Screw It

Natural Cork is the classic choice in the question of what goes between you and your wine. Cork bark is one of the few natural products that is malleable enough to hold the liquid contents inside a glass bottle.  The cork material enables wine to age without going bad in most circumstances. The porous material of wine cork enables tiny amounts of air to interact with the stored wine, helping it to age and transform in aroma and flavour.  The elasticity of the cork seals the bottleneck by expanding and ensures all liquid is completely sealed within the bottle.

In the past 60 years, several other wine closure options have entered the market.  Traditional wine corks remain the most popular option for modern wine brands.  Besides screw caps (made of metal and plastic), there are several ‘fake’ corks made from plastics to plant-based polymers.  There have been some surprising indications that shows how the corks vs screw caps argument is not as black and white as it seems. Which is the better alternative? If you say corks are better, one is both right and wrong. The truth is, the worldwide demand for wine (and corks) is growing, so we should get familiar with the future direction of wine preservation.

Screw caps have only been used in wine since 1964, but they have rapidly become a large share of the market.  A popular wine closure option in recent years in several countries, thanks to their unique benefits.  Screw caps offer little to no oxygen exposure, which is ideal for wines like Sauvignon Blanc, but not an ideal option for wines that are meant to age and develop over time. 

OR can wines age properly with Screw Caps?  Cork versus screw cap aging has passionate advocates on both sides. Cork proponents say that the interaction between wine and oxygen facilitated by the naturally porous material is essential to the aging process of a cellar worthy wine. Screw cap fans think otherwise, though neither side has proved their enclosure is better.  The long-time argument that natural corks are better because they breathe has been dispelled as such air interaction can now be emulated in both screw caps and cork alternatives. Today you can buy screw caps with calculated levels of ‘oxygen ingress’ overtime.  Ironically, real corks are actually quite variable with their oxygen ingress rates and no two natural corks are the same.

Some of the Pros to natural cork is that it is a renewable, recyclable, and a biodegradable wine closure.  Cork is the most traditional form of wine closure, with around 70 percent of all wines closed with cork seals. This statistic is even higher for fine wines.  This is in part due to the fact that high-quality natural cork imparts subtle and complex flavors to the wine as it ages.  Some of the Cons are that it is a Limited Natural Resource and it is susceptible to (‘Cork Taint’ a chemical called 2,4,6-Trichloroanisole or TCA for short). Corks also vary in quality and, last but not least, cost more.  100% natural corks are one of the only options that are a true renewable resource but because of their high price tag, most are reserved for wines in the $30+ bottle range.

Champagne and sparkling wine corks differ from traditional wine corks in the form of the cork disks at the bottom of the cork. These discs are more elastic, so when combined with the CO2 and six-to-eight bars of pressure in sparkling wine, they expand to form the mushroom-shaped cork we are familiar with today.

So, why choose a screw cap? Screw caps are easy to open and a more affordable option. Long-term aging studies have shown positive results and to the pleasure of many winemakers, no TCA (Cork Taint) occurs to the wine itself.

Conversely, the drawbacks to screw caps is that they are mostly made from Non-Renewable Resources, they are Recyclable but Not Biodegradable, and they are very often perceived and associated with cheap wines.

The debate of which is a better option will continue and thankfully the main focus remains about the liquid within the bottle.

As long as there is a desire for wine, the multifaceted balance of wine bottle closures will be an additional component to our collective enjoyment for many years to come.