Arrange the beef on a wire rack over an aluminum pan and season with the beef seasoning.
Preheat the smoker to 250°F and add apple wood chunks.
Pour 12 ounces of Honey Brown Lager and 1 cup of water into each aluminum pan.
Place the beef in the smoker. After 1½ hours, spritz with apple cider vinegar. Continue spritzing every 30–45 minutes.
When the beef reaches 165–170°F, transfer it to a separate pan with 1–1½ cups of the cooking liquid.
Add the butter, cover the pan with foil, and return it to the smoker for about 1 hour, or until the beef reaches approximately 205°F and is probe-tender.
Meanwhile, combine the tamari, sweet garlic chili sauce, sesame oil, gochujang, rice wine vinegar, brown sugar, garlic, and ginger in a saucepan. Bring to a boil and cook for 4–6 minutes.
Mix the cornstarch with the water and add it to the sauce. Cook for another 2–4 minutes, until thickened. Remove from the heat and allow to cool.
Once the beef is tender, pour the Korean BBQ sauce over the burnt ends and toss to coat.
Return the uncovered pan to the smoker for 30 minutes to set the glaze.