CQC Visual Grading Standards

The following grading system has been adopted by CQC members to provide a common terminology in defining the visual grades of wine corks. It has become a standard used by most wineries.

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.