Cork vs. Stelvin: aging vs. reduction - the more I read the more confused I get

WINE TALK
1

I have done quite a bit of reading on the subject of cork vs. Stelvin closures. What tends to confuse me is that I read that many experts feel there is very little oxygen that gets into bottles through corks anyway. That school of though believes that most of the ‘aging’ of wine in bottles with corks occurs because of what’s already in the bottle when the cork is inserted.

Stelvin closures, on the other hand, can apparently cause something called ‘reduction’, which occurs when there isn’t enough oxygen in the bottle to retard the formation of hydrogen sulfide from yeast… at least that’s the shortened version as I read it here: http://www.winewriting.com/Screwcaps.htm" onclick="window.open(this.href);return false;

So… if very little oxygen gets in (when a cork is used), how does keeping it out (with a Stelvin) cause reduction?

Are we talking extremely minute amounts of oxygen passing through cork and contributing to aging, and to lack of the same small amounts affecting reduction?? Or is just the comparison of two theories that are not entirely proven either way.

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2

from the wineries that i have worked at that have transitioned to stelvin the reduction problem seems to be applying SO2 regimes that work for cork (30+ ppm) to stelvin where lower rates seem to be more appropriate.

count me as a believer in the fact that “good aging” (for want of a better term) is a non-oxidative process.

3

I’ve given up on the closure issue. The fact is that the wines I’ve already collected are in cork. At age 51 [cry.gif] and as someone who likes his wines with a decade or more of age on them the fact is that I simply won’t end up buying many wines that aren’t closed in cork… ever. I mean, let’s be optimistic and say I live to a healthy 85 and am able to enjoy wine until then… I’m not buying any significant amount wine past 60 or so… which is 10 years away. I don’t see the industry changing over that fast… so I’ve just come to the conclusion that the issue no longer affects me materially.

4

Peter, from my experience with screwcaps since 2004, as long as you choose the slightly “looser” saranex liner for your cap, there are no reduction issues (this is assuming the wine isn’t tending towards reduction anyway). Its the very tight tin liner which seems to be causing problems. A little O2 transfer (which the saranex liner provides) seems to be key.
Also, I can back up Andrew’s statement that wines under screwcap need far less SO2 at bottling, which is a good thing.

-Hank