The Tested and Proven Choice
There are many wine stoppers on the market today and all of them in one way or another try to emulate properties and characteristics that are intrinsic to natural cork. Those characteristics include the sensorial characteristics of cork’s look and touch, even the sound it makes when the bottle is opened; the environmental benefits of its 100% sustainability and recyclability; and its seemingly contradictory properties of being completely impermeable to both liquid and gas while at the same time allowing oxygen into the bottle.
It’s these last two properties that are of most importance to winemakers and at the same time impossible for other closures to achieve. They have been proven not only in the laboratory but also empirically – in bottles that have been opened after decades or even centuries and found to be unspoiled after being sealed with natural cork.
A Secret Within the Cork No Imitator Can Match
The problem for a closure is how to seal a bottle perfectly yet allow in just the right amount of oxygen. Wine needs some but not too much oxygen to develop; too little and the it suffers from reduction; too much and it oxidizes. Natural cork is made mostly of oxygen, and it is the oxygen it contains within its cells – diffused at a predictable but non-linear rate and in exactly the right amount – that interacts with the wine and allows the wine to reach its full potential. The classical attributes of fine wine that winemakers aspire to achieve – described in terms such as ‘balanced’, ‘complex’, ‘developed’ – have all been shown to be enhanced by the use of natural cork. Perhaps that is why the vast majority of the top wines in the world are sealed with cork.
The Qualities That Make Cork Special
Cork bark is 89% air, which is why it is so light. Its strength and elasticity is derived from its unique honeycombed cell structure, each cell of which does not break down even under compression, and returns to its original shape when the compression is removed. These qualities of lightness, strength and elasticity, along with its non-permeability, make cork an ideal material for a variety of applications in a multitude of industries, but especially for sealing a bottle of wine.
The Quality and Price Equation
If cork has been so perfect for sealing wine for centuries, why in the last couple of decades is there an industry of screw caps and synthetics made from plastics and bioplastics trying to engineer the oxygen transfer rates that cork achieves naturally? There are two main reasons.
The first is price. Natural products of higher quality tend to cost more, whether natural rubber vs. synthetic, diamonds vs. zirconia, or natural cork vs. plastics and screw caps. Imitators believe that if they can replicate cork’s functional utility at a cheaper price they can grab market share. And it is certainly true that many wines, especially those that are guaranteed to be consumed soon after production, do not require high-quality stoppers. But who can know how long a wine will be in transit, in a warehouse, on a store or restaurant shelf, or in someone’s closet before it is opened? In any case, the cork industry has raised productivity through better management of cork forests and more efficiency in the processing facility, thereby producing higher quality corks at more competitive prices.
Moreover, consumer studies show that wine drinkers are willing to buy more and pay more for wines finished with natural cork, negating any price disadvantage in the marketplace. Perhaps that is why even though cork is on average more expensive than other closures, it continues to be the leader in the market, accounting for 70% of all wine closures worldwide. Would a synthetic or screwcap at a natural cork’s price have any sales at all?
The Truth About Wine Faults – Oxidation, Reduction, Contamination, and TCA
The second reason is fear of TCA, a naturally occurring substance which, while not harmful to humans, can ruin the taste of wine. There is no question that years ago the incidence of TCA-tainted wine was at an unacceptable rate. But TCA is controllable, and the investments the cork industry has made in harvesting methods, storage, cleaning and testing, across all areas of production in the forest, warehouse and processing facility have brought those rates down to less than 1%. Some people still cite numbers like 5% or higher, but every laboratory test or blind tasting test proves them wrong and calls into question the motivation or recent experience on the topic of the person making the claim.
What’s more, faults in wine go far beyond TCA taint, and include permeable seals leading to contamination, leakage, and oxidation, and non-permeable seals leading to reduction. Further, TCA itself can enter wine from a variety of sources, not just the cork.