Last February, I went to the Irish launch of Coravin, a new wine preservation device, which promises to allow you to enjoy wine from the same bottle over a period of months, if not years.

Founder Greg Lambrecht became frustrated when his pregnant wife was unable to drink wine.

He couldn’t consume an entire bottle every night, and, in any case, he wanted a to have a glass of white wine, then one of red, and possibly a glass of dessert wine too. And so he started off on a 12-year process that was eventually to lead to Coravin.

He focused on how to extract the wine without introducing any oxygen. The answer is a very smart small piece of equipment that looks a little like a microscope, with clamps to grip the bottle, a long thin needle that pierces the cork, and a capsule of argon gas that automatically replaces the wine as you pour out the desired quantity through a spout. Once you remove the needle, the cork springs back to reseal itself.

It doesn’t work on screw caps or plastic corks, but apparently does with all kinds of cork. Coravin claims the wine will remain fresh indefinitely.

There are other wine-preservation systems, such as the Enomatic, but that is expensive and takes up a lot of space. The Vacu-Vin and related Verre de Vin systems work for a short period. Nothing else performs for as long or as reliably as the Coravin promises.

A wine enthusiast can now pour a glass of a particular fine wine, reseal it and then return for a second glass months later.

It will certainly be of real interest to those who like to have a glass or two of vintage port or dessert wine after dinner.

Restaurants can now offer a huge range of wines by the glass, including fine wine, without fear of being left with an opened, rapidly oxidising bottle. Wine shops can offer their customers multiple samples before they buy.

The big question, of course, is does it work? Jancis Robinson and Robert Parker are both fans. Château Margaux uses it to test their wines before sending them abroad for tastings.

Recently, I was invited to a follow-up tasting by Coravin agents. We blind-tasted the same resealed wines from February against freshly opened bottles. None of the journalists present were able to tell the difference, and we are not alone. Apparently, more than 2,000 professionals have completed a similar tasting, and none so far has a 100 per cent success rate.

The Coravin does have disadvantages. It is expensive to buy and does have operating costs; I found my argon capsule was good for about 15 bottles – that is 65 cents per use. It is also quite fiddly to use. I cannot imagine a sommelier bringing it to the table.

It would be great for restaurants that want to offer fine wines, even flights of a fine wine, or a glass of fortified or sweet wine at the end of a meal. But you probably won’t see it being used on the house wine.

I find a bottle of wine rarely lasts more than one evening chez Wilson, and you don’t need a seal if you drink any remaining wine the following evening.

There is also a strong argument that a bottle of fine wine, or any wine, is best enjoyed with friends and not kept for your own personal enjoyment.

However, my wife and I often enjoy a glass of white wine before dinner or with a starter, and then move on to a red. I can now crack open a very nice bottle and reseal it for a few weeks. So far it is proving very useful.

The Coravin is available through wineonline.ie and various retail shops including some O’Briens outlets for €299. Two replacement capsules cost €19.99 and each one works for anything from 15-30 glasses of wine.

This week, I recommend three expensive wines that might be best enjoyed by the glass.