Here we are in 2018, 54 years since the first screw-cap wine was released—and somehow, people are still apprehensive about this alternative wine-sealing method.

At a recent wine-education seminar I was hosting, we did a side-by-side tasting of several wines. One of the first sets of wines we opened included a sauvignon blanc from New Zealand, and one from California. One bottle had a cork; the other had a screw cap. The purpose behind this was not to showcase closures, but rather to highlight the differences between the same grape grown in two distinct places. As soon as the wine was opened, one of the attendees announced that, clearly, the cork-finished bottle would be a higher-quality wine.

Wait … what? Are we still having this debate? Yes. Yes we are. Le sigh.

The truth is … I understand the attachment to natural cork. Hearing your wine crack open doesn’t quite have the same romanticism as hearing the gentle pop of a cork. But to suggest that good wine will only have a cork, and only cheap swill will have a screw cap, is a huge fallacy. Think of it like this: Just because Two-Buck Chuck has a cork, that doesn’t mean it is a good wine. And if it were finished with a screw cap, that wouldn’t make it any less desirable than it already is.

The real question lies in the cork itself. I suppose it’s easy to assume that all cork is created equal, and that when the foil capsule is cut away, if what you see looks like a cork, surely it must be cork, right? Uh, not exactly. I’ve found that most people are completely unaware of all the “manufactured” cork floating around out there. But just like a knock-off Louis Vuitton bag, if you look close enough, it’s easy to spot the imposter.

The reason natural cork has been the go-to sealant for about 400 years is because it has the flexibility and spongy spring-back to create a perfect seal. The goal has always been to prevent oxidation and have an impermeable barrier between the wine and the air. Corks, being the renewable and sustainable substance they are, became the Cinderella slipper—a perfect fit.

But real, natural cork is expensive, and the process from tree to wine bottle is laborious. The bark from a cork oak can only be harvested once every nine years or so. It is hand-punched from large, single planks, optically sorted and graded by quality. And even after all of the painstaking measures are taken to ensure a quality product, cork failure is still possible.

You might have heard your local wine nerd, aficionado or enthusiast talk about “cork taint.” If they’re getting super-nerdy, they’ll throw the acronym TCA around. In short, this is a result of microorganisms in cork feeding on naturally present chlorine and releasing a byproduct that smells musty, mildewy and dank. “Moldy cardboard,” “grandma’s basement” and “wet dog” are just some of the unpleasant aromas that a “corked” wine can emit. Other times, it can be so faint that even a trained sommelier can have trouble detecting its presence. But no matter the intensity, it will have an adverse effect on your wine. It can deaden the flavors and mute the fruit aromas—or be an all-out assault on your senses.

This is where corks become the bane of my existence. I put it into perspective like this: Let’s say you come to me looking for a suggestion on the newest, hippest, hottest wine. I gladly offer up a recommendation for a wine that is knock-your-socks-off good. You get home with said bottle, dinner cooking away on the stove, friends en route … when you pull the cork and pee-eww. This is one stinky bottle of vino. You’ve never had this wine before, so you’re not sure what it’s supposed to taste like, but you are pretty sure the stinky socks should come off before they stomp the grapes. So now what? If you’ll pardon the pun … you’re screwed. And for that matter, so am I. Chances are, you’ll never take another recommendation from me. If I think that was a great bottle of wine, clearly you and I have very different opinions on what good wine is. In addition, it’s pretty safe to say you’ll never buy a bottle of wine from that producer again. You obviously don’t like his “style.” So there you have it: I’ve lost your confidence and your business; the winemaker has lost you as a buyer; and you have nothing to drink with your dinner. Everybody loses.

This is where “pseudo” cork comes in. How do we give consumers the cork they crave without the taint that ruins everything? Agglomerated corks. In short, these are small, ground-down pieces of natural cork that have been washed and cleaned of any taint and glued back together using a food-grade polymer. Think of them as the particleboard IKEA version of a cork—inexpensive but effective, as long as you don’t plan on keeping it for a long time.

There are a few other cork-like closures, like colmated corks, which are made with low-grade natural cork, plus cork dust and glue used to fill in any gaps or pores—thus making the cork smooth, dense and better at creating that airtight seal.

Synthetic corks are basically plastic- or resin-based, and they are nothing short of terrible. Not only do they adhere to the side of the bottle, making them almost impossible to remove; they also breakdown quickly (sometimes in as little as a year!), allowing air to get in, and—even worse—wine to leak out.

A tiny percentage of wine is closed with a Vinolok. This is a glass stopper with an inert o-ring that is said to create a hermetic seal. While they look super-cool and do a fine job of preventing oxidation, they must be manually inserted (hello, labor costs!) and are very expensive.

That brings us to the screw cap. Ahh, my beloved screw cap. How do I count the ways in which you are perfection? No wine opener needed. No chance of TCA, cork taint, wet dog or moldy funkiness. Stelvin closures (the fancy-pants name for screw caps) create a perfect seal and keep the wine fresh for a long, long time. I know that when I crack open that bottle, it’s going to taste the way the winemaker intended, and if I don’t like it, it’s because it truly isn’t my style—not because I got that one bad bottle. It’s true the jury is still out regarding screw caps’ ability to age wine, and while they do prevent oxidation, they can also create the opposite reaction where they don’t let in enough air, creating reduction. But in my experience, this is very rare.

The point, my friends, is this: No closure is perfect. Everything will have its pros and cons. Cork, cork granules, glass, plastic or metal—it all has a place in the wine world. Remember, it’s what’s in the bottle that matters most.

Katie Finn is a certified sommelier and certified specialist of wine with more than 15 years in the wine industry. She can be reached at

Katie Finn drinks wine for a living. As a certified sommelier through the Court of Master Sommeliers and as a Certified Specialist of Wine, she has dedicated her career to wine education and sharing her...