Corky oxygen

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winemanden

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Researchers from the Comité Champagne have conducted successful trials with oxygen-free corks. Their aim is to prevent oxygen from entering the wine from the corks. This is because sparkling wine corks consist of about 80 percent air. When they are pressed into the bottle neck, their volume decreases and the air pressure in the cork cells increases. This causes the air contained in the cells to diffuse into the wine. Whether made of natural cork or microagglomerate, the phenomenon is almost identical for all corks.

Benoît Villedey, deputy head of the wine department of the Comité Champagne, explains: "Within three months of the bottles being sealed, the cork releases 2.5 to three milligrams of oxygen into the wine. This sudden influx of oxygen can lead to undesirable oxidative ageing."

copied from "Wein Plus"
 
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I have a bit of trouble believing believing this study. A regular cork is highly compressed immediately prior to insertion into the bottle, and the air introduced into the bottle is what was in the neck as the cork insertion sealed it.

In contrast, champagne corks are huge in comparison to regular corks, which is what produces the characteristic mushroom shape. But the corks are highly compressed to get them into the champagne bottle, which crushes out the air. While it's possible the study is correct, it doesn't sound reasonable at first blush.

I am keeping in mind that regular cork insertion producers pressure in the bottle, which relieves itself in a few days. Which is why wine should be stood upright for a day or 3 after bottling. Given that champagne corks are so much more highly compressed it is possible that the air does not equalize.

I've also had 10 yo Champagne that was fantastic, so if the study is correct, does it matter?
 

hounddawg

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I have a bit of trouble believing believing this study. A regular cork is highly compressed immediately prior to insertion into the bottle, and the air introduced into the bottle is what was in the neck as the cork insertion sealed it.

In contrast, champagne corks are huge in comparison to regular corks, which is what produces the characteristic mushroom shape. But the corks are highly compressed to get them into the champagne bottle, which crushes out the air. While it's possible the study is correct, it doesn't sound reasonable at first blush.

I am keeping in mind that regular cork insertion producers pressure in the bottle, which relieves itself in a few days. Which is why wine should be stood upright for a day or 3 after bottling. Given that champagne corks are so much more highly compressed it is possible that the air does not equalize.

I've also had 10 yo Champagne that was fantastic, so if the study is correct, does it matter?
that's some mighty powerful thinking for a knuckle dragger like me,,,
just about my only thought is boy i bet Europe knew that a few hundred years ago,
Dawg
 

stickman

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I haven't looked at this specific study, but the general concept sounds reasonable, the cork cellular structure contains air that allows the cork to be compressed and rebound. Cork has been studied for many years, and some of the older studies suggested that the corks allow air or oxygen to pass through them, but more recent studies suggest that the air is contained in the cork cellular structure, and once this is depleted very little air passes through over time. I have also seen studies that indicate agglomerated cork contains less oxygen than natural solid cork, and even the top Reserva Nomacorc uses inert gas instead of air for the foam blowing agent.

I think this is less of a concern for red wine, but for white wine, rose and champagne etc. it is more of a concern. With home winemaking it is usually common to handle the anticipated additional oxygen from a cork and headspace with an additional 6 to 10ppm free SO2 above your bottling target. Professional winemakers have more resources and are always looking at the details, in this case, to reduce oxidation and resulting bound SO2.
 

winemanden

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I just put this on here as a matter of interest. I quite agree, does it really matter to the average drinker; is there such a person? Maybe for vintage Champagne perhaps. My own thinking is that they may be worried that the quality of cork they are getting now is not as good as it used to be.
It doesn't matter to me, as the only time I drink Champagne is if it's free! It's nice but not worth the Hyped up price they charge for it.
 

Rice_Guy

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*My calculation from measuring volume is that with one inch ullage there is enough oxygen in the compressed head space to saturate 750ml of wine with oxygen. The ullage using a natural pressure corking head is compressed to at about two atmospheres of pressure inside the bottle. ,,, This seems to be much of the science behind bottle shock.
*Industry folks fight the head space with techniques as dropping liquid N2 in the bottle or pulling a vacuum before cork insertion. Here at home I am using a vacuum head for corking.
* Natural cork is porous and has measured gas transmission ALWAYS, at one day as well as ten years. This is part of the logic of standing natural cork upright for two days, then lay flat. Synthetic corks are electrically etched so they have oxygen transmission similar to natural. There are better grades available(Reserva) which have reduced transmission for long term storage. Metal lids with Saran inserts are the best that is currently on the market/ have the lowest transmission. The AWRI has studies/ data on the web.

Researchers from the Comité Champagne have conducted successful trials with oxygen-free corks. Their aim is to prevent oxygen from entering the wine from the corks. This is because sparkling wine corks consist of about 80 percent air. When they are pressed into the bottle neck, their volume decreases and the air pressure in the cork cells increases. This causes the air contained in the cells to diffuse into the wine. Whether made of natural cork or microagglomerate, the phenomenon is almost identical for all corks.
It would be nice to see the French data. Vinventions which sells several grades of synthetic cork also sell a light pulse based sensor to monitor oxygen content without disturbing the wine.
 

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