In a large bowl, combine 4 cups water, 1/4 cup kosher salt, 1/4 cup brown sugar, 1 tablespoon black peppercorns, 1 tablespoon dill seeds, and 1 tablespoon crushed garlic; whisk until salt and sugar are fully dissolved.

Stir in 1/2 cup soy sauce to enhance umami flavor, if desired.

Allow the brine to cool to room temperature to prevent cooking the salmon.

Clean and trim a salmon fillet, removing any pin bones.

Place the salmon fillet in the brining container and pour the cooled brine over it, ensuring the fish is fully submerged.

Cover the container with plastic wrap or a lid and refrigerate for 12 to 24 hours to infuse flavor into the salmon.

Remove the salmon from the brine and rinse it under cold water to reduce excess saltiness.

Pat the salmon dry with paper towels and proceed to smoke according to your smoker’s instructions or store for later use.