In a medium bowl, add the brown sugar, onion powder, garlic powder, mustard powder, smoked paprika, pepper, tarragon, and salt and stir to combine. Use half of the spice rub to season the entire chicken. Cover with plastic wrap and refrigerate for at least 2 hours or up to overnight.
2. Step
Preheat the grill to 350°F (190°C).
3. Step
Remove the chicken from the fridge and season with the remaining spice rub. our out half the can of beer. Place the half-filled can in the chicken cavity and stand it upright.
4. Step
Grill the chicken over indirect heat for 30-40 minutes. Baste the chicken with barbecue sauce and cook for another 10-15 minutes, until the internal temperature reaches 165°F (75°C).
5. Step
Remove chicken from the grill and let rest for 15 minutes before carving.
