109. Cork Taint Explained - What Corked Wine Actually Means and How to Identify It

Host: Joanne Close Episode Length: 13 minutes 12 seconds Release Date: April 30, 2025

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Episode Description

Cork taint is one of those wine faults that everyone has heard of but very few people can confidently identify. In this episode Joanne finally tackles a topic she has been putting off covering, and it turns out to be one of the most practically useful episodes she has recorded. Whether you are a WSET student who needs to know this for your exam or simply someone who wants to know what to do when a bottle does not smell right, this episode gives you everything you need.

Joanne starts by clearing up the most common misconception, which is the difference between a wine that has bits of cork floating in it and a wine that is genuinely corked. From there she walks through the chemistry of TCA, what it smells like, why some people detect it more easily than others, and exactly what to do if you suspect you have a bad bottle. She also covers where TCA comes from, why it is not just a cork problem, and what the wine industry has done over the past few decades to reduce its occurrence.

This is also one of those episodes where Joanne's practical storytelling is at its best. You will hear about her parents' kitchen cabinet, baby carrots cleaned with bleach, a winery that lost an entire vat of wine to TCA contamination, and a surprisingly useful tip about what to do with a corked bottle if you cannot return it.

What You'll Learn in This Episode What Corked Actually Means

• The difference between bits of cork in your glass and a wine that is genuinely corked
• Why finding cork fragments in your wine does not affect the taste and what to do about it
• Why the term corked refers specifically to TCA contamination and nothing else

Understanding TCA

• What TCA stands for and why we use the abbreviation
• How TCA is described in the WSET textbook and why you need to know it for your exam
• The key aromas associated with TCA - wet cardboard, damp basement, wet dog, mouldy newspaper, and autumnal notes
• Why the amount of TCA in a wine can vary from obvious to extremely subtle
• Why a subtly corked wine can be particularly damaging because it dulls fruit aromas without being immediately obvious
• Why some people detect cork taint more easily than others and why this is completely normal

How Sensitive Is Your Nose

• Why the detection threshold for TCA is measured in parts per trillion
• How to put that sensitivity into context - one second in 32,000 years, or a few drops in an Olympic swimming pool
• Why CO2 in sparkling wines makes TCA easier to detect

Where TCA Comes From

• Why TCA needs phenols plus chlorine to form
• Why natural cork is the most common source but not the only one
• How wood pallets, barrels, and even the architecture of a winery can harbour TCA
• Why wineries avoid bleach-based cleaning products
• The banned chlorophenol fungicide once used on cork trees and why its residues are still causing problems decades later
• Why TCA is not limited to wine, with examples from carrots and kitchen cabinets

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