Mix 3 parts sugar (I prefer brown) to 2 parts kosher salt
in simmering water.
Add any desired spices.
I usually use some red chili and garlic.
Not only for flavor, but because they both have preservative qualities.
For extra flavor (and preservation) I will also add some pepper, allspice, and bay leaves.
Allow brine solution to cool.
Prepare fish in hunks/strips and wash.
Put a layer of fish in a non-reactive container, skin side up.
Pour some brine solution over the first layer of fish.
Continue adding layers of fish and brine solution alternating direction.
Allow fish to brine in a cool place for 2-3 hours.
Remove fish from brine, rinse, and place in a bath of cold water to allow fish to "freshen" for about 30 minutes to an hour.
Place fish on smoking/drying racks in a cool place, with room for air to circulate around each piece of fish.
Allow the fish to dry/cure for about 12-16 hours.
Warm smoke at about 140F (130-150F is OK) for about 6 hours.
Add water until salt barely dissolves.
(We want a nearly saturated solution).
Preferably to a temperature below 38F.
Glass, food-grade plastic, and stainless steel are often considered to be non-reactive.
If you do use plastic, note that this plastic will only be useful for fish preparation in the future. It will take on some odor.
Try to stack flesh-to-flesh sides, then skin-to-skin sides.
(I was brining for 2 hours with a dry brine, but
my results were a little inconsistent.
Now that I am trying wet brine, I may need to increase my brining time.)
This should help make the salt distribution through the flesh more even.
A refrigerator is OK, but they can be a bit warm. You want something between about 30 and 38 degrees F. Cold, but not cold enough to freeze a brined fish.
A hard skin should form (called a pellicle).
The fish should reach an internal temperature of about 138F, and become a bit dry.
It should be more dried then cooked, and firm, not flakey.
If white fat/protein deposits develop on top, or the fish gets flakey,
it got a bit too hot and cooked.
This is OK, but it will not have as good a texture as if the smoke had
been cooler.