Fatter low-permeability tubing?

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sibelman

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To prevent clogs during closed transfer I've sometimes removed the keg post and stretched silicone tubing over the keg port as if it were a hose barb. This works well, but silicone is famously very permeable to oxygen. Of course, cold crashing, care with racking arm angle, and filtering also reduce clog risk, but those keg poppets can still clog. Any suggestions for low-permeability tubing for this application?
 
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sibelman

sibelman

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Follow-up for anyone who maybe knows (@Vale71, I'm thinking of you): any info about oxygen permeability of beige 1/2" I.D. 3/4" O.D. "thermoplastic tubing" (Santoprene?) ?

I still have a couple of pieces I bought from Northern Brewer ~10 years ago. There's no labeling on the tubing that I can see.
 

day_trippr

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Is there no vinyl/pvc tubing that would work for this transfer process?
When I do a CO2-push racking from carboy to keg my SS racking cane press-fits 3/8" ID tubing - which also is a tight fit on the bare 1/4" mfl threads on a beer QD....

Cheers!
 
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sibelman

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Is there no vinyl/pvc tubing that would work for this transfer process?
When I do a CO2-push racking from carboy to keg my SS racking cane press-fits 3/8" ID tubing - which also is a tight fit on the bare 1/4" mfl threads on a beer QD....

Cheers!
I've probably got some vinyl that would work, but... I take it you're saying vinyl is much less oxygen permeable than silicone? ( though EVAbarrier is even better)

Sometimes, in pursuit of oxygen avoidance, I strongly feel the lack of solid data. Folks say, omg it made a big difference. But no one reports measuring dissolved oxygen. Just : my hop aroma lasted more / less. Sorry for the rant, and thanks for any ideas even when totally subjective 😁
 

eric19312

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I'm not sure why you are going to worry about the permeability of the silicone hose if you are then going to fill the beer into an unsealed keg. Once you take the hose off the port to reattach the post you have an open keg.

Like you said good cold crashing and racking technique will usually be enough to deal with the issue. I've been using an inline filter as insurance against when it is not but TBH there is rarely anything in the filter when I clean it after kegging.

IMG_0883.jpeg
 
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sibelman

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I'm not sure why you are going to worry about the permeability of the silicone hose if you are then going to fill the beer into an unsealed keg. Once you take the hose off the port to reattach the post you have an open keg.

Like you said good cold crashing and racking technique will usually be enough to deal with the issue. I've been using an inline filter as insurance against when it is not but TBH there is rarely anything in the filter when I clean it after kegging.
Your setup is inspiring, and I'm glad you've so thoroughly conquered clogging. I'm considering a filter, based largely on your success.

Re "unsealed keg" : technically, yes, but exposure of the top of the dip tube to air for a few seconds will "surely" allow only a tiny amount of oxygen. To be fair, this intuition is not supported by any data. I'm still curious about fat barrier tubing though.
 

Vale71

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Follow-up for anyone who maybe knows (@Vale71, I'm thinking of you): any info about oxygen permeability of beige 1/2" I.D. 3/4" O.D. "thermoplastic tubing" (Santoprene?) ?

I still have a couple of pieces I bought from Northern Brewer ~10 years ago. There's no labeling on the tubing that I can see.
Santoprene appears to be an EPDM-derivate that's used in automotive and industrial applications but not specifically for food processing, so I doubt you'd be able to find any that is food-safe and I certainly wouldn't use any tubing that is meant to go into a car for food processing... There are versions that are meant for the pharmaceutical industry that are probably safe for food processing but without labeling it's impossible to say if that's the case with the tubing that you have on hand.

I would just use standard EPDM tubing. I've been able to source it with 1/2" I.D. for my RIMS system so with a bit of browsing around you should be able to find it as well. It's most often used in milk and dairy processing so that's where you should start looking.

Regarding the unsealed container issue, I'm afraid that's going to be where most of your O2 ingress is going to come from anyway so you should really find a way of performing the transfer only between sealed and fully purged containers. The amount that will permeate even through the worst possible material (i.e. silicone) during transfer is still tiny compared to what you will be exposing your beer to if you let even a relatively small amount of a mixture containing 21% oxygen get into the keg.
 

Vale71

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I've probably got some vinyl that would work, but... I take it you're saying vinyl is much less oxygen permeable than silicone? ( though EVAbarrier is even better)

Sometimes, in pursuit of oxygen avoidance, I strongly feel the lack of solid data. Folks say, omg it made a big difference. But no one reports measuring dissolved oxygen. Just : my hop aroma lasted more / less. Sorry for the rant, and thanks for any ideas even when totally subjective 😁
The data is out there, even for very simple devices such as carboy caps:


FYI basically ANY elastomer is better than silicone. The permeabily of silicone rubber is just horrendous. It's so bad that gas exchange membranes in artificial heart-lung machines are made of... DRUMROLL ... silicone! :D
 
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sibelman

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Many thanks, @Vale71. I will read the Better Bottle material with great interest. Perhaps it will help me to develop more perspective on the comparative utility of different oxygen-exclusion methods. I've been focused on avoiding clogs, which have bollixed a couple of transfers in the last year -- hence my interest in fatter tubing.

From your remarks, I feel my biggest next move must be more effective serving keg purging. A few blasts of CO2 before transfer are clearly inadequate.

fwiw, Stout sells food-grade Santoprene. No reason I know to prefer that over EDPM from, say, McMaster-Carr.
 

Vale71

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fwiw, Stout sells food-grade Santoprene. No reason I know to prefer that over EDPM from, say, McMaster-Carr.
That's good to know. Unfortunately I'm located on the wrong side of the pond making ordering from them impossible so I'll have to stick to my reinforced EPDM tubing which has served me well even though it's a bit stiff and bulky.

As far as gas permeability goes Santoprene is basically the same as plain EPDM so if you have such an easily accessible source then you should definitely go for it. But do solve the open vessel issue first...
 
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sibelman

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@Vale71,

If I can avoid clogs with good cold-crashing and careful racking arm adjustment, I'll have no need to break the sealed path between fermenter and serving keg.

"...wrong side of the pond..."? Seems to me there's plenty wrong (and right!) on both sides of the pond. "...impossible..." You've already got the tubing you need, but (again fwiw) Stout appears willing to ship almost anywhere -- their web site's checkout page lists scores of countries, though shipping would likely be ghastly.

Thanks again for the advice, and all the wisdom you've shared here.

Cheers,
Steve
 

Vale71

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Stout appears willing to ship almost anywhere -- their web site's checkout page lists scores of countries, though shipping would likely be ghastly.
Shipping from the US to Europe has really become ridiculously expensive lately, to the point that it's only worth it for very expensive equipment that you really can't avoid buying directly from the US. Lately I've mostly been buying accessories directly from China, after all that's where 99% of the stuff is manufactured anyway. It's much cheaper but on the other hand shipping is really, really slow...
 

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Sometimes, in pursuit of oxygen avoidance, I strongly feel the lack of solid data. Folks say, omg it made a big difference. But no one reports measuring dissolved oxygen. Just : my hop aroma lasted more / less. Sorry for the rant, and thanks for any ideas even when totally subjective 😁
There actually are a growing number of brewers measuring DO at several points in their systems. It's somewhat annoying because you used to be able to pick up used process DO equipment cheap on Ebay, but no longer.
 

day_trippr

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I've probably got some vinyl that would work, but... I take it you're saying vinyl is much less oxygen permeable than silicone? ( though EVAbarrier is even better)
[...]
Sorry I lost track of this thread.
To the question: no, this is actually all about transfer rate. I use EVABarrier throughout the cold side of my humble brewery - every bit of beer and gas tubing - but for racking purposes I opted for the largest ID tubing that I could fit over a keg QD stem and the SS racking cane. 3/8" is geometrically much larger than 4mm (near 'nuff 5/16") cross-section area and thus flow-rate wise so in the end there's less exposure because the transfer is much quicker. Also PVC is easy to source and cheap to replace :)

Cheers!
 

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