After the fish are treated with either a brine or a salt cure, they should be washed and dried before putting them into the smoker. The drying helps in a number of ways, but basically it forms a pellicle, or glazed film, on the surface. This film helps give the fish a better and a more uniform color, and it may also aid in preservation.
After washing the salt from each fish, pat each one dry with paper towels and place it on a rack (or hang it) in a cool, breezy place. If you don’t have a natural breeze, a fan will help. Usually the pellicle will form within 3 hours or less, depending on the size of the fish. After the pellicle forms, proceed with the cold-smoking operation.