59. Corks, Screwcaps, and Surprises: How Wine Closures Affect What’s in Your Glass

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Episode Summary

This week we’re diving into a topic I’ve wanted to talk about for a while—wine closures. Whether you’re studying for WSET Level 3 or just wondering why some wines pop and others twist, this episode breaks down the major closure types, their pros and cons, and what they mean for wine quality and storage.

While this could easily become a deep dive (and I may still do that one day), today’s episode is an overview to help you better understand how closures affect the wine in your glass and what to look out for as a consumer or student.

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What You’ll Learn

• The difference between natural cork, technical corks, synthetic corks, screwcaps, Vinolok, and crown caps

• What TCA is, how it affects wine, and why it still impacts up to 2–3% of cork-closed wines

• The pros and cons of each closure, from oxygen ingress to perception and pricing

• Why synthetic corks aren’t recommended for aging, and how fast they let in oxygen

• Why screwcaps are often a better choice for fresh, young wines—and how liner options now offer controlled oxygen exposure

• What to do if you're storing wine at home—and how your closure type matters

• Real-world advice on how closures show up in blind tastings, and how they might influence your assumptions

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A Quick Snapshot

Natural cork is traditional and romantic, but still poses a risk of TCA (cork taint). Screwcaps offer a reliable, taint-free seal and are ideal for most young wines. Synthetic corks might look fun, but they allow a lot of oxygen in—and that’s not great if the wine’s been on the shelf for a while. Technical corks, like DIAM, use advanced cleaning processes to remove TCA, while Vinolok glass closures are beautiful but expensive. Crown caps are becoming more common in pet-nats and natural wines and are widely used during sparkling wine production.

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Final Thought

Closures are more than packaging—they’re a clue. They tell you something about the wine’s intended shelf life, how it was made, and even how it should be stored. Understanding the differences helps you buy better, store smarter, and taste more confidently. And if you ever doubted the importance of closures, remember: even the most beautiful wine can be spoiled by the wrong seal.

See you next time,
Joanne