Undesirable surface hardening of fish due to drying too quickly during the initial stages that prevents adequate drying of the inner layers of fish. If too high a temperature and/or airspeed is used during drying a relatively impermeable outer layer is formed on the surface of the fish during the initial period of drying which effectively halts the drying process, and the moist interior of the fish will spoil rapidly. The same undesirable condition can occur during the initial period of smoking if the temperature and/or airspeed are too high.