* I have substituted honey for the maple syrup.
I prefer to use alder wood for my salmon, but apple, cherry, oak or maple work fine.
Mix together the brine ingredients and place your fish in a non-reactive container (plastic or glass), cover and put in the refrigerator. This curing process eliminates some of the moisture from the inside of the fish while at the same time infusing it with salt, which will help preserve the salmon.
You will need to cure your salmon at least 4 hours, even for thin fillets from trout or pink salmon. Large trout or char, as well as sockeye salmon need 8 hours. A really thick piece of chinook salmon might need as much as 36 hours in the brine. Never go more than 48 hours or your fish will be too salty. Double the brine if it's not enough to cover the fish.
Take your fish out of the brine and pat it dry. Set the fillets on your cooling rack, skin side down. I do this right under a ceiling fan set on high. Let the fish dry for 2 to 4 hours (or up to overnight in the fridge).
Time to smoke your fish. Even though this is hot smoking, you still do not want high temperatures. It is important to bring the temperature up gradually or you will get that white albumin "bleed" on the meat. I start the process at 120°F for 2 hours. Then I step up the heat to 140°F for another hour, then finish at 175°F for a final hour or two. I take my salmon off once it reaches 140°F.
I add smoke for the first 3 hours, you can adjust to your taste.
After an hour in the smoker, baste the fish with the maple syrup; do this every hour. This is a good way to brush away any albumin that might form. In most cases, you will get a little. You just don't want a ton of it.
Once your fish is smoked, let it rest on the cooling rack for an hour before you put it in the fridge. I vacuum-seal it and freeze it up to a year (it never lasts that long).