CQC Quality Standards

FOR INCOMING CORK SHIPMENTS 

I.   SAMPLING PLAN

Individual lots of corks should be sampled using the ISO-2859-1 Inspection Plan (US Military Standard 105-D). Depending on the unit of inspection, the sampling is applied to either the number of bales in a single cork lot or the number of total corks in the incoming lot. All incoming cork lots must successfully pass through inspection before they can be accepted into a CQC Member's inventory.

II.  ACCEPTANCE/REJECTION

Guidelines for acceptance and rejection follow the ISO-2859-1 Inspection Plan at the various acceptance levels as indicated per the tests listed below. Acceptance is on a Lot basis, and nonconforming results cause the entire cork lot to be rejected.

III. TEST PROCEDURES

  • Chemical Screening for TCA (Required for Natural Corks)
    The number of bales within an individual cork lot is in accordance with ISO-2859-1 General Inspection Level II. Fifty corks from each selected bale are immersed in a 1.5L container of neutral dry white wine for 24 hours. The soak solution is screened for chloroanisole concentration using GC/MS (SPME) analysis on CQC equipment operated by ETS Laboratories. Acceptance is based on an AQL of 2.5. Non-conformance of any Lot requires either an immediate rejection or an expanded sampling at the General Level III. Any lot failing to comply with standards in the second sampling will be rejected and withdrawn from the CQC Member location. Acceptance is based on the AQL 2.5 applied to either the second sampling or a combination of the first two analyses.

  • Chemical Screening for TCA (Required for Technical Corks)
    Procedures are the same as performed for Natural Corks, but at a reduced sampling level that recognizes the significantly lower variation between corks within an individual lot for this type of cork. The number of bales within an individual cork lot is in accordance with a custom sampling schedule that for initial inspection is a combination of ISO-2859-1 Special Inspection Levels 3 and 4. Any subsequent re-sampling requires an accelerated sampling schedule based on the General Inspection Level I.

  • Moisture
    Cork moisture is tested based on the total number of corks within an individual lot. Samples are selected based on ISO-2859-1 Special Inspection Levels 3. Moisture results are determined by an approved electronic moisture meter. Acceptance is based on either the mean of samples below 7.0% or that the number of samples >8.0% is within the tolerances of AQL 4.0.
If moisture level does not conform to standards but the average is below 10.5%, the following remediation actions may be followed:
    • Corks are to be placed in a drying area which is physically separate from the storage area for accepted corks.
    • When corks are re-sampled for reduced moisture levels, the cork moisture will be retested under the original requirements.

  • Dimensions:
    Cork dimensions are tested based on the total number of corks within an individual lot. Samples are selected based on ISO-2859-1 Special Inspection Levels 3. Dimensional measurements are determined using an electronic or dial caliper accurate to +/- 0.01mm. Tolerance ranges are per ISO-3863 and acceptance at ISO-2859-1.
    • Diameter: as specified (+/- 0.50 mm) AQL = 1.5
    • Length: as specified (+/- 1.00mm) AQL = 4.0
  • Residual Oxidants:
    Residual oxidants are tested based on a minimum sample of three corks per lot. Measurements are determined using an approved chemically treated strips based on the Peroxidase transfer of peroxide oxygen to an organic redox indicator. Approved strips must have a minimum reaction zone of 1mg/L. The combination of corks and soak volume must create an MDL below 0.2mg/L/cork. Lots are marked for remediation or rejection if there is any positive response.

IV.  LOT DEFINITION

A lot is defined as a particular wood quality, size, and wash from an individual supplier in a single shipment. Sampling for chemical testing by SPME requires a maximum lot size of 400,000 corks. Larger lots will be divided into subsections below the maximum levels.

V.   RECORDS

Permanent records of the quality control tests for each lot will be kept by the Supplier for a period of at least five years.

 



FOR OUTGOING SHIPMENTS          

I.  TEST PROCEDURES
    • Batch Quality
      The batch quality should match any samples presented to clients on which the order was based. Cork samples sent to a client should contain a minimum of 24 corks.

    • Cork Moisture
      Randomly sampled corks from the prepared batch are analyzed using the sample procedure outlined in Incoming Cork QC. Prepared batches should have an average moisture range between 4% - 8%.
    II.  RECORDS

      Permanent records of the quality control tests for each lot will be kept by the Supplier for a period of at least five years.

      III. GENERAL

      Every reasonable effort will be made to ensure the pristine character of the corks is preserved while in processing at members’ facilities.


      11/01/2016