Following from a previous thread on PET versus glass, I observe that
the concensus seems on the whole to be thus:

Glass is better than PET for long term storage, because PET is felt to
be more permeable to oxygen than PET.

If that sums things up correctly, I would like to ask about the
following consideration:

Is it not the case that rubber is hundreds of times more permeable than
either, and thus the degree to which a long-term storage wine oxidizes
in the carboy is really not significantly altered by the vessel, since
most of the permeation of O2 is going to occur through the rubber?


Your thoughts?

Sean

>
> Is it not the case that rubber is hundreds of times more permeable than
> either, and thus the degree to which a long-term storage wine oxidizes
> in the carboy is really not significantly altered by the vessel, since
> most of the permeation of O2 is going to occur through the rubber?

I don't recall seeing any study that would confirm your assertion.

If it is true, though... regard the surface area where the permeability
would occur. 3-4 square inches at a bung, or massively more over the
surface area of a carboy.

Kirk

Fair point, but I suppose it depends on the ratio. I have emailed better-bottle to see if they have any more specific
stats for internal carboy surface area and 02 exchange across the PET material.

I can't help thinking that if the PET walls truly do suffer only 'negligible' 02 permeability, by definition they are as
low risk as using a rubber bung (which probably has greater permeability but lower surface area). Interesting thread
though

Jim


"Kirk Mitchell" > wrote in message oups.com...
>
>
>>
>> Is it not the case that rubber is hundreds of times more permeable than
>> either, and thus the degree to which a long-term storage wine oxidizes
>> in the carboy is really not significantly altered by the vessel, since
>> most of the permeation of O2 is going to occur through the rubber?
>
> I don't recall seeing any study that would confirm your assertion.
>
> If it is true, though... regard the surface area where the permeability
> would occur. 3-4 square inches at a bung, or massively more over the
> surface area of a carboy.
>
> Kirk
>

About as much permeability as a barrel? Less I think.


On Sun, 7 Jan 2007 15:37:49 -0000, "jim" >
wrote:

>Fair point, but I suppose it depends on the ratio. I have emailed better-bottle to see if they have any more specific
>stats for internal carboy surface area and 02 exchange across the PET material.
>
>I can't help thinking that if the PET walls truly do suffer only 'negligible' 02 permeability, by definition they are as
>low risk as using a rubber bung (which probably has greater permeability but lower surface area). Interesting thread
>though
>
>Jim
>
>
>"Kirk Mitchell" > wrote in message oups.com...
>>
>>
>>>
>>> Is it not the case that rubber is hundreds of times more permeable than
>>> either, and thus the degree to which a long-term storage wine oxidizes
>>> in the carboy is really not significantly altered by the vessel, since
>>> most of the permeation of O2 is going to occur through the rubber?
>>
>> I don't recall seeing any study that would confirm your assertion.
>>
>> If it is true, though... regard the surface area where the permeability
>> would occur. 3-4 square inches at a bung, or massively more over the
>> surface area of a carboy.
>>
>> Kirk
>>
>
The Anchorage Fishwrapper and Litterbox Liner Press

I hadn't even considered the permeability of barrels, good point


"A. J. Rawls" > wrote in message ...
> About as much permeability as a barrel? Less I think.
>
>
> On Sun, 7 Jan 2007 15:37:49 -0000, "jim" >
> wrote:
>
>>Fair point, but I suppose it depends on the ratio. I have emailed better-bottle to see if they have any more specific
>>stats for internal carboy surface area and 02 exchange across the PET material.
>>
>>I can't help thinking that if the PET walls truly do suffer only 'negligible' 02 permeability, by definition they are
>>as
>>low risk as using a rubber bung (which probably has greater permeability but lower surface area). Interesting thread
>>though
>>
>>Jim
>>
>>
>>"Kirk Mitchell" > wrote in message
groups.com...
>>>
>>>
>>>>
>>>> Is it not the case that rubber is hundreds of times more permeable than
>>>> either, and thus the degree to which a long-term storage wine oxidizes
>>>> in the carboy is really not significantly altered by the vessel, since
>>>> most of the permeation of O2 is going to occur through the rubber?
>>>
>>> I don't recall seeing any study that would confirm your assertion.
>>>
>>> If it is true, though... regard the surface area where the permeability
>>> would occur. 3-4 square inches at a bung, or massively more over the
>>> surface area of a carboy.
>>>
>>> Kirk
>>>
>>
> The Anchorage Fishwrapper and Litterbox Liner Press

yes thats really an excellent point...surely barrels are much much more
permeable than glass?


A. J. Rawls wrote:
> About as much permeability as a barrel? Less I think.
>
>
> On Sun, 7 Jan 2007 15:37:49 -0000, "jim" >
> wrote:
>
> >Fair point, but I suppose it depends on the ratio. I have emailed better-bottle to see if they have any more specific
> >stats for internal carboy surface area and 02 exchange across the PET material.
> >
> >I can't help thinking that if the PET walls truly do suffer only 'negligible' 02 permeability, by definition they are as
> >low risk as using a rubber bung (which probably has greater permeability but lower surface area). Interesting thread
> >though
> >
> >Jim
> >
> >
> >"Kirk Mitchell" > wrote in message oups.com...
> >>
> >>
> >>>
> >>> Is it not the case that rubber is hundreds of times more permeable than
> >>> either, and thus the degree to which a long-term storage wine oxidizes
> >>> in the carboy is really not significantly altered by the vessel, since
> >>> most of the permeation of O2 is going to occur through the rubber?
> >>
> >> I don't recall seeing any study that would confirm your assertion.
> >>
> >> If it is true, though... regard the surface area where the permeability
> >> would occur. 3-4 square inches at a bung, or massively more over the
> >> surface area of a carboy.
> >>
> >> Kirk
> >>
> >
> The Anchorage Fishwrapper and Litterbox Liner Press

Actually it's more complicated than that for a sealed barrel. The
barrel is semi permeable and it is now thought that it actually pulls
ambient air into the wine in tiny amounts because a vacuum is created
on tightly bunged barrels. They consider this micro oxygenation and
it's good for reds. As to whether a better bottle would emulate
that, I guess it comes down to surface area and permeability. To be
honest, I don't know if they think the air comes in from toppings or
through the staves; I have seen both stated. Smaller containers have
more surface to mass ratios, if you wanted to emulate anything i would
guess the 30 to 55 gallon barrels would be the ones to go for. Maybe
Google micro oxygenation and wine or barrels.

Joe