Keeping it fresh - making the best of leftover wine

For those who don't regard the concept of leftover wine as an oxymoron, it can be difficult to know what to do with that half bottle left at the end of a dinner party. The number of Australian fridge doors that feature bottles of sparkling with spoons poking out the top is testament to how little idea most of us have.

The main enemy to wine freshness is oxygen. A little bit can help a wine open up and blow off sulphur-type odours from just-opened bottles - the reason wines are decanted or allowed to "breathe" before drinking. But too much and the wine starts to oxidise, fruit flavours start to disappear, the wine begins to smell slightly nutty and eventually of vinegar. Whites take on a brown tinge, while reds lose colour and take on an autumnal hue.

The first step is, therefore, to minimise contact with the air. The simplest and cheapest way to do this is to keep a smaller container on hand. The headspace (the area between the wine and the bottle cap) is smaller, and therefore there are fewer oxygen molecules on hand to react with the wine. An empty half-bottle kept in the door of the fridge is very handy for this, although it is really only suitable if there's enough wine to fill it almost completely. Store the bottle upright to minimise the surface area of the wine that comes into contact with the air.

Heat also plays a part - any chemical reaction will occur faster at a higher temperature, so it's best to keep leftover wines in the fridge, even reds. Just take it out half an hour before you want to drink it the next day. And if it's still too cold, cup your hands around the bowl of the glass for a minute or so to warm it further.

Sally Humble, sommelier at Melbourne's Circa, sometimes uses such simple methods at home. "My mother came over a month ago and brought a $10 bottle of De Bortoli Windy Peak Chardonnay 2012, and we only had a glass, so I popped it back in the fridge, and then I went to cook with it well over a week later, and the wine looked fresh, just from putting the screwcap back on and keeping it in the fridge," she says.

Sally Humble, sommelier at Circa at the Prince, with their Enomatic machine which keeps wine fresh.

If you're willing to shell out to save your wine, there's no shortage of companies ready to take your money - most of them with questionable promises. A number of products promise to solve the oxygen problem by "removing" the air from the half-filled bottle.

Vacuum seals such as the Vacu Vin, or the $450 SoWine "Home Wine Preservation Bar", work on the principle of removing air from the bottle so that oxygen can't interact with the wine. While better than nothing, they're only slightly more effective than re-corking or capping the bottle.

A hand-powered pump, or even a mechanical one, can only remove a small proportion of the air in the bottle - just enough so the seal makes a "pop" when you open it again. There are plenty more oxygen molecules knocking about inside. Furthermore, even if they did manage to remove all the air and create a complete vacuum inside the bottle, the negative pressure would cause wine to evaporate to fill the empty space, resulting in a loss of aromatic compounds (the same reason winemakers fill their tanks to the brim).

A better option is to replace the oxygen with something else that won't interact with the wine. Argon, a "noble" (or non-reactive) gas, is popular with professionals.

Being heavier than air, a puff of argon squirted into a bottle will lie in a "blanket" over the remaining wine in the bottle, preventing it from contacting the air. Again, the bottle should be kept upright to minimise the surface area the gas needs to cover and thereby form a thicker barrier. Humble describes Winesave, a simple argon canister designed for home and professional use, as "ideal if you don't want to consume too much", and a recent article in the British press rated it the best of several preservation methods trialled by the author. At Circa, Humble uses an argon-containing Enomatic cabinet dispenser to keep by-the-glass wines fresh.

A puff of argon acts as a barrier between remaining wine and the air.

"The main reason is really to monitor pour levels, but it obviously serves as a means of preservation - it's about keeping people happy that when they order 150ml they're getting 150ml," she says.

If there's not enough for a glass or you don't think you'll get to drink it within a few days, you can always freeze it - not for drinking, but for cooking. Many recipes require little more than a glassful, and you may not want to rip the top off that bottle of 1991 Grange to marinate a lamb chop on a Wednesday night. Telly chef Nigella Lawson actually empties her guests' half-finished glasses into ziplock bags that she then freezes.

For home use, Penfolds winemaker Peter Gago says he often buys carefully selected 375ml and 750ml bottles, so seldom faces the problem of what to do with leftover wine. He has also used Winesave with success. Failing that, he recommends: "Immediately upon opening the bottle of wine pour approximately half the bottle quickly and carefully (without splashing) into a Schweppes 300ml tonic water bottle and quickly seal."

Spoon in a Bottle

With the exception of a friend's aunt who is known as "Flat Champagne Lorraine" for her habit of draining half-finished glasses of bubbles abandoned by other guests at weddings, the problem of how to keep the fizz in an opened bottle of sparkling is one that has troubled us all at some point.

Circa restaurant's Sally Humble dismisses the spoon-in-the-bottle theory as an "urban myth". While devotees of the method insist there's some sort of chemical reaction with the silver (if that were true, the silver would be visibly tarnished), Humble says it's "nonsense".

The key is to stop the gas escaping, and that can only be done with an airtight seal. Using the original cork is usually not an option - it won't fit back in the bottle, and reattaching the wire cage to hold it in there is very tricky. However, a seal such as the Champagne Stopper ($5 at Dan Murphy's) does the trick. The rubber seal is held in place by two hinged arms that grab the bottom of the glass ring that previously anchored the retaining wire.

While the carbon dioxide bubbling out of the wine offers some protection, oxidation is a risk, so another squirt of argon is called for.

Once again, heat is a factor - gas expands with higher temperatures, and so becomes less soluble in liquid. Those bottles of champagne being sprayed about on Formula 1 podiums are deliberately kept at room temperature to facilitate maximum squirtage.

But the more carbon dioxide that bubbles out of the champagne, the less there is to delight your palate when you want to drink it. So keep that bottle cold and the bubbles should still be there when your New Year's Eve hangover has finally worn off.

Source: The Australian, 15 October 2013