Corks Don't Breathe

Discussion in 'Bottles, Labels & Corks' started by gamble, Feb 2, 2018.

  1. gamble

    gamble Member

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    This was from a winemakers blog from a real nice Michigan winery, I did not know:

    "Contrary to popular belief corks don’t “breathe.” According to Dr. Paulo Lopes and his studies on wine closures at the University of Bordeaux a natural cork is made of 80-90% air. It is the oxygen in the cork that is gradually released into the wine, usually over the first three years in bottle."
     
  2. Boatboy24

    Boatboy24 No longer a newbie, but still clueless.

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    Who knew? I haven't heard that one before.
     
  3. sour_grapes

    sour_grapes Victim of the Invasion of the Avatar Snatchers

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    gamble and stickman like this.
  4. balatonwine

    balatonwine The Verecund Vigneron

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    I also read this at:

    https://www.wine-searcher.com/m/2018/01/putting-a-cork-in-the-oxidation-question

    But to me these studies are all the wrong track and method, because they seem all so indirect and correlation based. And assumes a lot that we understand everything how wine reactions to O2 over time.... which we probably do not.

    Personally, I would design a radioactive tracer experiment. Bottles placed into a sealed, known external environment that is radioactive tagged. If O2 moves in at first, but then is reduced, or if from the cork only, this should be easy to demonstrate by the resulting isotopes decay results inside and outside the bottle over time.
     
  5. ibglowin

    ibglowin Moderator Super Moderator

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    Any volunteers to help @balatonwine pull samples? Anyone? Bueller? ....... Bueller?


    [​IMG]

     
    Last edited: Feb 6, 2018
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  6. stickman

    stickman Veteran Winemaker

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    I looked at that research paper and it doesn't appear to suggest that corks don't breath. They are just suggesting that the high variation of oxygen transfer rates reported for natural cork, is related to the raw cork thickness, which affects the cork cell structure, and internal volume. The logarithmic graph that is presented for oxygen ingress vs. time indicates that the oxygen ingress is high initially, then tapers off to a lower consistent continuous rate later in life. There have been studies previously conducted by others, that also suggested that most of the oxygen came from inside the cork, but they didn't analyze the data with respect to raw cork thickness etc.

    This type of information with so many details reinforces why winemakers tend to stick to what has worked for them in the past.

    I noticed there is no mention of the common practice of gassing corks with SO2; a fresh bag of corks from a supplier that uses SO2 (mine from Scott Labs smell like SO2 when opened the first time), probably contain a different amount of internal oxygen. I'm not suggesting that this is a big issue to worry about, all of us have bottled wine with corks not packaged with SO2, I don't even know if there is a significant difference either way, but just pointing out that when doing research, details like this have to be reviewed.

    I prefer doing my research by tasting........
     
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  7. Redbird1

    Redbird1 Senior Member

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    Interesting angle. There are so many variables that need to be considered.

    I think I've stated it elsewhere before, but a wine version of the Brulosopher would be great, but the long timeframes needed for wine vs. beer make it very, very difficult.
     
  8. sour_grapes

    sour_grapes Victim of the Invasion of the Avatar Snatchers

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    Unfortunately, there are no suitable O isotopes. The longest-lived, unstable O isotope has a half-life of 2 minutes.
     
  9. ibglowin

    ibglowin Moderator Super Moderator

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    Stop by sometime I will get you some Tritium and some proper PPE.....

    If you get contaminated you get to drink all the beer you want.

     
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  10. balatonwine

    balatonwine The Verecund Vigneron

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    I did not actually say to use radioactive oxygen isotopes, even if O2 is the element of "concern" that affects wine. Put extra C14 in CO2 in the surrounding case. It it enters the bottle, corks "breath". The amount of O2 transgress, I would argue, can then be accurately and directly calculated using side experiments that measure the CO2/O2 transfer rate ratio. :)

    Suggested radioisotope as was merely thinking it would be easier to measure the difference.

    One can even bottle an inert liquid (no interaction on anything that enters) in an inert gas (no oxygen at all) environment to improve measurement ability of what enters the bottle, but of course that adds a question mark about what affect wine itself has on cork permeability.

    One can also imagine, if wanting to use a tagged O, using instead a stable O18 isotope on the outside, similar as done in doubly labeled water experiments, if the rate of O18 ingress was sufficient to measure over time (but with a 100 year experiment, that should be enough time).

    Lots of options, which I think may be improvements on the current line of research. Because, subtracting measurable isotope cork sources, if there is more in the inside than that, it could only have come from the outside. If not, then corks don't breath.

    Of course all just a concept. Would all have to be worked out on paper for practicality.
     
    Last edited: Feb 6, 2018
  11. balatonwine

    balatonwine The Verecund Vigneron

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    The concentrations of radioisotopes would be low, it would not be a problem. It is not improbable, or even unlikely, you now have more exposure from the Radon in your home, than from this experiment. ;)
     
    Last edited: Feb 6, 2018

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