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.