Storing half drunk bottles is something almost all wine lovers have to contend with. Often the wine left over is a result of enthusiasm/excess or simply because a single bottle is too much during the week. Nonetheless, keeping the wine as the winemaker intended overnight is no mean feat, given how rapidly a wine can degrade when exposed to oxygen.

The biggest enemy are the acetic bacteria often present and active in open bottles; these wines don’t oxidise in the chemical way, but generally rather more rapidly as the bacteria feed, turning your wine to vinegar.

The difference between the two types of degradation is fairly marked although both will be acting at once. Chemical oxidation will slowly turn your wine more stale, sometimes sherry- or Madeira-like, but overnight you should be able to reduce its progression to a degree where, for another night or two, it remains drinkable.

So, providing your wine is not too susceptible to acetic action, what’s the best way to maintain it’s freshness ?

I wish I had an easy answer – there simply isn’t one! There are many methods, each offering varying degrees of success. I think it’s so dependent on the type of wine – even on the character of individual bottles – that there’s no hard and fast rules.

However, I can clearly recall bottles, particularly young, tannic and or oaky wines, that actually drink better the next day providing their exposure to air is kept fairly minimal. I guess a wine decanted straight into a half bottle and placed in the fridge is perhaps less oxidised than a wine decanted for an hour or more in an open container, but it’s difficult to judge.

So, cards on the table, I think one of the most important devices to save wine overnight is your fridge! I have tried just about every wine preservation technique and no one method is best every time. The relatively undisturbed leftover bottle, placed into the fridge straight soon after opening works well in many cases. There exist devices designed to suck out the air first, but the problem with these is that while some wines seem to benefit this way, others turned out flat and dull. In some cases you can sometimes see the carbon dioxide being drawn out of the wine, which might account for the loss of freshness.

What about trying to avoid oxygen contact completely? Sounds like the ideal solution doesn’t it? Well, it isn’t. I was truly saddened to find an expensive device which pushes out and ‘preserves’ the wine under nitrogen made some irreplaceable wine react so badly to the gas that it was totally undrinkable next day.

So, with all my experience with the different devices and techniques on offer, what would I recommend ?

Red wines
If you know you’re only drinking a half, especially younger wines, try decanting immediately the half you don’t expect to drink into a smaller bottle and place straight in the fridge. Allow to warm up naturally within a couple of days.

If you didn’t know at the outset and are just left over with around a half or less, either lightly vacuum out the air and place in fridge or use a light layer of nitrogen (you might even want to try both together), and use the fridge or cool cupboard. It’s entirely possible that the fridge ‘shocks’ some wines and they don’t recover soon enough after opening to be an improvement over a cool cupboard, so once again experiment – and don’t expect all wines to react the same.

However, one hard and fast rule for me is with older, or just fully mature reds, avoid the nitrogen completely. You’ll also need to be careful or any heavy nitrogen exposure with any red – you can’t assume the results aren’t going to be better than oxygen exposure.

White wines including desert wines
Use the half bottle method when appropriate, but also use nitrogen more freely, including for the serving of the wine if you have such a device. Avoid vacuuming white wines unless you pump out air very lightly. In all cases continue to store in the fridge.

Port
I use the half-bottle technique usually, but don’t always use the fridge, even for more mature wines. They stand up well as a rule and the fridge can suppress the flavours for sometime after, although port served slightly cool on a hot day is a good way to continue your port drinking all year round!

Champagne
With Champagne (less so with New World fizz), believe it or not an overnight stay in the fridge with a normal cork placed in the bottle seems to work so well -- you’d hardly know it wasn’t just opened (we’re talking more than a glass or two left over). I suppose this is why people believe the silver spoon trick works – it’s perhaps because of the carbon dioxide forming a protective layer. However, if you think a spoon might help keep the carbon dioxide in the bottle, a cork certainly works a whole lot better!

But here’s the thing; when does anyone ever have any leftover champagne! C’est la vie!