Can that also be done in a tumble dryer?

Different ways to dry walnuts

So that the walnuts collected in September and October do not spoil, you have to dry them and store them optimally. Errors in drying and storage will immediately acknowledge the nut with mold growth. There are several ways to dry walnuts:

Air drying
Drying in the automatic dehydrator
Drying in a tumble dryer or oven

Harvest walnuts and prepare them to dry

The walnut harvest extends from September to October. During this time, the nuts fall from the tree and should be picked up quickly to prevent moisture from entering. Therefore, the walnuts must not be washed after they have been collected. Only remove the green cover if it is still stuck. If the nuts are dirty, all you need to do is brush them off with a vegetable brush.

Air dry walnuts

Store your walnuts in a dry place and let them air dry. While this method takes time, it is free. A dry, cool cellar is best for this. Place the walnuts on newspaper or a special drying rack and turn the nuts at regular intervals. The air can circulate around the nuts and after about 14 days they are dry.

Dry the walnuts in the automatic dehydrator

While automatic dehydrators have many advantages when drying fruits and herbs, they are only to be used in exceptional cases when drying walnuts.
Dehydrators work in a temperature range from 30 degrees. This temperature is too high for the oily nuts, they would go rancid. Only dry walnuts at low temperatures around 15 degrees.

Dry the walnuts in the tumble dryer or oven

The walnut oil quickly becomes rancid at higher temperatures and the nuts spoil. It is therefore not recommended to tumble dry walnuts or to dry them in the oven. The oven starts at 50 degrees, the tumble dryer is usually even warmer. At such a high temperature, only the nutshell would dry, the inner core would remain moist and mold quickly.