When the nuts are gathered and brought in they are put into a revolving
barrel-churn holding about 12 to 16 gallons. Two buckets of water and
about the same of walnuts are put in together and the churn revolved for
some minutes. Then the nuts are taken out and spread on wire crates and
placed in the sun; they should be raked over two or three times a day.
Or, if the weather is wet, they may be placed in the dry-house in a good
draught at about 70 degrees F. In an artificial drying if the heat
becomes too great the nuts will be rancid, as the oil-cells will burst:
so better err on the side of underheating than overheating. If left out
of doors, cover carefully to protect from dew. The crates for outdoor
drying are placed on trestles in some California groves, in order that
the air may circulate through the nuts. This is much better than placing
them on the ground, where they draw dampness.