Corks have been the traditional choice since the 1400’s for preserving wine. Cork bark is one of the few natural products that is malleable enough to hold the contents inside a glass bottle. However, today there is great debate as to whether cork is actually the best way to preserve wine. The most prominent opponent is the screw cap.
The pro cork side of the debate usually begins with the fact that tradition dictates that cork is the way to go. It has been in use for hundreds of years. Screw caps on the other hand are a 20th Century invention.
For many of the more mature members of our society there is a sense of enchantment in maintaining tradition, including the ritual of uncorking a bottle of wine, which adds to the enjoyment and experience.
Cork bark is a natural ingredient, as well as a renewable resource. Cork is harvested from the bark of cork trees, which continually replenish themselves.
One of the properties of cork is that it does not have a completely airtight seal, which allows the wine to slowly oxidize in the bottle. This oxidization allows the wine to continue to age while it sits in the cellar, developing more complex flavours over time.
The down side of using cork is that cork allows cork taint, otherwise known as TCA or Trichloroanisole, a flaw that can happen when a wine is exposed to a particular yeast during production. If you’ve ever swirled and sniffed a glass of wine and smelled something like wet dog, then you have experienced cork taint. Because corks are permeable, bottles sealed by a cork can be vulnerable to damage.
Another downside to cork is the cost as cork is more expensive than screw caps.
Finally, there is the irritation you feel when the cork breaks off or crumbles into your wine when you try to open the bottle. To help prevent this from happening, the bottles need to be stored horizontally in order to keep the corks moist.
In the past, screw caps were associated with cheaper wines since they are less expensive than corks and were the obvious choice for budget-friendly wines. However, those days are long gone. Screw caps have their own benefits, so some high-end wineries have abandoned the cork. Some winemakers even prefer them to cork.
Screw caps do not allow TCA to occur in the wine after bottling. This doesn’t mean the wine is always free of TCA, since it can be exposed prior to bottling, but it does mean if it hasn’t happened before bottling there is no chance of exposure until it is opened.
Screw caps are much easier to open. A cork screw is not required so that means one less thing to pack when travelling.
On the down side, the airtight protection that is provided by a screw cap prevents the wine from breathing and slows down the aging process.
Also, while screw caps are recyclable they are neither biodegradable nor are they made from a renewable resource. They typically include PVDC plastic which is made from petroleum, making them a far less eco-friendly option.
Ongoing innovation in wine packaging means that natural cork and screw caps are not the only two options for bottle enclosure and storage. Plastic, can, cardboard and plant-based polymer cork are now being introduced into the marketplace.
While natural cork adds character, heritage and custom to your wine experience but is not necessarily a reflection of quality. Screw caps are a convenient modern option, but they have their own drawbacks.
You will have to decide for yourself which you prefer. Personally, it is the wine itself that determines whether I buy it, not whether it is sealed with a cork or a screw cap.