Evaluation of a Quality Control Tool for Predicting the Distribution of 2,4,6 – Trichloroanisole (TCA) in Cork Populations and Bottled Wines
2,4,6-trichloroanisole (TCA) transferred from natural cork closures to bottled wine was studied. The corks used in the study were all imported into California from Portugal. Ten different bales, provided by seven different cork suppliers, previously studied for their Releasable TCA (RTCA) in part one of same study, were used on a commercial bottling line with a California Chardonnay. After bottling, wine was stored under normal commercial conditions. After nine months, 100 bottles from each of the ten cork bales were opened and wine from each bottle analyzed for TCA. For each cork bale, the occurrence of bottles potentially affected by TCA ranged from 0 to 24%. These bottles were then sorted into categories, based on TCA’s potential sensory significance, including at sub-recognition levels. Percentages of “possibly muted” or “muted” bottles varied from 0 to 17%. Percentages of ?moderately corked? or ?corked? bottles varied from 0 to 7%. A relationship with bale RTCA scores, measured previously on group cork soaks from corresponding bales, was observed. Bales with the lower RTCA scores showed the lowest percentages of bottles potentially affected by TCA, while bales with the highest RTCA scores had the highest.
This study demonstrates clearly that cork’s RTCA is a good predictor of TCA transfer to bottled wine, at least within several months. It also shows that RTCA tests from group cork soaks, if applied in large scale QC programs, can reduce dramatically the occurrence of both ‘muted’ and ‘corked’ bottles in the marketplace.