love_cab_chard
Master of Wine
Posts:12352
 | | 10/23/2003 12:51 PM |
| | Welcome, MarkusRandall all the way from Finland. Very nice. | | | |
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wineismylife
Arlington, TX
Master of Wine
Posts:12003
| | 10/23/2003 1:17 PM |
| | Markus, I don't know the answer to your question but thanks for your comments and welcome to VinoCelllar. | |
Joe
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Wine is like potato chips around me...if it's open, it's gone. | |
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TCK
Barrel Filler
Posts:1279
| | 10/23/2003 4:34 PM |
| | Actually, most researchers now believe that wine ages by releasing oxygen not absorbing it. This sort of reverse oxidation is the reason why wine doesn't taste stale as it ages. | | | |
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stemor
Collierville, TN
Wine Thief
Posts:2813
| | 10/23/2003 4:49 PM |
| TCK,
This is an interesting comment that you make, and I wonder if you can expand on it a bit or cite some reading material for me, as it has me scratching my head and rethinking to my chemistry days.
For instance, I'm wondering: Wouldn't it have to both release AND absorb oxygen? What compelling force would drive the equilibrium content of O2 down?
Usually, this would be impacted by increased temperature or a change in composition towards a solution that inherently retained less dissolved O2 in solution ... but that would seem to require a much more significant chemical change than anything that takes place inside a bottle of wine. | |
Cheers, y'all | |
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TCK
Barrel Filler
Posts:1279
| | 10/23/2003 7:13 PM |
| Basically it goes like this.
When wine is in the barrel it absorbs oxygen through the staves, then through the racking procces. This oxygen does infact mellow the wine and is thought to even out rough tannins.
In the bottle instead of absorbing oxygen the wine gradually loses it. During ageing the phenolics (Tannins, Pigments, and Flavor compounds) interact with the acid to form more complex flavor molecules - see why aged wine has less color and less tannin, they have become something else! At the same time the acid also causes the alcahol to react with the oxygen to form compounds called Esters and Aldehydes which add to the overall complexity.
Oxygen is one component of the chemical reation. As you can see acid is the secret to the whole thing and that is why flabby wines, while often rich and hedonistic in their youth often do not improve with age.
The theory is that while this happens - the oxygen that is in suspention is dissipating through chemical reaction - the wine may also react with the oxygen that is in the neck, and not in a good way. A half bottle has close to twice the air per wine as a 750 and 4 times that of a Magnum. That means more potential for oxidation. In 1863 Louis Pasteur did experiments with wine in test tubes that discovered that very little ammounts of oxygen exposure can greatly effect wine.
Bottle ageing is a slow process if more oxygen is present then is needed for the creation of the esters and aldehydes it will have an adverse effect on the flavor.
I got much of this information from the World Atlas of Wine, page 40.
TCK | | | |
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stemor
Collierville, TN
Wine Thief
Posts:2813
| | 10/23/2003 7:56 PM |
| OK, I think I see where you're going with that, but that isn't releasing oxygen as much as it is consuming oxygen.
Imagine a fish, constantly consuming oxygen in a lake and converting it into energy (and CO2 and CO). The lake doesn't become anaerobic, rather it constantly maintains its dissolved oxygen content by maintaining a relative equilibrium with the air layer above. The only way that the water's dissolved oxygen would drop is if the water 1. changed to some significantly different chemical composition, 2. got much warmer (and thus could dissolve less oxygen per unit volume) or 3. the oxygen source was reduced (the oxygen content of the surrounding air changed ... and if so, we've ALL got problems!).
In your analysis, the first two possibilities aren't really met (it's still an EtOH aqueous solution with suspended solids), so the only possibility would be that the oxygen content of airspace in the wine bottle changed composition, which would only happen if you had a seal that allowed no oxygen interchange.
If that's where we're going with this, then it's an argument that we are assuming a perfect seal ...thus, we don't need cork! Bring on the screwcap!
Uh, s rry for the thread drift. | |
Cheers, y'all | |
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love_cab_chard
Master of Wine
Posts:12352
| | 10/23/2003 8:06 PM |
| | I knew that TCK would come through... He is a wealth of Wine-knowlege. | | | |
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TCK
Barrel Filler
Posts:1279
| | 10/23/2003 8:54 PM |
| Stemor,
 on the screw caps  that's good
I think in your breakdown #1 is what is going on here. The oxyen is reacting to the acid and alcohol to form the esters and Aldehydes. Any additional oxygen exposure can cause premature aging of certain components and and oxidaton of the fruit and is therefore detrimental.
I'm no scientist, it's just what I have read.
LCC: Thanks | | | |
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ChangeMe
Grape Stomper
Posts:152
| | 10/27/2003 12:50 PM |
| Thankyou for welcomes and replies, all of you!
Had a busy friday and I try to leave the computer alone on weekends, so I'm a little late with my reply.
Quote:
In the bottle instead of absorbing oxygen the wine gradually loses it. During ageing the phenolics (Tannins, Pigments, and Flavor compounds) interact with the acid to form more complex flavor molecules - see why aged wine has less color and less tannin, they have become something else! At the same time the acid also causes the alcahol to react with the oxygen to form compounds called Esters and Aldehydes which add to the overall complexity.
Well, if the phenolics react with the acids in a reductive reaction, they loose the oxygen. But the esterification is then an oxidative reaction. But this, to me, makes bottle ageing look like a REDOX-reaction not just a reductive one. I had the idea that the oxidative reactions took place in barrel before bottling. 
This of course explains the effect of oxygen on ageing, but doesn't really make reductive the word for it, does it?
Sorry to bug you all.
Cheers,
Markus | | | |
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Pool Boy
Laurl, MD (DC suburb)
Master of Wine
Posts:13660
| | 01/19/2004 2:55 AM |
| I just wanted to thank those that took the time to post explanations of what port is and all the different varieties and all did so (JT, TCK, etc) -- I was trying to figure out what 'Ruby' Port was as we used a good bit of it in prepping the mincemeat for later use in the mincemeat pie we made a month ago. Hence, that does answer the question that I believe Frankie (too lazy to go back and look) asked -- do people cook with port. Well, yes we do. And Ruby Port is certainly cheap enough to not make you feel like crud as if you would if you were using some (expensive) vintage port.
Grazie! | |
www.roguefood.com -- www.cellartracker.com | |
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davidandrose
Aurora, CO
Grape Puncher
Posts:934
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NorCalVinoLover
Barrel Sampler
Posts:2200
| | 01/20/2004 3:53 PM |
| very cool link davidandrose, thanks
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DJ Hombre
Napa Valley, California
Barrel Filler
Posts:1360
| | 02/11/2004 7:37 AM |
| Vintage Port Question
I have a bottle of `85 Fonseca. What's the proper procedure to drink this? Stand up for a day or two, decant, pour? What's the general lifespan of an aged VP after you decant? Do they last overnight? | | | |
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KillerB
Barrel Racker
Posts:1533
| | 02/11/2004 11:30 AM |
| | First check for VA (Volatile Acidity) - 1985 is notorious, not sure abbout the Fonseca but lots of others have had problems. I'd stand for three days or so and decant - do not pour from the bottle: expect a mud-slide if you do. It should be fine the next day but wouldn't hold out for much beyond a couple of days. Please post notes when you're done. | | | |
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Pool Boy
Laurl, MD (DC suburb)
Master of Wine
Posts:13660
| | 02/28/2004 10:18 PM |
| | Question -- How do you pronounce Warre's? | |
www.roguefood.com -- www.cellartracker.com | |
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KillerB
Barrel Racker
Posts:1533
| | 02/29/2004 5:59 PM |
| | Like Warriors but without the middle 'i'. At least that's what everybody I've ever heard say. Could be wrong but as I'm the resident Brit and it's a British house - I win. | | | |
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Pool Boy
Laurl, MD (DC suburb)
Master of Wine
Posts:13660
| | 03/01/2004 3:35 PM |
| Quote:
Like Warriors but without the middle 'i'. At least that's what everybody I've ever heard say. Could be wrong but as I'm the resident Brit and it's a British house - I win.
So, kinda like -- "war-oars" or "war-ehs" -- just trying to determine if the Americanized pronounciation of warriors without the 'i' is what you're talking about or, most likely, the British pronoonciation...  | |
www.roguefood.com -- www.cellartracker.com | |
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