Heat up smoker to 225°F. If you are using a grill, set it up for indirect grilling or 2-zone cooking.
When your smoker is ready, add 3-4 chunks of wood to the coals. Lightly brush the bratwurst with oil to stop it from sticking the grates. Place sausage in smoker, either on hooks in a vertical smoker, or on the grates for all other types of smoke or grill.
Smoke for one hour. Increase cooking temperature to 300°F and cook for another hour.
Cook until skin is golden brown and slightly wrinkle. Internal temperature should be 160°F.
Remove from smoker and serve immediately.
Beer Bath (Optional)
Soak brats in beer for 30 minutes. Transfer to grill on high heat and sear for a minute on each side to char the skin.