[tetrazine]

> Scientifically, this MUST be superior to simply replacing the cork (or screw cap in Australia).

Why must this be the case? This is a genuine question, not a pure objection.

Consider two oxygen levels, o_1 and o_2, where o_2 << o_1 due to vacuum removal. Consider a set of chemical reactions that occur between wine and the surrounding environment. Of oxygen, glass, trace chemicals, cosmic rays, astological auras, etc. Let ℜ be the set of chemical reations that affect phenomenological quality (flavour) (presumably negatively, as a just-opened bottle of wine is at the peak of quality and can only degrade).

Why must it be the case that o_2 is the limiting factor for all, or even some, of the elements of ℜ? What if another quantity (surface area, pressure, etc) limits the pace or extent of the reaction, and just as much degradation occurs with partial vacuuming (o_2) as without (o_1)?

Perhaps you or someone else is a wine chemist, professional or amateur, and can enlighten me. Until that point, there are more things in heaven and Earth, dear dhsysusbsjsi, than are dreamt of in your philosophy.

[arijun]

You’re 100% correct that it doesn’t have to be better, if gp was wrong about oxidization being the main issue. If the largest problem was evaporation of some oils or something, the vacuum would likely exacerbate the problem (imagine someone vacuum sealing a carbonated drink thinking it would preserve the carbonation!).

In the end, though, I think most people discover that those pumps do help preserve the wine for significantly more time.

[rprwhite]

Wine is a very reactive environment for oxygen. So oxygen will definitely be the limiting factor, because all the chemical reactions have been starved of oxygen (if you’re interested lookup the Fenton reaction). Of course, it’s not always that simple. If you have an very old wine it’s probably been oxidised, due oxygen ingress from the closure, in which case the vacuum is just sucking out the very small amount of remaining volatile compounds. Also, dissolved CO2 is very important in wine, even still wine, so if you have a light bodied, “fresh” wine vacuuming is going to lower the dCO2 - this will generally make it seem worse. Bringing it back to oxygen - increasing dCO2 can be used to increase shelf life, by decreasing oxidation, on wines where you want to limit use of SO2.

[stjohnswarts]

there are also lots of screw cap wines in the states and other places.