How to cap a bottle of wine? Is a cork better or a screw cap? That discussion is not as black and white as it seems. Traditionally, wine bottles are sealed with a cork. But corks and the alternatives to cork are almost equal in terms of their ability to preserve and age wine.
Corks have been used to seal wine bottles since as early as 1400. It was at that time that glass bottles started to be widely used to store wine. Corks also allowed the wine to ‘breathe’. Nowadays, that can also be arranged with cork alternatives. And these days you can buy screw caps with calculated levels of ‘oxygenation’. On the contrary, the old-fashioned cork is the most variable in terms of oxygen uptake. One cork may oxidise more than another. After all, it is still a natural product.
Let’s take a closer look at wine bottle closures and the differences between corks.
Natural cork
This is the traditional cork extracted from the bark of the cork oak tree. Natural corks are widely used for sealing better wines: wines with storage potential. They offer a good seal and allow a very small amount of oxygen to pass through, allowing the wine to mature. In addition, natural corks are durable. In Burgundy, we see this type of cork a lot. Because of the high price tag, it is often reserved for the more expensive wines. For this classification, that higher price is negligible. It is often 20 to 30 cents per cork. The winemaker prints the name and/or coat of arms of the domaine on the cork and often also the vintage.
Technical – or compressed – cork
Technical corks are made of finely ground cork particles compressed into a cork. These corks are popular because they are cheaper than natural corks and less prone to defects. Technical corks also offer a good seal and allow a controlled amount of oxygen to pass through. One major manufacturer is Diam. This type of cork is also widely used in Burgundy. Technical corks are cheaper than natural corks and are gaining in popularity.
Composite cork
These corks consist mostly of compressed cork granules, but have a disc of natural cork at the top and bottom. Compound corks are cheaper than natural corks, and more expensive than technical corks. They are used, but not (yet) widely.
Plastic cork
A cork that looks like natural cork but is made of plastic. A plastic cork does not crumble and cannot give off a flavour either. Yet, this type of cork is considered very cheap. In particular, cheaper rosés quite often have such a seal. Plastic corks are a solution for wines that do not need to be stored for a long time. In Burgundy, you won’t see them very often. Plastic corks not only look cheap, they are.
Screw cap
This closing is not to be missed. It is quite often laughed at, but at the same time everyone understands its practicality. These metal caps provide an excellent seal and prevent oxidation and cork defects. Screw caps are cheap and widely used for wines that are drunk young and not meant to be stored for long periods of time. In Burgundy, the screw cap seemed to gain ground for a while. For instance, it was experimented with briefly in Chablis – including by larger producers. But it was not long-lived. In fact, you just don’t see the screw cap in Burgundy.
The choice of cork type usually depends on the quality of the wine and its intended storage potential. But of course, there is also a marketing component. A winemaker who wants to project quality will choose natural cork.