Mushroom grading is the classification of fruiting bodies by cap diameter, colour uniformity and veil condition into defined commercial grades that determine suitability for retail, food-service or processing channels.
In trade practice
For fresh and dried mushrooms, graders work to written specifications that define cap diameter ranges, acceptable colour bands and maximum defect tolerances. Inspection is carried out on grading belts, with supervisors taking periodic samples to verify conformity. For dried product, moisture content is checked alongside physical grade, as high moisture can mask weight and affect shelf life. Buyers commonly reject lots where the veil has opened beyond the agreed grade, reclassifying them to a lower-value flat or processing grade.
In a specification
A specification states the grade name, cap diameter range as an indicative figure, maximum percentage of off-grade pieces by count or weight, and the moisture limit applicable to that grade.