Pat the salmon dry with paper towels and cut it into equal portions (typically 6-8 pieces depending on size). In a shallow dish, combine 1 cup of the dark brown sugar with the juice of 2 lemons, stirring until the sugar begins to dissolve into a wet paste. This mixture will cure the salmon and draw out moisture while infusing it with sweet and tart flavors. Place the salmon pieces skin-side down in the dish, ensuring they're evenly coated with the brown sugar mixture. Cover and refrigerate overnight—this is crucial for developing flavor and creating that caramelized crust when grilled.
About 30 minutes before grilling, remove the salmon from the refrigerator. In a small bowl, whisk together the remaining 3/4 cup brown sugar with the juice of 1 1/2 lemons (about 4-5 tablespoons), 1 tablespoon soy sauce, and 1/2 teaspoon smoked paprika. Stir until the sugar dissolves slightly and the mixture reaches a brushable consistency. I like to taste this glaze before grilling—if it feels too sweet, add a tiny squeeze more lemon juice. This glaze will caramelize beautifully on the grill and add depth with the salty-smoky notes.
Preheat your grill to 350°F and lightly oil the grill mat to prevent sticking. Remove the salmon from the curing dish (discard the curing liquid or reserve for another use) and place the pieces skin-side down on the grill mat. Brush generously with the glaze from Step 2, then grill for 5 minutes before brushing again. Repeat this brushing every 5 minutes, building up layers of caramelized glaze. I always set a timer for these 5-minute intervals—it keeps the salmon from drying out and allows the glaze to set and caramelize without burning.
Continue grilling and brushing until the salmon reaches an internal temperature of 145°F at its thickest point (usually 15-20 minutes total, depending on thickness). Remove the salmon from heat immediately once it reaches temperature—this prevents overcooking and keeps the fish moist and tender. The exterior should be deeply caramelized and the flesh should flake easily when tested with a fork. Let the salmon rest for 2-3 minutes on a warm plate before serving.
