Storing Opened Red Wines

Yes. You can try vacuum devices or inert gases, but if it is for a few days most good bottles will handle it at STANDARD room temperature (if your room is at 30°C, it is not at room temperature...)

The refrigerator, as Mark will confirm, will increase the oxidation risk. Cool cellar temp fine, but not COLD.

Don't do that, no...

Sorry Mike, but this is contrary to common wisdom, my experience, and chemistry. Cool temperatures slows down oxidation.

M.

Keep int in the refrig and let it warm up to about 60 degrees before drinking.

It results that at 5 °C the oxigen content into water (or wine) is twice than at 20°C

Luk

Luk ha scritto:

Sorry not twice but a bit less

Luk

So what? Oxidation is the reaction of wine with oxigen, not the content in itself. Reaction *is* much slower at cooler temperatures.

M.

IMHO it is disputable if oxidation occurs at the wine surface because of enviromental oxygen or inside the wine when it absorbs oxigen. You are right, but it is also true that cooling wine it absorbs oxigen.

Luk

Just to shift a bit, here is a pearl of wisdom from Nicolas Joly (wee his site): "Wines produced by biodynamic agriculture don't suffer from oxydation". Wow ! ;-)))

Mark, we still await your verdict, does a cold half-empty bottle try to absorb the extra oxygen in the bottle, and if so does it cause oxydation? I thought it would.

There's a point at which one realizes that a major personal change has taken place. When I read this post, my reaction was Good grief, man, that's damn hot!"

Then I realized he was talking about Farenheit. And this despite growing up in the States and, for years, reaching for my calculator whenever anyone used Centigrade. Looks like my six and one-half years of living abroad have finally taken hold.

Jim

I am not a chemist, nor do I play one on TV. But I agree with Michael Pronay just based on anecdotal evidence - it seems to me that refrigerated half-filled bottles are less prone to oxidation than ones left on counter.

Uh huh. I actually find many of M. Joly's wines taste oxidized upon opening. The rep once told me "that's what Chenin Blanc tastes like" (my response was "not from Closel, Papin, Huet, Epire, etc etc etc).

Congratulations, you are now officially an outsider. Since you live in Tokyo at least they let you keep the housing deduction. (As of a few days ago, anyway).

Go Mets! ;)

-E

that's right, every second bottle seems to be that way. Not that I mind it that much, as it does not prevent the extraordianry evolution of a good year's QdS in the bottle as a meal goes on... However some vintages seem to verge on being off.

Pardon me Luk, but this does not hold water. Solubility of gases in a liquid does decrease with temperature (all other things being constant), but the rate of oxidation of an organic molecule increases with temperature (all other things being constant). One does not offset the other - the oxidation rate increases in spite of higher solubility.

And what we are discussing is oxidation of, not dissolution of oxygen in, the wine. Cooling wine (or any organic chemical) will make it less likely to oxidise - whatever be the solubility of oxygen in it.

Cooling will also make the mixture less volatile and certain "light" hydrocarbons in the mixture will not evaporate so easily. Depending on the wine in question, this may be a good or a bad thing of course, but is usually a good thing.

Also, the difference of solubility at 20 % degree Centigrade is probably 3 mg for half a bottle of wine. This small quantity is not going to oxidise the wine so very appreciably. I do not have a model which estimate oxidation rates of any organic chemical at various temperatures, but the impact oxidation has on the wine (reflected by change in odour, taste and sedimentation) is more in the deci- or whole grams order of magnitude.

Difficulty in oxidising hydrocarbons at low temperature is why one needs all manners of efforts to ignite car engines on cold morning.

Cheers

Wow, an actual chemistry discussion here. Let's see what I can add:

1. Yes, oxygen does have a higher solubility in cold water than in room temp water; that's why coffee should be made from cold water brought to near-boiling (it has the highest amount of dissolved oxygen).
2. The rate of oxidation of any substance in solution will depend on tepmerature, its concentration and the concentration of oxygen in solution, hence the relevance of solubility data. For the science wonks in the audience, the functional form is:

rate = k[organic][O2]

where k is a so-called rate constant specific to the reaction in question, and the brackets indicate concentration

1. rate also depends on the inverse of temperature, the functional form being:

rate = Ae^(-∆G‡/kT)

where A is a constant, ∆G‡ is the energy barrier (reaction-specific), k is Boltzmann's constant and T is of course temperature

1. The issue of oxygen solubility becomes virtually moot if one makes any effort to exclude oxygen from the bottle, either by evacuation or filling to the top, or blanketing with nitrogen, etc.
2. My own experience is that cooling the wine down does hlpe preserve it, but I usually take pains to exclude oxygen.

HTH Mark Lipton

I use a vaccuum pump, which will preserve the wine for a day or two quite well.

That semi-colon reminds me of the famous 'step 2: a miracle occurs' cartoon :). Why is coffee better when made with high dissolved-O2?

If every equation halves your audience, we're in trouble by now!

Note that theoretically*, your tastebuds are more sensitive at lower temperature, as their resting membrane potential is closer to zero (from the Nernst equation:

R T Extra_Con_i E = ----- ln( ------------- ) i z F Intra_Con_i

where T is the only variable of RT/zF). However, this is way more than cancelled out by (i) alterations in membrane fluidity, which are especially important in the nasal epithelium, and will reduce ability to respond to stimuli, and (ii) reduced volatility of the compounds which would otherwise bind at that epithelium.

OK, this was gratuitous. However, just back from the Neurosci meeting and having just taught sensory neuro, it was - warning, pun impending - on the tip of my tongue..

Because the characteristic aroma of coffee is produced by the oxidation of a thiol in the coffee, so one needs the dissolved oxygen to promote that reaction.

Great use of gratuitous math, Ewan, not to mention the puns!

Mark Lipton

(snip)

I have tried filling some screwcap 187 ml bottles with the freshly opened wine -- the idea being to fill to the point where the oxygen amount in the bottle neck is small. I've had mixed results, probably because of imperfect stopper seals -- can still tell the difference after a few days with a newly opened bottle. Anyone else tried this?

It's occurred to me that there's probably some way to refill a box wine bladder so that there's no air inside and reseal it, short of using a syringe like refilling an inkjet cartridge. Any thoughts on this by the inventive?

Zane