Place fillets in plastic cling wrap.
Cover fillets with sugar-salt mixture and dill. Be very generous. No matter how many fillets you have, the ratio will be the same—e.g., 2 lb sockeye, 1 cup sugar, 1 cup kosher salt, ¾ cup chopped dill.
Wrap fillets well and place in a large flat container in the refrigerator for 12-18 hours. When the fillets are slightly hardened, remove and rinse clean with cold water. Note: Some people stop here and eat it as is—this is essentially gravlax. However, I enjoy cold smoking the fillets to add wonderful West Coast flavour.
Pat the fillets clean and dry with paper towel, and place fillets on a baking/cooling rack. Use a large fan and blow on the fillets to form a pellicle. A pellicle is a like a “skin” that the smoke can better adhere to. Typically, this step is most important in hot smoking, but it works just as well for cold smoking lox. I never skip this step either way. You’ll know it’s ready for the smoker when you touch it with your finger and it doesn’t feel sticky.
Cold smoke your fillets overnight. Do not use any heat; in fact, it’s best to be sure that if you plan to do this in your garage or outside, you do it in mild temperatures. You are not looking to cook the salmon here, you are only looking to infuse smoke. It’s critical that your smoker’s internal temperature is 80 F or less. I use a Masterbuilt electric smoker with the cold smoker.