CQC Audit Results - March 2013 |
Current Results from Screening of Incoming
Cork Shipments Show an 84% Reduction in TCA
Analysis of natural cork shipments continue to demonstrate a steady reduction in occurrence of the chemical compound associated with taint. Over the past nine years, the California based, Cork Quality Council has screened every shipment of natural corks its members have brought to their warehouses. Before CQC members accept any cork lot into inventory, screening samples are sent to ETS Laboratories for GC/MS analysis of 2,4,6-Trichloroanisle (TCA). |
Historic results show major reductions in TCA
Last year CQC members conducted over 24,000 analyses. Their combined screening records over the past nine years show a steady reduction in TCA levels that are now 84% lower than the results seen when records were first tabulated in 2001. |
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The CQC screening protocol receives data with minimum reporting limit of “<1.0ppt”. The group has agreed to treat results below the mdl as “0.5ppt” for statistical purposes. Under this assumption, the group’s statistical records cannot improve below 0.5ppt.
In the last reporting period, 94% of all samples from incoming natural cork shipments were tested at the <1.0ppt level. Another 5% had results between 1.0-2.0ppt. Approximately 3% of incoming natural cork lots were rejected by the CQC members prior to acceptance into inventory.
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Results from Testing of Technical Corks
Technical corks have been subject to requirements for chemical testing since 2007. Largely due to improvements in production methods —TCA results are now very similar to those levels seen in Natural Corks. |
Audited quality standards
The CQC conducts annual audits to verify that all approved QC protocols are observed. The foremost QC measure is screening for TCA, based on the GC/MS analytical method developed by ETS Laboratories. This analytical method is now widely used throughout the U.S., Europe, and Australia by members of both wine and cork industries. Other audited procedures involve moisture levels, physical integrity, residual oxidants and the maintenance of documentation. |
The CQC cork sampling program is rigorous
For a typical lot of 100,000 corks CQC guidelines require a minimum sample of 250 corks taken from a selection of at least five separate bales. These corks are placed in 50-cork wine soaks for 24 hours to extract releasable TCA. Resulting soaks are analyzed at ETS Laboratories using a method that reports TCA at concentrations as low as 1 part per trillion. If one of the five soaks indicates TCA as high as 1.5ppt – the entire cork lot is flagged and withheld from inventory.
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