How to keep an open bottle fresh
Normally, a wine drinker only needs to think about the temperature for serving, which glasses to use and whether or not to decant, all of which are matters of personal preference.
But this simple state of affairs becomes more complicated if the bottle you have opened remains unfinished - especially if it's one worth keeping.
fact, the chemistry involved is pretty straightforward: oxygen is the single
culprit for a wine's deterioration after opening. Beneficial in small doses -
or even large ones for some wines - oxygen will progressively have a
deleterious effect on quality.
So, is there a single best way to preserve wine? To help me answer this, Decanter sent me six bottles of three different wines to test with a range of stoppers. Many products claim to keep wine fresh, but there are only two ways to do this. The most basic method is to put something in the neck of the bottle to prevent fresh oxygen getting into the wine. But this does nothing to prevent the oxygen already in the bottle from oxidising the wine, so the emptier the bottle, the less effective this will be. More complex innovations aim to remove as much oxygen as possible from the bottle before sealing it.
done either via vacuum or by adding inert gas to displace the oxygen and form a
protective blanket over the surface of the wine. There are several different
vacuum products on the market. Cheap and easy to use, they are a one-off
purchase. The disadvantages are that it will never be possible to remove all
the oxygen in the bottle and, in any case, the effectiveness of a vacuum must
be balanced against the harmful effect of submitting a wine to the violence of
the vacuum process. If a wine is 'over-vacuumed', its desirable volatile aromas
are literally sucked out.
One would imagine that using inert gas should give a better result, as this is
often used in wineries to protect wine during the winemaking process. This is a more expensive option, but has the advantage that it can be used in any container (such as a decanter).
For the experiment I chose three vacuum-style stoppers and two inert gas systems, along with the bottle's original stopper. Taking three contrasting wines, I opened six bottles of each, tasted them to ensure they were all consistent, recorded my notes, and then left them open for an hour to simulate a drinking environment.
The wines were each sealed with a different closure before being opened again 24 hours later, retasted, left open for a further hour, and then resealed. This process was repeated on 48, 72 and 96 hours.
The winesWither Hills Sauvignon Blanc, Marlborough, New Zealand 2007 (13% abv, screwcap) Bouchard Pere et Fils Fleurie, Beaujolais, France 2006 (13% abv, agglomerate cork) Clos de los Siete, Mendoza, Argentina 2006 (15% abv, natural cork)
Vacuum stoppers: 'Menu' Vacuum, Gard'Vin On/Off, Vacuvin
Gas stoppers: Private Preserve, Pek Preservino
impossible to say if any of the wine's original stopper was superior as, in
terms of how the wines developed, more seemed to depend on the wine than the
closure. But it's fair to say that all three original closures performed less
well than the manufactured stoppers, and for wines where preservation of the
original aroma is key, it's important to use a stopper that removes oxygen.
Sauvignon Blanc: After 24 hours there were clear and startling differences in the aromatic profiles of the six Sauvignon Blancs. Most noticeable were the variations in the wine's pungent, grassy aromas, which were most pronounced on the bottle resealed with the original screwcap, and almost absent from bottles sealed with gas. The latter had more delicate and floral aromatics. The vacuum sealed wines also had these floral aromas, but seemed to have developed more of green pungency than the gas preservers. The Sauvignon Blancs were pleasantly drinkable after a day, though the commercial stoppers all prolonged the freshness of the wine more effectively than the bottle's original screwcap.
The third and fourth day showed progressive deterioration of the wine. All but the screwcapped wine remained drinkable, but the bottle sealed with the Private Preserve gas cylinder remained much fresher than any of the others.
This crisp, lightweight wine with crunchy fruit was acceptable (even improved)
after a day's storage under all the alternatives, though the bottle resealed
with the cork was less fresh than the others. Although the fruit was still
vibrant, it seemed rounder and softer after 48 hours.
The best wines appeared to be those sealed with the Vacuvin and Private Preserve, and this was still the case into the third day.
By the fourth day, they were all tiring.
Argentinian blend: This big, densely coloured wine is high in alcohol and oak tannins. When first opened, its aromas ranged through oak, violets, coconut, black cherry, blackcurrants and spice. Although the wine tasted perfectly fine from all of the stoppered bottles on day two, it never regained the complexity of aroma or flavour of the first day.
The Private Preserve and Gard'Vin preserved the flavour and freshness best.
This limited trial shows that while there are significant differences in the stoppers' performance, all gave better results than merely sticking the cork back in the bottle or resealing it with its original screwcap. And while it's hard to come to any firm conclusions on which option (vacuum or gas) works best for which wines, the Private Preserve gas cylinder came out as the best way to keep our three types of wine fresher for longer.