Some tips on how you can keep the contents of a bottle of wine fresh (see the video below).

It's always a dilemma you want to have a glass of decent wine but you don't want a whole bottle and then again you don't want to waste the bottle by opening it and not finishing it.

Start with a wee bit of science, as soon as you open a bottle it interacts with the air around. The great enemy of wine in many respects, especially aromatic white wines, is oxygen. Pour a glass out and leave it out for a couple of days and it will eventually turns into acetic acid, vinegar ! This reaction is sped up with heat so leaving it a warm area will get this result even quicker !

So the trick here is to limit the amount of exposure to oxygen the wine gets and keep it cool. I have over the years pick up a few methods some which work better than others and some which cost more than others.

1 - Buy a number of screw-top bottles (Amazon sells them) usually in a 250ml format. When you open your wine bottle, decant the wine into a couple of these bottles right to the top and stick them in the fridge. The process of decanting does introduce some oxygen into the wine but its better than leaving it in the wine bottle and in red wine cases will last up to 1 week. Cost £15 upwards for 12 depending on what bottles you choose.

2 - A productised version of this is the ETO wine preserver which is a wine bottle sized device that used a plunger mechanism to remove any excess air from the wine each time you take a glass. Again to maximise the effect of the device you should store it in a cool place preferably the fridge.

3 - Private preserve wine preserver. It looks like a can of hairspray and when you get it you wonder if there is anything in it, the can is so light. It is however filled with Argon, an inert gas (it doesn't react with the wine), and better still it's heavier than oxygen. SO when you open your bottle of wine you squirt a little of the gas into the bottle and because its heavier than oxygen it sits below the oxygen and forms a protective layer between the oxygen and the wine. Cost about £15 a can and can do up to 120 applications.

4 - Finally the Coravin, some say the professionals choice. Originally developed for high end wine bars where customers wanted to taste a top end wine but didn't want to pay the £800+ a bottle and the restaurant didn't want to waste the wine by selling it by the glass. Using the same argon gas technique the Coravin sits on top of the bottle of wine and has an inbuilt needle that pierces through the cork and whilst it extracts the wine it replaces the space with argon gas. The bottle remains intact and can be returned to the cellar. Coravin have released special screw-tops that you would replace the screw-top (quickly) of a bottle. The special screw-top has a membrane that the needle penetrates and operates in the same way. I have found that the cork reseal can be variable depending on what type of cork is in the bottle (different cork types are the subject of another story). Its not cheap but has come down in price recently to around £200. The refill argon canisters are around £6 and do about 20 glasses of wine. Whilst not cheap it is the device to use if you have many expensive bottles in your collection.