Back To Black (keg lid o-rings)

[YeastFace]

Interesting video from Kegland who have had the oxygen transmission of their regular silicon keg lid o-rings tested -

Result is the silicon o-rings does allow oxygen diffusion into the keg.

They do point out that at lower temperatures this diffusion is very much reduced.

My AEB kegs still have the black nitrile rubber o-rings, but my reconditioned ones the silicon ones. In no mad rush to replace as can't recall having any oxygen related off-flavours, but something to be aware of.

Edit - The test paper is available here.

Link seems to be broken so have attached the PDF.

 

[Sadfield]

I actually swapped to silicone on my kegs that I age mix fermentation beers for this reason. Wanting the small ingress of oxygen one would get with a large wood vat.

 

[YeastFace]

In the video Kee quotes a packaging technologist who has calculated that in a light lager at 0°c 1ppm O² would be reached within a week with the silicon o-rings.

That's concerning as I've just kegged an Italian Pils (so both light and hoppy - enemies of oxygen) using a new lid with these damn o-rings. I'm keg hopping so intended to transfer into another keg after 4-5 days so will use a black nitrile rubber in the receiving keg.

Would be interesting to do a side by side and see if there's any perceptible difference and maybe borrow a dissolved oxygen meter to test. I have 2 9.5l kegs so may do that one day.

 

[Rwilts]

Many years ago I replaced my o rings with ones that are are Red, anyone know which material these are?

 

[peebee]

Wow! Everyone is finally catching up with the high gas permeability of silicone-rubber?

I've no interest at all in what tiny amounts of oxygen might do negatively to the beers I brew, but I had silicone-rubber's gas permeability pushed down my throat years ago, and rant about it every now-and-again. Why do we use it after fermentation starts?

It's softer and creates better seals? That's one I've heard. Rubbers are formulated for different harnesses. 70 "Shore-A" (the unit for measuring rubber hardness) is typical for Nitrile rubber O-rings, whereas silicone-rubber O-rings are ... 70 Shore-A. Plenty of boll**** there then. I do use softer, and fatter, rings for low pressure seals; they are made from ... nitrile! You have to be careful with them because softer means "easily damaged".

Did learn some other useful facts after using silicone-rubber with fermenting beer: Yeast really grows well with plenty of oxygen. Bunged up all the silicone hoses I was using. And the fermenting wort in those pipes: Once the yeast starts starving it's quite happy switching to using oxygen to eat its own excrement (alcohol!) and convert it to vinegar. Good job the pipes were bunged up and the vinegar never made it to the bulk of fermenting beer.


Silicone rubber if very excellent for hot temperatures and the like before fermentation though.

 

[Buffers brewery]

Ooerr! As some of you may know I replaced the cap on my King Keg pressure barrels with my own design cap. It uses a HUGE silicone rubber seal….

I’ve brewed several NEIPA 5 gallon batches. All have survived 8-10 weeks after transfer from the fermentation bucket. All the beer was consumed without any indication of oxidation. I’m obviously doing something wrong! Why is my highly hopped beer not oxidising?

 

[hoppyscotty]

But though this stuff is gas permeable how much does it really impact things in the real world? I mean PET bottlers are gas permeable yet billions of litres of carbonated drinks are stored in them for periods of time and they don't lose carbonation very quickly...over many months if not longer...so as long as you're not storing beer for a long time I can't see it really matters. I mean triclamp seems to be the standard in beer fermenters and silicone gaskets widely used in the industry yet the resulting beer is perfectly fine.

If better products are available on the market then would be silly not to use them so when I need to replace gaskets I'll go for ones that are less or not gas permeable if they're available, but I don't think its a case of chuck out all your silicone gaskets overnight just yet.

Also beer in a keg is pressurised so can oxygen at a partial pressure of 3psi (at sea level) pass through a silicone keg seal where the inside is pressurised to 12 - 15 psi or something like that?

 

[hoppyscotty]

just watch the video and apparently pressure is irrelevant! oh well.

 

[Tess Tickle's Brewery]

This is fascinating - but I'm about to ask a rather silly question

Will this only be worth doing if you keep your beer in a closed loop all the time? ie if you syphon your beer over you've already kn@ckered it?

 

[peebee]

... Also beer in a keg is pressurised so can oxygen at a partial pressure of 3psi (at sea level) pass through a silicone keg seal where the inside is pressurised to 12 - 15 psi or something like that?

Yes!

And I don't have to try (and likely fail) to explain it ... listen to the attached (in OP) video.

[EDIT: Oops, too hasty! You've already figured that!

But I take this opportunity to explain my position in this ... I don't give a flying fig about "NEIPA" and its supposed susceptibility to oxidation. But I do approve of the publicity that silicone-rubber's gas permeability is getting.]

[EDIT2: ... And another thing ... ... I gripe about the fictional "soft" silicone-rubber O-rings, but that video does point out that the silicone-rubber ones are more resilient than nitrile. Still, I won't be switching my nitrile ones, and when it comes to the time that they've flattened and perished, we'll all be changing to the latest plant-based versions anyway. And I'll have long been converted to plant fertiliser by then.]

 

[Buffers brewery]

Just read that CO2 is 5 times more permeable in silicone rubber than oxygen! So the CO2 exits 5 times faster than the O2 enters!?
We're doomed, we're all doomed

 

[peebee]

... Will this only be worth doing if you keep your beer in a closed loop all the time? ie if you syphon your beer over you've already kn@ckered it?

Are you concerned that "syphoning" will introduce more oxygen than silicone O-rings, thus making replacing them unnecessary?

Nay! Syphoning shouldn't do that. Anyway ... you only have to follow @Buffers brewery to see how concerned he is about all this O-ring twaddle.

 

[Tess Tickle's Brewery]

Are you concerned that "syphoning" will introduce more oxygen than silicone O-rings, thus making replacing them unnecessary?

Yes exactly!

Because I'm such an OCD lunatic I'll probably replace them AND stop syphoning

 

[Buffers brewery]

Yes exactly!

Because I'm such an OCD lunatic I'll probably replace them AND stop syphoning

Don’t panic! Don’t panic!

 

[Buffers brewery]

I’ve had a couple of beers so I thought I’d take a look at the numbers in this Kegland marketingfest, hic. I’m sure @peebee will correct me if I go wrong.
So 11cc/day with 100% O2 @ 23C
With air that’s 2.2cc/day @ 23C
I think the boffin said 10% reduction per 1C so @ 13C that’d be 1.1cc/day.
Let’s assume cornies are stored at around 12C (makes the sums easier) then that’s 1 cc/day.
I’m guessing here that the average head space in a full corny is around 200 cc at 15psig. (This might be wrong).
During a 4 week carbonation and conditioning time, 28cc of O2 will permeate into the corny. At the same time 140 cc of CO2 will permeate out of the corny. So NET 112cc of gas out.
The headspace of 200cc equates to 400cc at atmospheric pressure, less the 112cc, lets say 100cc leaves 300cc at atmospheric pressure of gas in the headspace. If pv is a constant then the resulting pressure would be 7.5 psig.
Could this be the reason for the video? Customers are complaining that the new silicone seals are leaking and their beer is oxidizing?

 

[The Baron]

I will be honest I have never had a beer oxidise in my cornies. I have had them in for months and a stout for 2 years, now that maybe mostly that I use original style O rings but I did buy a few years ago what was described as fatter softer O rings which I can not remember what they are made of. They are black but much softer and fatter than standard ones I also have a couple of Blue and Dark orange ones.
As I have said none have failed me

 

[chopps]

I'm so glad I bought that CO2 blanket now or my beer would be ruined.

 

[dave_77]

My latest keg has the new o-ring..can't seem to buy the new ones outside of Australia yet. I would get the new ones, I spend enough time trying to keep O2 to a minimum so seems like a cheap addition. 4$ on keglands website.

 

[YeastFace]

My latest keg has the new o-ring..can't seem to buy the new ones outside of Australia yet. I would get the new ones, I spend enough time trying to keep O2 to a minimum so seems like a cheap addition. 4$ on keglands website.

None of the black nitrile rubber ones?

 

[dave_77]

None of the black nitrile rubber ones?

I think they are the ones that maltmiller and brewkeg sell. I have the yellow one on my newest keg...think they are white and pink on the others..no black