The outer green husk is removed by a huller and the nut is mechanically dehydrated (air-dried) to the optimum 8% moisture level. This prevents deterioration of the nut and protects its quality during storage. Walnuts are stored until needed for cracking. California walnuts are protected from contamination because of the nut’s double envelope of hull and shell while on the tree.
Walnut Packing
Walnuts are transported to a packing plant where they are graded into two distinctive markets, inshell and shelled.
In shell Walnuts
Following drying, sizing of the in shell nut occurs. Inshell walnuts are sized as jumbo, large, medium, or baby according to USDA standards.
Shelled Walnuts
Walnuts for both consumer and industrial use are removed from storage as needed and sent to the shelling department where they are mechanically cracked. The shelled material is screened. Kernels are screened into a series of sizes, air-separated from shells, and moved through electronic color graders and shell sorters.
Finally, they are hand-sorted by trained sorters and certified by for quality and USDA standards; then, they are ready for packing.
Once shelled, walnut kernels are physically inspected to ensure an end product that is clean, well-dried, and of specified color, as determined in comparison to the official walnut color chart.
Tolerances for total and special defects are specified for each grade. Laboratory tests, both chemical and microbiological, are conducted to meet strict regulatory agency and food safety requirements.