Place your brining bucket or cooler in a cool spot and ensure it is food-safe and large enough to fully submerge the turkey.

Pour 1 gallon of water into a large pot and bring to a boil over high heat, then stir in 1 cup kosher salt and 1 cup packed brown sugar until dissolved.

Add black peppercorns, bay leaves, smashed garlic, thyme sprigs, rosemary sprigs, juniper berries, allspice berries, whole cloves, and red pepper flakes to the hot brine and let infuse for 2 minutes off heat.

Pour the hot brine into the bucket, add the remaining 1 gallon of cold water and 1 to 2 pounds of ice, and stir until the temperature drops below 40°F using a thermometer.

Remove packaging from the turkey and pat it dry with paper towels, inside and out, then remove any pop-up timers.

Submerge the prepared turkey breast side down in the cooled brine, weigh it down if necessary, and ensure full coverage.

Cover the bucket loosely and refrigerate or keep in a cold location below 40°F for 12 to 24 hours.

Remove the turkey from the brine, discard the brine, and pat the turkey dry thoroughly with fresh paper towels.

Let the dried turkey sit at room temperature for 30 to 45 minutes before placing in a 225°F smoker for 3 to 4 hours until the internal temperature reaches 165°F.