Nut grading is the classification of kernels into commercial grades based on size, colour, whole-to-piece ratio and defect levels, directly determining suitability for end applications and the basis for price negotiation.
In trade practice
Graders use calibrated sieves and visual inspection to separate kernels by diameter and assess defects such as shrivelling, discolouration and insect damage. Buyers specify grade in the purchase contract, often referencing established trade conventions for the species, such as those used in the almond or walnut trade. A common mistake is accepting supplier grade certificates without independent pre-shipment inspection, which can result in off-grade material arriving at the processing facility.
In a specification
A contract specification typically states the grade name or code, minimum whole-kernel percentage, maximum defect tolerances by category and the sieve size or diameter range used for sizing.