The first requirement for cold-smoking is to keep the temperature in the smokehouse or smoke chamber cool. Usually, this requires having the fish a good distance from the fire or source of heat, as discussed in Chapters 5 and 6. It’s best to keep the temperature below 90°F, and certainly below 100°F. I consider 70°F to 80°F ideal.
If the salt cure was sufficient to be on the safe side, you can cold-smoke the fish for a few hours, a few days, or a few weeks. As a general rule, the longer the fish is smoked, the more smoky the flavor; but at some point the law of diminishing returns sets in and the smoking, if done in a dry atmosphere, becomes more of a drying period than a flavor-enhancing period.