Rinse the corned beef brisket under cold water, then place it in a cold water bath that you will store in the refrigerator for 24 hours. This draws the excess salt out of the beef. Do not skip this step or your beef might be too salty to eat.

In a small pan over medium heat, mix together the spice packet, coriander seeds, mustard seeds, and black peppercorns. Heat until fragrant. Place them in a spice mill, coffee grinder, or blender and pulse until coarsely ground. Mix with the paprika and garlic powder to create a dry rub. Cover and set aside until ready.

After 24 hours, remove the brisket from the water. Pat it dry.

Generously coat the entire surface of the brisket with the dry rub, pressing it into the meat to ensure it adheres.

Preheat your smoker or pellet grill 225°F (107°C). Fill the hopper with your preferred pellets.

Place the brisket directly on the smoker rack.

Smoke the corned beef brisket for approximately 4 hours, until it reaches an internal temperature of 165°F (74°C).

Quickly lift the lid and spritz the brisket all around with beer. Continue smoking, spritzing every 45 minutes, until it reaches 202° (94°C).

Remove it from the smoker and wrap it in butcher paper or foil. Place it in an airtight cooler, or in the oven with the door closed. Allow it to rest for about 30 minutes to let the juices redistribute.

After resting, slice the smoked corned beef brisket into slices and serve.