Cork or plastic?

[luckyeight]

What are the merits or otherwise of cork and plastic for use in stopping wine?

[Ethel]

Cork is a natural, biodegrable resource but it can and does shrink ever so slighty in around 5% of all bottles of wine.

This causes the wine to taint - 'this wine is corked' - and become undrinkable.

Plastic corks don't have this problem and don't leave any residue or taste to the wine. It is getting more and more popular.
Sadly, plastic corks are not biodegradable and are harmful to the environment.

[Nemesis9]

I Just wanted to correct a couple of the details given in the previous answer.
The incidence of 'tainted' wine is nearer to 1 in 10 bottles, (10%).
However, and more importantly, 'taint' is not necessarily caused by the cork. The compound TCA that causes 'taint' in wine is commonly present in the environment, and although it 'can' contaminate the cork, it is also found in bottles, barrels, and the grapes themselves. Therefore, wine can be 'tainted' regardless of the closure method used. So tainted wine can be found in bottles using plastic corks (or screwcaps).

Additionally, Plastic stoppers have their own usage problems. Premature oxidisation and leakage are an issue, and can greatly reduce the shelf-life of the wine. There is also a mounting body of evidence that plastic stoppers can react with wines to alter the flavours.
So contrary to the previous answer, most vineyards (those producing premium wines at any rate) still favour cork.

[mccfluff]

what about screw tops? i heard these were ok but because of the snobbery factor they are not taking off. out of interest how does a screw top effect the wine?

[WendyS]

I bless the arrival of the screwtop wine bottle. At first I thought they were a real affront to wine but as I struggle trying to remove corks with a corkscrew I've decided they are the next best things to ring-pull cans.

[Nemesis9]

Screwcaps have been used increasingly since around 2001, and are predicted to soon become the main 'non-cork' closure method over plastic.
However they are no guarantee against 'taint' (see above answer) and require a manufacturing process that creates pollution, and is an energy drain.

The snobbery aspect is more consumer driven than winemaker.
Most New World wine producers, who make wines intended for immediate consumption are happy to use a screwcap, as any alteration in taste will take several years to manifest. Therefore the wine will have been drunk long before this would be an issue.
However, most wine drinkers assume that ALL proper wine should have a natural cork, and anything that does not is either, cheap, inferior or both.
Only wines intended to be 'laid down', and appreciated at a further date, years ahead, actually NEED natural cork.

[pagey3]

nemesis that's really interesting. I was of the understanding that wine makers were losing too much profit because of 'corked' wines so were converting to screw caps in an effort to minimise losses. but from what you said i guess this is wrong? is there any advantage to using a screw cap or is it just for mainline wines for immediate consumption?

[Nemesis9]

Your quite right in as much as the main driver for producers using screwcaps (and plastic type corks) is economic.
Natural cork is becoming harder and more expensive to source (Roughly half the worlds cork comes from Portugal), it can be inconsistent in quality, and is costly to treat in order to prevent contamination to the wine.

To clarify my earlier answer, although you can get 'tainted' wines that have been in bottles closed with a screwcap or synthetic cork, the problem is greater when using 'natural' cork if it hasn't been correctly sterilised, as it will encourage growth of a mould which will 'taint' the wine.
So for producers the screwcap, and plastic cork, are both cheaper to buy, and cheaper and easier to sterilise. Additionally they will also see a 'slight' reduction in the return of contaminated wines, making savings all round.

Currently, I understand there is a great deal of investment in other types of synthetic closure methods, but at the moment only 'natural' cork allows the wine to "live", breathe and mature in the bottle.

[luckyeight]

This is all really interesting - thank you all so much. Glad to see screwtops have also entered the discussion!