Mix flour, salt and pepper with grated cheeses in a small bowl.
In a medium saucepan, heat 10 ounces of the beer until boiling. Add grated cheese by the handful and stir each one until fully melted before adding more cheese. Once all grated cheese is melted, stir in cream cheese, mustard, Worcestershire sauce and jalapeño. Stir until combined and cheese is melted. If sauce is too thick, add the rest of the beer to get to desired consistency.