In a bowl, combine the shredded cheddar cheese and flour. Stir to coat.
In a saucepan over medium heat, add the beer and bring to a quick boil.
Lower the heat to medium-low, then add the cheddar cheese, cream cheese, jalapeño pepper, garlic, salt, and pepper to the mix. Stir well to combine and until the cheese is melted and incorporated into the sauce.
Continue to simmer over medium-low until the cheese dip reaches your preferred thickness, then remove from the heat (note it will firm up as it cools, so consider this while measuring thickness of the dip while over heat).
Serve immediately while warm.
Want it spicier? Try a pinch of cayenne in the dip itself. This will add a level of heat through the entire sauce, not just the jalapeño pieces.