INCOMING SAMPLING

Cork lots are received in units of 5,000 pieces. Fifty percent of containers received (or 10 containers per 100,000 corks) are sampled – 30 corks per bale.

Sensory Analysis Including GC/MS

• 100 corks per 100,000 received are soaked in 25 250 ml Erlenmeyer flasks (4 corks per flask). Each flask is filled with a neutral white wine, covered, and set aside for 24 hours. The wine is evaluated for aroma by a panel of at least three people. If TCA is detected in any flask, the four corks from that flask are re-soaked individually and again evaluated for aroma by a panel of at least three people. This allows for the determination of exact number of corks that don’t pass (see below for accept/reject criteria).
• For every100,000 corks received, three cork soaks of 50 corks each are sent to an independent laboratory for chloroanisole analysis (see below for accept/ reject criteria).
• Acceptance or rejection of a lot is based on the following point system:

For sensory, points are assigned as follows (average per 100 cork sample):

All corks pass: 0 points

1 cork positive for TCA: 1 point

2 corks positive for TCA: 2 points

3 or more corks positive for TCA: 6 points

For GC/MS, points are assigned as follows (average of all results):

< 2.1 ng/L TCA: 0 points

Between 2.1 and 3 ng/L TCA: 2 points

Between 3.1 and 4 ng/L TCA: 4 points

>4 ng/L TCA: 6 points

Lot passes sensory (including GC/MS) with 5 points and below or fails with 6 points and above. See scenarios below:

If a lot fails with the given point system it is re-sampled at the same rate of the initial incoming sampling. The second set of results is averaged with the first set. The lot is rejected if the average of the two sensory, together with the two sets of GC/MS results, fail the given point system.

• The above point system is the basis for sensory testing regarding TCA. However, any lot that exhibits strong objectionable aromas (petroleum/paint, sewer, etc.) greater than 3% will be rejected.
• NOTE: We also work closely with our clients to match their own Quality Control specifications. Every cork buyer is encouraged to discuss with one of our Account Managers to discuss their own unique requirements.

Grade

An optical sorting machine is used to sort and grade all incoming lots. The sorting process takes a wide, variable grade and sorts it into several narrow, consistent grades. This allows for greater control of grades with fewer variations in visual quality, which is used to satisfy clients’ requirements for quality and price.

Dimension

Length and diameter are measured using Mitutoyo digital calipers that read to 2 decimal places. Length is expressed as an average. Diameter is first measured parallel to the growth lines and then rotated 90º and then measured again. An average of the two measurements are given, which is then used to give an average for lot. The tolerance for length is +/- 1mm and the tolerance for diameter is +/- .5 mm.

RESIDUAL OXIDENTS

OENEO Closures tests all lots for residual oxidants using the method recommended by Codiliège. At time of shipment, the corks have less than 0.1 mg residual oxidants.

Supplier, OENEO Closures, provides a Certificate of Analysis with every incoming lot.