Mark Lipton wrote:David Z wrote:I'm surprised so many people are pouring off into 375s...I would have thought the added benefit of minimizing surface contact with the air would be outweighed by the dissolved O2 you introduce into the wine via the pouring process.
You need not introduce much O2 when you pour off the wine. If you smoothly decant into the 375 the liquid is flowing with what the experts refer to as laminar flow. In that case, turbulence is minimized and there is little oxygen ingress into the wine. For the really paranoid, you could purchase a fish tank aerator, connect it to a bottle of nitrogen, argon or (better yet) helium and sparge your wine briefly with the inert gas, then seal the bottle. Too much work for me, though. To avoid all that work, I'd just drink the wine instead
Mark Lipton
Ok, so here's my question. There are obviously several chemical and biochemical reactions taking place as the wine is exposed to air.
First off you've got the standard issue oxygenation reactions. What's the reaction rates on those? Do tannins protect the wine? Are any of the volatile aromatics oxidized and destroyed? Are the reaction rates highly temperature dependent?
Then you've got loss of volatile compounds to the air-- presumably some sort of equlibrium is reached w/r/t the volatiles and the air in the bottle, and when you introduce new air you lose some volatile esters and such.
Lastly you've got the biochemical reactions. Presumably as soon as the bottle is opened you're giving Acetobacter a foothold in the wine, and VA starts to go up. How fast does this happen (obviously depends on the pH of the wine, inter alia), and how temperature dependent is this process?
If the oxidation reactions are relatively slow (and my understanding is that they are, and that some might be desirable in that a lot of reductive compounds are removed from the wine), is fridging it really going to matter? We're talking a 30 degree temperature difference--its been awhile since I took P-Chem, but I can't imagine that is going to affect reaction rates too strongly. On the other hand, bacterial growth rates are highly temperature dependent, and fridging a wine should strongly reduce the production of acetic acid in the wine. Along those lines, I wonder if a drop of sorbate might do wonders to preserve a wine after its opened.