The 2,4,6-trichloroanisole (TCA) remains a persistent problem in the wine industry. According to data provided by the Cork Quality Council (CQC), TCA affects 1 in 36 bottles of wine (2.8%) and is attributed to the cork stopper with a 95% confidence level. Wine Enthusiast reported in a May 2023 article that 3.5 to 6% of wines sampled in blind tastings are deemed to be contaminated by TCA or have a musty aroma profile. Thus, the problem of TCA contamination due to cork or cork-based stoppers in wines is far from resolved. This issue can be even more impactful depending on the type of wine.

Impact of TCA varies by wine category

Academic research on the impact of TCA on the sensory profile of wines shows that certain categories of wine are more affected by TCA contamination than others. White wines, unoaked wines, sparkling wines, and non-alcoholic or partially de-alcoholized beverages, commonly referred to as No-Low*, exhibit increased sensitivity to this contamination.

Sparkling wines are particularly affected by TCA

Studies conducted by the Comité Interprofessionnel du Vin de Champagne (CIVC) indicate that the perception threshold for TCA in sparkling wines is particularly low, at around 0.5 ng/L. In comparison, for still wines, the perception threshold generally ranges from 1 to 4 ng/L. The aromatic profile of sparkling wines is one of the main quality criteria, making it crucial to protect these wines from TCA-induced alterations.

No-Low: even lower detection thresholds

In de-alcoholized or partially de-alcoholized wines, which can be akin to aqueous solutions, the perception threshold for TCA is even lower, reaching values as low as 0.03 ng/L. Therefore, the complete absence of TCA is essential to preserve the aromatic profile of these types of wine.

Effects of cork taint

TCA inhibits olfactory signal transduction, thereby impairing the sense of smell. In other words, it interferes with the ability to detect aromas. High levels of TCA contamination result in a pronounced cork taint, characterized by an unpleasant musty, wet cardboard aroma. In smaller quantities, TCA diminishes the ability to perceive aromas, rendering the sensory profile of the wine dull and muted. An altered profile due to TCA can thus compromise the overall perception of wine quality, particularly in the case of sparkling wines and No-Low wines.

A Solution: choosing synthetic or screw cap closures

To avoid TCA contamination, it is crucial for producers of No-Low and sparkling wines to adopt TCA-free closure solutions. Synthetic corks and screw caps offer the most effective and reliable alternatives available. These solutions ensure the preservation of the aromatic qualities of every bottle.