Wine for Beginners: Clueless About Corks?

Let’s talk about cork... but not about the relative merits of different closures for bottles of wine. From the ancient world to the present day, no one can agree on the best way to stopper a bottle of wine so I will disregard the arguments and focus on the wine bottle sealing approach favoured since the 17th century – cork.

Why is cork used for wine?

So, why is cork such a craze? Well, it has all the properties needed to ensure the wine remains un-tainted by outside elements. It is flexible, light and impermeable. Three desirable qualities in a wine bottle stopper:

Flexible: A cork can be squeezed through the narrow opening of a bottle and then expand back into shape making sure that despite any irregularities in the glass, the bottle remains sealed.

Light: This means that it won’t eventually fall victim to gravity and drop down into the wine.

Impermeable: This means that nothing nasty can get into the wine, including air. Oxygen can be very damaging to wine – if air gets in, the wine will very quickly start tasting fairly lifeless although in very tiny doses it can make the best wines age beautifully.

Different types of cork for wine

There are lots of different types of corks but generally speaking, they fall into two camps. They are either:

1. Corks made from one whole piece taken straight from the bark of a cork tree, cut into shape, cleaned, sterilized and boom: it’s ready. This type of cork, a “natural cork”, suits wine intended for ageing. They can last decades so long as the wine is stored at the correct temperature and humidity levels.

2. The other choice is a “technical cork”. This is essentially lots of little pieces mushed together to form one whole cork. Technical corks can be fabricated from the cork of younger cork trees as the depth of the bark doesn’t have to be consistent. They are used almost 100% percent of the time in Champagne. Technical corks are cheap to make and suit wine that is not intended to age more than about five years.

How do they get the cork into the bottle?!

A very squeezed Champagne cork

I know the question on everybody’s lips is how the devil do they get them in?! Well, it’s easy! Cork is, as solid as it seems – a compressible substance. All you need is a machine strong enough to force it into the neck of the bottle.

In the case of Champagne and sparkling wine, things are slightly more awkward. A cork for fizzy wine is larger in diameter – it needs to be in order to withstand the pressure. The metal cage surrounding the cork is holding it in place. Without it, the cork would explode from the bottle – remember kids, more people are killed by champagne corks than poisonous spiders in the UK so only release the cage when the bottle is pointing away from your face (or the faces of loved ones).

What does “Corked Wine” mean?

Corks come with drawbacks. As it is a natural product, coming from all sorts of different trees from all different parts of the world, there will occasionally be a few which don’t make the grade. “Corked” wine essentially means the wine has gone off, and not that it has bits of cork floating around in it. It’s all to do with a chemical compound known as TCA which can infect corks. It makes the wine taste pretty dull in a sort of wet cardboard way. Don’t worry: however offensive to your taste buds, a cork-tainted wine won’t hurt you.

So hopefully you’re all experts now and can fight the corner for cork in any cork vs screwcap argument. Personally, I’m still on the fence...maybe I need more experience of aged Bordeaux under natural cork. Anyone want to send me some? A girl can hope.

Images taken from and Steve Hankin and Iwan Gabovitch's photostreams respectively in accordance with the Creative Commons License.