Toast the fennel seeds in a dry pan over medium heat for 2 minutes, stirring occasionally, until fragrant—this releases their essential oils and deepens their flavor. Set aside to cool. In a large pot, bring 8 cups of water to a boil, then remove from heat. Add the salt, sugar, and brown sugar, stirring until completely dissolved. Add the cooled toasted fennel seeds along with the cinnamon sticks, star anise, celery seeds, cloves, bay leaves, and peppercorns. Stir well to combine all aromatics into the brine base.
Add ice to the brine mixture from Step 1 to rapidly cool it to room temperature—this is important to prevent the meat from beginning to cook. Place the brisket in a large container or brining bag, then pour the cooled brine over it, ensuring the meat is completely submerged. If needed, use a plate or weight to keep the brisket underwater. Cover and refrigerate for 2 days, allowing the salt and aromatics to penetrate deeply into the meat.
While the brisket brines, combine all dry rub ingredients in a small bowl: brown sugar, salt, coarsely cracked black pepper, chili seasoning, coriander seed, ginger, onion powder, garlic powder, celery seed, nutmeg, and smoked paprika. I like to crack the peppercorns by hand or with the side of a knife rather than grinding them finely—larger pieces create a better textured crust when smoking. Mix thoroughly and set aside until ready to use.
After 2 days of brining, remove the brisket from the brine and rinse it thoroughly under cold running water to remove excess salt and spices—this prevents the final dish from being overly salty. Pat the meat completely dry with paper towels; dry meat will accept the rub better and develop a superior bark during smoking. Apply the dry rub mixture from Step 3 generously and evenly over all surfaces of the brisket, working it in gently with your fingers.
Place the rubbed brisket on a rimmed baking sheet or cutting board and let it rest uncovered at room temperature for 2 hours. I find this rest period allows the rub to set and the meat to come up to closer to room temperature, which promotes more even cooking in the smoker. This also gives the seasonings time to begin penetrating the surface of the meat.
Preheat your smoker to 225°F and add wood chips for smoke flavor. Place the brisket on the smoker grate, fat-side up, and smoke for 1 to 1.25 hours per pound, or until the internal temperature reaches approximately 195-205°F when measured in the thickest part of the meat. The exact time will vary depending on your smoker and ambient conditions, so use a meat thermometer to guide you rather than relying solely on timing.
Remove the brisket from the smoker and place it on a cutting board. Tent loosely with foil and let it rest for 1 hour—this allows the juices to redistribute throughout the meat, ensuring it stays moist when sliced. After resting, slice the brisket against the grain into pieces about 1/4 inch thick. Serve warm and enjoy the perfectly seasoned, tender result.