Drying is an extremely important part of the post harvest care needed to present a clean and tasty walnut. At home, place the walnuts on racks to dry and turn the walnuts from time to time. Make sure the racks are placed in an area open to air movement but under cover from rain or evening dew. A hot area with no air circulation will make the walnuts go mouldy.
Air drying on racks will take up to six weeks to be efficient. To check whether the crop is properly dry, open the shell and check whether the partition that lies between the two halves is brittle. If the partition is still soft and flexible it is unlikely the walnut kernel is properly dry. Another way to check is to taste the walnut. If the kernel flesh appears translucent or waxy, the taste is sour, strong or with a distinct after taste then the walnut is still not properly dry.
If you are drying your walnuts at home, the earliest date of delivery to the factory will be 1 June each season.
See detailed article on moisture in walnuts, on the NZWIG site
This is available to any supplier who wishes to make contact. The service requires the supplier to wash the walnuts first, dry the outside shells for two or three days, then get the walnuts, in onion bags, to the factory as soon as possible. Bags will need to be labelled with the suppliers name, and name of cultivar, where appropriate. Onion bags and labels are available from the factory.
As the harvesting period extends over approximately six weeks, suppliers may wish to stagger their shipments so that the walnuts can be dried promptly, soon after pick up.