.
