In a skillet over medium-high heat, cook the bacon. Drain cooked bacon on a paper-toweled lined plate. Chop roughly. Set aside.
In the same skillet, cook shallot and jalapeño in bacon fat until softened. (Remove some of the bacon fat if there is quite a bit in the pan. You only need a tablespoon or less.) Set aside.
Lightly coat a 4 quart crockpot with non-stick spray. Add cream cheese, cheddar cheese and shallot/jalapeño mixture. Pour beer over mixture. Cover and cook on low for 2 hours. Stir occasionally until dip is creamy and cheese is melted.
Stir in bacon and cayenne pepper to taste. Serve with bread cubes, pretzels or crackers.