Before your salmon goes into the smoker, it requires a soak in smoked salmon brine, which cures the fish. When fully cured, the texture of the flesh is changed in a way that helps it remain moist after being smoked.
When using the basic salmon brine for making cold smoked salmon, it's
important that the fish remain in the brine for enough time that the
flesh is fully cured. Cold smoked salmon is not cooked, so the salt
keeps the fish preserved.
Hot smoked salmon doesn't need to be cured to that extent, although it wouldn't hurt anything if it were. For hot smoked salmon, brining for approximately one hour per inch of thickness is all that's required. Cold smoked salmon should be brined considerably longer, 4 to 6 hours per inch. However, the longer the salmon is brined, the more it needs to be rinsed of excess salt after brining.
Salmon brined to be cold smoked can require hours of rinsing in fresh water to remove salt.
This recipe is enough for up to five pounds of salmon fillets.
Stir the salt and sugar into the water until completely dissolved. It's actually much more effective to bring half of the water to a boil and dissolve the sugar and salt in the water over heat. It makes for a more effective brine, too, because the salt dissolves much more completely than it would being stirred into cold water.
After brining the salmon for the required amount of time, it's then rinsed, surface dried and smoked.
Additional flavors can be added to the basic smoked salmon brine recipe. Garlic, herbs and/or spices and other flavorings can be added. Fruit juices can be used in place of part of the water. Salmon brine can be as simple or as complex as you desire.