Whisk together mustard powder and 1/4 cup of the Coors Light in a heat proof small bowl and let sit at room temperature for at least 30 minutes.
Meanwhile, bring 1 inch of water to a simmer in a small pot.
Add liquid smoke, garlic, cayenne, jalapeno, paprika, black pepper, and cumin to mustard mixture and whisk to combine.
Place the bowl over the simmering water (the bowl shouldn’t touch the water) and cook, stirring frequently, until the mustard is slightly thickened and yellow-brown and the taste has mellowed a little, about 7 to 10 minutes.
Whisk in remaining beer to thin out the mustard, cover, and immediately refrigerate.