Written by: KL TurnerNatural cork has enjoyed a long romance with the wine bottle. Over the past 250 years, corks have sealed many a high profile vintage in anticipation of opening night. The pop, the pour, and the pleasure all combine to deliver a great wine experience. Why is cork so beloved? And does anything else even come close to performing this essential wine task?Cork’s CharmCut from the bark of the Quercus suber oak tree, each natural cork is comprised of millions of flexible, air-filled cells. Each cork has a different makeup of cell sizes, shapes, and flexibility. On a microscale, that means every cork allows a unique amount of oxygen into the mix, giving each bottle of the same wine subtle variations in taste and style, increasing its complexity.Wines sealed with natural corks tend toward rounder, more complex aromas and tastes with less acidic palates. It is a generally accepted estimate that natural cork’s oxygen transmission rate, OTR, allows about 1 mg of oxygen into the bottle annually. That rate starts out higher, diminishing as the years tick by, while continuing to effect subtle, interesting, but unpredictable taste changes.Say It Taint SoCork works well, but then, there’s taint. TCA. Trichloroanisole. This flaw ruins between 1 and 2 percent of the wines produced with natural cork closures each year. Through the presence of fungi, a chemical reaction often attributed to the cork causes new compounds to form, imparting a moldy, damp, and generally unpleasant nose and palate that masks intended qualities. An accepted risk, cork continues as a major closure for big wines that spend a long time sleeping in the cellar.Screw It: Precision Without the PopEarly on, the screw cap translated to cheap wine. Goon. Plonk. This closure has come a long way since it first twisted onto a bottle, becoming the preference for some elite vintages. Surprised? Here’s why.Screw caps are manufactured to precise standards. Made of a tin or aluminum cap with a synthetic liner, this closure is designed to deliver a specified OTR. Predictable, consistent, and so far, untaintable some might say, the advantage of knowing exactly what to expect along the aging trajectory allows oenophiles to pinpoint the peak with accuracy.Screw caps tend to give wines a sharper, livelier palate compared to the same wine closed with cork. That can be great for a refreshing, crisp, fruity wine. Some do not favour a cookie-cutter taste, citing loss of variation compared to natural cork.Synthetic Corks: The Pop Plus TechnologySynthetic corks look and pop much like natural corks. Like other alternatives, they are manufactured with a range of specific OTRs, becoming a tool for vintners to stylize their wines with predictable results, playing with variations in the amount of oxygen dissolved in the wine.The winemakers know what to expect, and taint isn’t expected to be in the mix. That removes some of the risk for the consumer. Wines with these closures taste remarkably alike, from bottle to bottle, across the same wine.Stylish Glass: High MaintenanceAn elegant, expensive closure, glass stoppers with clear rubber gaskets make beautiful, near-perfect seals for wine bottles. However, as with any alternative stopper, anaerobic conditions excluding oxygen from the mix can lead to a rotten egg aroma, spoiling the taste of the wine. Additionally, these caps laugh in the face of bottling equipment, demanding hand installation and higher price. Still, they’re chic, and they keep wine very close to its bottled state, being good for fresh, crisp wines that will be consumed early.The Crown: Understated EleganceThe same top as that used on glass beer bottles, the crown closure has long been used during an intermediate step in the fermentation of Champagne. Usually replaced before shipping by a more traditional cork and muselet, some winemakers choose to skip tradition, sending important bottles to market wearing a little crown cap as opposed to a fancy cork with hardware.The taste is again dependent on the OTR, and the seal here is quite tight. Additionally, some argue that the pop of the cork is key to the wine experience, enhancing all tasting steps that follow. Lacking long trajectory results, there is only speculation, but results for this closure seem positive, even without the pop.And the Winner Is …Nope, not that simple. Natural cork is the preferred option for wines intended to cellar for long periods of time, allowing subtle variations in nose and palate with refined mellowing. Screw caps and synthetic corks are perfect for wines intended to be consumed early, providing great closure for fresh, fruity, wines with predictable nose and palate. Crowns and glass stoppers have little history to prove either way, so the jury’s still out.Each closure has its advantages and drawbacks, and technology continues to advance manufactured closures, more closely mimicking natural cork without the challenges. If I had to choose, I would choose cork, but that’s because I’m particularly fond of Bordeaux. And you?
