Natural cork has been utilized for centuries to seal wine bottles, yet today there are popular alternatives made possible by newer technologies. This primer will keep you in the know about the best kinds of corks and why winemakers choose them.
The traditional choice for over 250 years, genuine cork expands and contracts inside the bottle and protects the wine in varied environments. Sustainably grown, cork is stripped from the outer layers of a living cork oak tree (it doesn’t harm the tree and the cork bark regrows). Its porous quality allows it to “breathe” with small amounts of oxygen that contributes to a wine’s potential to age.
“It is astonishing to see the human element that goes into each natural cork from the time it is harvested from the tree. Cork trees are very long lived—they can live on average 150-200 years—with an enormous capacity for regeneration. Cork is harvested at nine-year intervals. It is also 100% natural raw material, 100% reusable, 100% recyclable. The gradual evolution of wine in the bottle occurs in an environment with low oxygen, but with just the right amount to allow the wine to evolve correctly. The benefit of natural cork is that it’s 100% natural plant tissue consisting of a hive of microscopic cells containing a gas identical to air. It’s versatile and unique and a perfect choice for The Walls wines.”
Diam brand enclosures look almost identical to traditional corks. They are designed from wholly 100% natural cork that has been fragmented and treated with a patented steam process to completely eradicate trichloroanisole, known as TCA or cork taint, a natural compound that can impart musty flavors in wine. This advanced wine cork made in France combines some of the benefits of natural cork with the TCA-free qualities of synthetic alternatives.
Why winemaker and owner Chris Gorman of Gorman Winery & Ashan Cellars in Woodinville uses Diam cork composite:
“Diam, although made of cork material, is almost about the same as real cork. In theory, they breathe like a real cork…that’s their whole gig. So they can’t give you the cork taint, or the mold, because they are treated. And so I think they make my life easier because they age at the same level; there is a consistency in moisture among the corks, and in the structure of the cork itself, too. They are not as random as a naturally-made cork—this is a cork conglomerate and they are made to spec so they breathe at about the same level. I feel very good about putting them in my bottles.”
A state-of-the-art “green” alternative is this biodegradable, earth-friendly enclosure made by Nomacorc that is produced from renewable polymers derived from sugar cane. They are part of a larger family of enclosures known as synthetic corks that are made from a variety of materials.
Why winemaker and owner Ray Sandidge of C.R. Sandidge Wines in Manson, Wash. uses Nomacorc sugar cane cork:
“C. R. Sandidge has had success using a cork derived from sugar cane polymers for all of our wines except for the most expensive bottles. There are zero cork taint problems with this closure, and it is rated to protect wine for 8 to 12 years. It also has a zero carbon footprint.”
Made with a unique “breathable” aluminum design, wine bottle screw caps have long been the number one choice in Australia and New Zealand. They may not offer the appealing “pop” of traditional and synthetic corks, but their technology allows the lowest amount of oxygen permeation, resulting in a very high protection against wine oxidation. Stelvin was the first manufacturer to produce high quality screw caps capable of aging premium wines, but today there are many other brands available.
“At Co Dinn Cellars we use exclusively the Stelvin brand twist off to protect our wines. Many years of research, trials and over fifteen years of experience bottling and aging fine wines with Stelvin have convinced us there is no more consistent and ageworthy closure for white AND red wines. Adding in zero chance of TCA [trichloroanisole] or other off flavors from the closure, we are convinced that the Co Dinn wines you drink will age gracefully and taste just as the winemaker intended. The ease of opening is a bonus!”
Completely leak proof, glass corks like those made by Vinolok are crafted from pure Bohemian glass. They are fitted with an o-ring inner seal that allows the wine to breathe yet prevents any sort of oxidation to occur.
“Glass corks provide an airtight seal, are easy to insert and remove, and we never need to worry about cork taint. They are extremely convenient for a small winery because they can be inserted by hand. The limitation is that they require a bar top bottle made for the Vinolok. There are several bottle choices available but they do cost more than many bulk bottles. Our customers love them and tend to save them on their counters and reuse them.”