I get asked about screw caps A LOT. If a wine has a screw cap, does it mean that the wine is cheap? Crappy? Should I steer clear of screw caps? Is cork better? My answer is that it usually does not matter if your wine has a screw cap or a cork. Here is a quick 101 Lesson on Wine Closures:
Natural Cork: Cork is the traditional closure found on a bottle of wine. Cork stoppers are made from the bark of a cork oak tree. As a general rule, the cork industry is considered sustainable and a cork stopper is considered the most environmentally friendly of all the stopper options. The trees do not have to be cut down or killed in order to harvest the cork. The cork is literally stripped from the outside of the bark of the tree. It then grows back and the process is repeated every few years. Cork closures are romanticized in the wine industry as opposed to screw caps. People look at a cork on a wine and get all warm and fuzzy inside. The wine opener has to be pulled out and the age-old process of opening a bottle of wine must commence. The downside of cork is that a bottle can get “corked”. Most people have heard this term, but don’t exactly know what it means. A wine that is “corked” or has the presence of “cork taint” means that there is TCA (which is a mold or fungus) present in the wine. A corked wine smells like wet cardboard. A wine gets “corked” when mold enters the wine’s environment. It can happen one of three ways: mold can get in the winemaking equipment, mold can get in the oak barrel, or mold can get in the crevices of the cork, as cork is a porous, natural material.
Synthetic Cork: There is also a synthetic cork made of plastic compounds that looks almost like a real cork. This material is not porous and therefore the possibility of having a “corked” wine is significantly reduced. The downside is the use of plastic and chemicals to make them. Some would say synthetic corks are not the most eco-friendly option. I don’t necessarily seek to avoid a synthetic cork (meaning that it’s not going to stop me from buying a bottle of wine), but it’s not something I like. Who wants plastics and chemicals all up in their wine?
Screw Cap: Aluminum screw caps are becoming more and more common. Aussie and NZ winemakers were the first to use them in quantity, and now you see them in more and more (usually New World) wines. Screw caps are great because they prevent oxygen from getting in contact with your wine. A screw cap will preserve the freshness and the the nose (i.e. the aromatics) of the wine, but it will not allow a wine to mature or continue to age in the bottle. So essentially, if a winemaker bottled and sealed a wine with a screw cap today, July 27, 2015, what the wine tastes like today, it will taste like forever. The screw cork will pretty much suspend the wine the moment it is sealed, and allow you to enjoy that exact wine (as it tasted that day) for much longer than a regular cork. The downside to screw caps is that they could subject the wine to reduction. Reduction is caused by the wines lack of contact with oxygen. Screw caps are obviously not porous, so they do not allow oxygen to pass to the wine. Reduced wine smells like sweaty onions or socks (no bueno) and is especially common in New World wines with screw caps. Decanting can help with slightly reduced wines.
My problem is that so many wines get better in the bottle, as wines are living, breathing things. That time in bottle allows the secondary and tertiary aromas to come through, which adds complexity and interest to the wine. If you’ve ever had an aged Bordeaux or a 20 year old Rioja that smelled like cigars and a musty basement, those were most certainly not screw capped wines. I advocate for the use of screw caps in wines that are deemed “drink now”. Wines that you are not going to cellar or hold on to for an extended period of time. Your clean, crisp whites, roses, and light, fruity reds are perfect examples of wines that would be just fine under screw caps.
At the end of the day, how many of us are seriously cellaring our wines or buying bottles that we need to hold on to? Like I mentioned in a previous post, most wines that people buy are consumed within 1 hour after purchase. If that is the case with you, the closure is not of utmost importance. But now you have the knowledge to make an informed decision. If you bought a Cuisinart wine fridge and want to stock it or maybe a friend just bought a house and has a mini-cellar that they’d like to fill up, you know to not buy any wines with a screw cap. You’ll be buying a wine that you want to age a bit, and hence you need a cork closure. But otherwise, eat, drink, and be merry!