Cork Quality Council 
Visual Grading Standards

Cork Quality Council 
Forestville CA
707-887-0141
info@corkqc.com


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CQC Members

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Corks Supply USA
Juvenal Direct
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and Capsule
M.A. Silva
Corks USA
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Comments or suggestions may be mailed to info@corkqc.com
    The following grading system has been adopted by CQC members to provide a common terminology in defining the visual grades of wine corks. 
Grade A

These are corks with top quality visual appearance - excellent surfaces, with no major visual flaws and few small ones.
  • No holes or pores which exceed 2mm. 
  • No cracks originating at the ends which exceed 11% of cork length.
  • No cracks in the body of the cork to exceed 18% of cork length.
  • All cracks must be tight and not open.
  • No horizontal cracks. 
  • No worm holes, hardwood, belly spots, or greenwood. 
  • Several narrow and shallow lenticels are acceptable if they are free of dust and particles.
Grade B

These are corks of good visual appearance with no major visual flaws and with surface visual flaws of no depth or substance.
  • No holes or pores which exceed 5mm. 
  • No cracks originating at the ends which exceed 18% of cork length.
  • No cracks in the body of the cork to exceed 25% of cork length.
  • All cracks must be tight and not open. 
  • Lenticels and horizontal cracks must not open up when ends of the corks are bent. 
  • No Greenwood. No angeled or deformed corks. 
  • Very small chips and lateral worm activity in the middle of the body of the cork may be acceptable. 
  • Lenticels at ends must not be wide or deep and should be free of dust and particles
Grade C

These are corks of average visual appearance with one or more major visual flaws which will be of cosmetic nature only. Thus they may be aesthetically unappealing, but functional.
  • No cracks, channels, hardwood or belly spots which exceed 55% of cork length. 
  • Lenticels and horizontal cracks on body may open up when ends of the corks are bent. 
  • Greenwood to 55% of cork length is acceptable unless severe depth or width. 
  • Large chips are acceptable. 
  • No worm activity from end to side which exceed 55% of cork length.
  • No dry years which exceed 55% of cork length. 
  • There may be heavy, but not continuous porosity.

To download this graphic please see visual grades.pdf

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Comments or suggestions may be mailed to info@corkqc.com