The Liquid Smoke is not needed but I recommend adding it to enhance the flavor.
A single heavy-bottomed saucepan is the only piece of equipment required to bring this condiment together. Ketchup provides a stable tomato base loaded with natural pectin and vinegar, while bottled apple cider vinegar introduces sharp malic acid that cuts through heavy sweetness. Pouring the vinegar directly into the empty ketchup bottle captures residual solids clinging to the glass walls, ensuring zero waste. Butter melts into the warm mixture to supply dairy fats that coat the tongue and temper the heat from red pepper flakes. Heat the liquid over medium energy until small bubbles form at the edge, but never allow a rolling boil, or the dairy fats will break and separate from the tomato solids. Whisk continuously during this heating phase to dissolve two packed cups of brown sugar completely without scorching the molasses. Liquid smoke offers concentrated guaiacol compounds that mimic open-fire cooking without actual charcoal exposure. Store the finished condiment inside a sanitized glass container for up to two weeks in the refrigerator. Pair this pungent condiment with grilled pork chops or smoked brisket, where the high sugar content caramelizes under direct heat to form a sticky crust.